Our Third Issue

We are absolutely delighted to continue to count with the support of writers from different parts of the world, whose articles make this e-bulletin worth reading. After all, this is an international bulletin. Bruce's article on some of Taiwan's guppy secrets takes us deep into Taiwan's guppy subculture. It is interesting that Bruce's article on Taiwan, and Tomoko Young's article on Japan, both elude to the emergence of regional methods for raising guppies. We are honored to be able to present these articles in our e-bulletin. We think that the Internet can expose some of these deeply rooted local traditions, or secrets to the rest of the world and that the benefits can be significant. We were able to see some differences and similarities in their respective approach, and were perhaps a little surprised at both.

Chris' article about the GCS is exactly the kind of article we hope to publish about international guppy news. Did you see who the judges were for their guppy competition? Tomoko's article about shipping guppies should be of interest to all of us. After all, what would be of the hobby without being able to distribute guppies around the planet? Sergio's article on biological filters for water recirculating systems provide tons of technical information as well as practical examples with guppies. It is work in progress for those of us interested in this subject. And Enrique's article reviewing studies about the inheritance of growth in guppies should also be of practical value to us in our fishrooms. We have introduced a new Short Communications column in the bulletin, where we will present short articles under one column. In this issue, we are also including abstracts from three recent scientific publications on guppies.

So, what is next? We are very happy with the results so far, and are hopeful and excited to continue with the current format into the future. We will continue to work with writers using the current format. Also, at some points or intervals, we may consider releasing special issues in subjects such as: Guppy genetics, guppy nutrition, guppy immunology and health management, systems design, etc. Our first special issue will be about guppy genetics and should come out on or before January 2005.

Enjoy reading and please e-mail this e-bulletin to guppy-people you know.

 

Guppy Scene Of The Lion City

There is a steady interest in the guppy in Singapore. Apart from being known as one of the world’s largest producers of fancy guppies, in the 1970s there were also many awards from active participation in international shows.

Guppy farms in Singapore are consistently improving their stock and creating new varieties or strains, such as Japan-blue blue diamond. Individuals growers had imported fancy guppy strains from overseas and developed their own...

Young Japan blue blue diamond male and purple tail male

Guppy Club

The Singapore Guppy Club was formed in the late 1960s, which actively promoted the appreciation of guppies through fairs and other events. Crowds gathered wherever there were any guppy shows. But due to the shift of focus to commercial production, the public attitude towards fancy guppies in Singapore became less positive…

The millennium brought good news. Via the Internet, more Singaporeans became more aware of fancy guppies and better informed, and people began viewing guppies in a more positive light. Guppy enthusiasts started getting together again and continued discussing more about the fish they loved. Over time, The Guppy Club (Singapore) was revived.

The Guppy Club (Singapore) http://www.sgguppy.com/ (GCS) was officially registered on 14^th Feb 2004, and a series of activities were planned to further create awareness about fancy guppies.

Singapore Guppy Open House

The first open house was held on 10^th April 2004 at a member’s home. Response was great!  Guppy enthusiasts gathered to meet up with each other and also register themselves as members of the club. A talk on red guppies and an auction allowed members to know more about their fishes and acquired new guppies.

First Singapore Guppy Competition

The 1^st GCS National Guppy Competition was held on the 29^th May to 2^nd June 2004 at the Bukit Timah Plaza. There were 96 entries in the 6 classes available.

100 tank setup

GCS booth

Some fishes in the show

Six classes

a. Solid Single Colour / Plain tail

b. Tuxedo (Half/Blacks).

c. Mosaic - all colours.

d. Grass - all colours.

e. Snakeskin/Cobra

f. AOC - all colours

g. New Strains/Open

Judging criteria:         

 Focus Areas Standards               Overall allocation of points:

a. Length of fish                            1. Body – 25%

b. Shape of fish                            2. Dorsal – 25%

c. Pattern of fish                          3. Tail – 50%

d. Colour of fish                          4. Overall – 100% (Additional points/penalties included)

This was a major event organized by the GCS, and we consider it a success. Crowds gathered to view the competing (matched pair) male guppies, which delighted the adults and children with their beautiful finnage.

At the GCS booth, there were sales of fancy guppies such as ribbon blue grass, albino galaxy, etc., at affordable prices. That coupled with lots of freebies, stimulated lots of interest in guppy keeping. The GCS members are spotted mingling around the show area, readily sharing experiences and knowledge with the members of the public. Some guppy enthusiasts who had kept a low profile also came to the show, where they shared their guppy experiences with others.

The judges for this GCS National Guppy Competition were Professor Violet Phang, renowned guppy researcher, Ms. Pauline Teo, Director of Teo Way Yong & Sons Pte. Ltd. and Mr. Richard Woon, President of the former guppy club. The judges have extensive knowledge about guppies, which greatly benefited the participants as they pointed out the merits and demerits of certain fishes and the entries in general.

This has been a good start for the Guppy Club and I believe that the hobby will reach greater heights in Singapore.

 

A Popular Automated Water Changing System

There are many reasons why we breed guppies; enjoy their beauty and company, see through the cycle of life, make our own strains, meet new friends, win shows, and some make extra income. The list can go on and on. But like everything else, there is always the down side. Among the top of the list, and certainly in my case, has to be the time spent for the water change. You know this is true if you own around 50 tanks like me. And I can certainly feel your pain and suffering if you have more than 100 tanks. For breeders who own more than 200+ tanks and have to change water by the old fashion way of siphoning and hosing water in from a nozzle, I truly sympathize for you.

Time is money! For those of you who aren’t old enough and some, like me, who are almost old enough but just plain too broke to retire, we know this is also true. Here is a popular automated water changing system adopted by most of the large scale breeders in Taiwan, which will facilitate breeders like me and alleviate some of the burden of changing water for the large scale breeders.

My friend, Lin Sheng-Hwei, who befitted about 72 36-liter (about 7.5 gallons) tanks with this system and the total amount of time he spends to change 80% of water for all 72 tanks is about 25 minutes. That’s over 400 gallons of water change in 25 minutes!

We all had some bad experiences with the overflow of water; a phone rang or someone called you away while filling up the tanks, or in my case, getting old and forgetful. But with this system, there is absolutely no chance for overflow.

Here is the basic set up:

2 – Glass partition for the gravel and undergravel filter. 4 – Undergravel filter with legs which raise the filter about one inch off the bottom (purple) 6 – Partitioned area for the gravel and sized perfectly to fit the filter. 8 – Water outlet (flanged and O-ringed to prevent leaks) 9 – Outlet piping, approximately 1-inch inner diameter plastic piping (red) 10 – Flow valve (green) 12 – Inlet piping, same size piping as outlet (actually L-shaped and not slanted like in the diagram) (blue) 14 – Water inlet valve, same size piping as outlet (green) 16 – Overflow outlet, approximately 1/2 to 5/8-inch inner diameter 18 – Overflow piping (orange) 20 – Under-gravel filter outlet (inverted L-shaped at the top) 30 – Partitioned tanks(or in Lin’s set up, individual tanks)

This is how the undergravel filter looks like

Here’s a photo of a multi-tank set up:

I personally think this masterpiece of design was the result from someone’s or collective experiences from many breeders. As of this moment, I still don’t know who had originally come up with this design. But here are some of the principles behind this system:

1.          Overflow outlet prevents any water flow unto the floor while adding water to your tank.

2.          Self-cleaning. First thing that gets sucked out is the accumulated excrement in the gravel.

3.          Inverted L-shape blasts any excrement in the front to the back.

Here are some more details to this design which were not in the diagrams:

1.        Plastic “air distributors” instead of air stones are used for all under-gravel filters. Air stones get clogged easily and require extremely large amount of air power, and hence, shorten the life of an expensive air pump.

2.        Overflow outlet sticks out slightly and capped by a net material to prevent any fish who wants to take an adventurous ride down to the sewage system. (Not capped in Lin’s system.)

3.        Large sized gravels, 1/8 to 1/4 in diameter, which harbor lots helpful bacteria, serve the best in this system (size really depends on the thickness, or amount, of the gravel and the flow speed through the gravel). To have an affective undergravel filtering system, the ability to harbor helpful bacteria by the gravels is probably the most important factor.

4.        The overall speed to change a certain amount of tanks in this system really depends on the inlet water flow rate. If you want speed, installing a water pump at the inlet water supply is highly recommended.

5.        Air piping not showing. See picture

6.        Inlet piping is capped and a small hole drilled in the middle to create a funnel or an orifice to control the flow.

7.        Air stones can be opened and cleaned. Life time usage!

After chatting with Lin, here’s one suggestion he made to improve this system. The partition which boxes in the gravels can be lower than what he has now. He sometimes has the problem of clogging due to the large amount of gravels. To solve the clogging problem, he has to poke or stir up the gravels with a stick while draining the water. He thinks about half the amount of gravels will accomplish the same task.

The initial set up for this system could cost money and require man power. It takes lots of piping, flanges, L-connectors, T-connectors, and custom-made tanks with two predrilled holes in each. All Lin’s tanks are tempered, so the holes have to be cut before they are annealed. Like everything else in business, the cost can be calculated and the hours required to install this system estimated. Then you can evaluate and ask yourself if this is a good investment for your fish room and your future.

 

 

Since I have been in guppy breeding in United States, I can't even remember how many times people have asked me why majority of Japanese breeders can be successful breeding guppies using undergravel filter and small tanks. And my answer to the question has always been enough to satisfy the people who asked me.

Guppy is the famous well known fish who has very delicate caudal, and that's one of the biggest reason for failure using this filtere, specially among show breeders in United States. The poor chemistry often destroy the delta caudal which is the trademark of American show guppy. Some known breeders believe that undergravel filter cannot support the heavy feeding which is required for raising the large size guppy. As the most common result, people give up to use it within few month before the good bacteria start to grow on the surface of gravel.

Anyway I try to introduce today how Japanese have received the benefit by using undergravel filter systems, and how we overcome the common problem and got success to establish our unique regional breeding style as the whole country's official setting.

Also many thanks to both Enrique and Sergio for language support. I couldn't finish this article without their encouragement.

These pictures are from Mr.Shinichi Kobayashi, who is the owner of Studio Poecilia, in Suwa City, Nagano, Japan. Studio Poecilia is a famous guppy shop around the world through Internet for his creativity. Mr. Kobayashi is very successful to use both undergravel filter and plants for part of the 600 tanks in his shop. His growing methods basically rely on the natural biological power of gravel & plants.

When I visited Studio Poecilia couple years ago, I was really thrilled to see how one person could take care of so many tanks without any recirculating system or or assistant employees. All he got was the classical Japanese setting with river sand which is called " Oiso ", and just so many quantities of small tanks for cross experimentations. It was absolutely stunning.

Some of the water he uses for breedingis is slightly green in color. All the fish are healthy and lively, especially fries look happy in that water. He tells me that all the things he does are in purpose, by his faith and confidence from his own long experience of actual breeding, not just from the knowledge of books.

He says his basic daily maintenance is changing water once a week, and it's good enough for his fishroom. Also he mentions that he is occasionally clean the whole tanks as well as other Japanese breeders do, and this work cause a lots of task for him. What this work is called in Japanese word " Maru - Arai " is the biggest pain job for breeders. In order to decrease the amount of this hard work, some breeders are using liquid bio bacteria extract . And seems it works for protecting male caudal too.

If any of you have chance to go visit to Japan, try get out from Tokyo sometimes with local train for seeing Mr. Kobayashi & his guppies. His place Suwa is located deep inside of central Japan which was the capital of the ancient Japanese culture. I guarantee you will discover special treasures there...! These are some of Mr. Kobayashi's guppies.

 

From Hawaii

This are parts of my fishroom. Slightly dirty with green algae...It has been 3 years since established. Have never bleach any of tanks and filters yet. In the first year, there were disease attack couple times , but after that less troubles month by month. And now finally no problem with real heavy feeding - average 5 times a day.

I normally change 80% of the water once a week, but basically want to escape from this job as much as possible. I sometimes dump a capful of liquid vitamins into each tank. Or constantly mixed with baby brine shrimp when I feed to guppy, so the tank water can stay O.K. for 2 weeks maximum.

In fact there are various different settings in my guppy room and I try to compare how the results are in each setting - undergravel filter, sponge filter, corner box filter, outside power filter, plants with plain bare tank without any filtering and also a water recirculating system which I'm learning from my husband who has been in saltwater aquarium fish industry for 35 years. See above pictures which protein skimmer & bioball tower I rely on. And the fact that the professional water recirculating system gives the best result and needs much less maintenance.

However I would like to say here that undergravel filter is also almost good like a system once it works - even it's the oldest and the most classic method. One very known marine aquarium fish breeder in University of Hawaii has been adopting undergravel filter with coral sand for breeding his Centropyge angelfishes since a while ago. And he is also wondering that the percentage of survival of fries are much higher than using his expensive recirculating system.

Maybe we need more research for a while about this subject ...

These are some of my guppies...

Adopting saltwater fish packing techniques for shipping guppies

I would like to share a little different way to pack guppy which I learnt via my family who is a long time experienced exporter of saltwater aquarium fish. Since I have switched to this method from standard guppy packing, Seems like guppy last longer and healthier, also less percentage of accidental DOA during the long distance transportation.

These are the stuffs I'm using for actual shipping and it's quite simple !

(1) Thick & double 5" shipping bag with new papers.

Newspaper is for fish to be relax and calm down. Also if the water leak from the shipping bag during transportation, newspaper take care of it. Using thick nylon shipping bags is for protecting fish from bag breaking by air expansion on the airplane.

(2) High density styro foam box

(3) Heating pack ( only during winter season ) or ice pack (only during the hottest season)

(4) Shipping water with a mild antibiotic (nitro furazone) or bag buddies

Try give the priority of fish health and survival than saving $ 5 to $10 shipping cost. Use extra amount of water instead of too little water. If the shipping cost become overprice than your pocket money, then maybe have to throw some water.

(5) Oxygen

Always use it. Never forget . Actually guppy can ship without oxygen but the risk is high and you would notice that guppy were often gaping for suffering from oxygen starvation in the shipping bag , or either would die within 1 week after acclimate.

(6) Clipper

This is typical saltwater fish packing material. Works great for fresh water fish packing too.

See how simple it is. Here is also pictures of mass packing...

Other sources of information:

Shipping Practices

Packing Guppies

 

 

Sizing a Trickling Biofilter:

Part I – Estimating Waste Production and Oxygen Demand.

In my last article I went into something that I intended could be helpful for both, the too lazy and the too busy guppy breeder. Here I shall deal with harder subject. In this article I will go deeply into our more secret dream or wish, to get rid the boring paleosoic hose and bucket system and build a water recycling system.

We have two options in order to decrease the concentration of  harmful compounds in the aquarium water: (1) change the water or (2) recycle the water. Although you might be able to get rid the hose and bucket simply using an automated water change system, I sincerely think that soon or later, all among us will shift to recycle. Do not think I’m another green". Surely I am not. I am just concerned about the most sensitive part of my person, my pocket... You could say  that recirculating systems don't work for guppies. OK, perhaps you’re right, but the same was said about artificial feeds. A few decades ago it was impossible to reproduce and to grow fish feeding them only on artificial feeds. Right now, at least for the most important commercially cultured species, is possible to produce fish, generation after generation, only on artificial feeds. Do you know what makes that possible? The experience, the background, the practice. I just think its the same with water recycle systems. As soon as we begin to use them, the sooner we will know how use them. But for those still skeptical about this subject, I hope that the data presented here help you understand better design concepts and build a more rational water management system.

For an introduction to the topic of biofiltration, I suggest you take a look in the documents available at Aquanic site. Reading the series of web pages on that site is a great way to immerse yourself in the topic in general. What I try to do here is to make this subject relevant for guppies and other important ornamental species.

This article is based in a spreadsheet I developed to size a trickling biofilter for my fishroom. My spreadsheet is similar to the spreadsheet developed by Losordo and Hobbs (2000) to size biofilters for food fish raising plants.

Since almost there is no data about designing recycle systems for guppies or tropical ornamental fishes I am joining pieces of information from many different sources. I was intended to cheat Murphy’s law. But to write about all the infromation available in only one article proved to be impossible, so I spread these information in two pieces. For now we are publishing Part I, related to estimating waste production and oxygen consumption. Part II, which deals with sizing the biofilter sizing itself, will be published in our next issue.

Colt (1986) proposed a “Mass Balance Approach”  for the design and operation of fish culture systems. “  This method is based on identification of the critical environmental parameters that may limit the growth of fish. These may include, dissolved oxygen, carbon dioxide, ammonia, and solids. Based on laboratory and production experiments, a water quality criterion is set for each parameter. Then the water flow required to maintain each parameter is computed for the specific hatchery conditions.”

I chose a trickling biofilter because I can mange at least three of the four critical environmental parameters. Trickling biofilters remove ammonia, add oxygen to the water and can provide some carbon dioxide stripping with relatively low costs for start up and operation. 

We know that the amount of metabolism byproducts released by fish into the system is proportional to the amount of feed consumed (Haskell 1995), cited by Ng et al. (1983)  Our first step is to estimate the amount of feed released into the system. We can do that by entering data on the system configuration, its management, and the fish biomass and daily feed allowance can be estimated. The second step is to estimate the amount of metabolites produced by guppies fed this specific amount of feed. There are different methods found in literature which are suitable to estimate total ammonia nitrogen (TAN) production (indeed size the biofilter), total suspended solids (TSS) production (indeed size a solids removal device) and nitrate production (indeed estimate the need of the system for new water), among others metabolites. The third step is to estimate the amount of oxygen consumed by the fishes, by the water biochemistry and by the biofilter through the nitrification process. 

The Spreadsheet

If you want a copy of the spreadsheet, e-mail me.

1 – System and Management Related Parameters.

1.1 – Total Volume of Water

 This is the total volume of water held by all tanks connected to the filtering unit being sized, it is expressed as liters (l).

The rack at my fishroom is divided in 3 levels. In the upper board I have eighteen 20l aquaria used to house breeding trios, females about to delivery and young frys. At the middle and lower boards there are fourteen 40l aquaria per level used to house breeding groups, older frys and growing sexed fishes. This arrangement is compatible with the thermostats we have available in Brazil and when associated with heaters of  different power it had allowed me, until now, have some age specific temperature control.  Due sanitary reasons and because if I wanted recycle all this water in only one filter  I would need much more energy for pumping the water through the whole height of my rack I decided to set one filter per board.

Then a filtering unit for the middle or lower rows of my rack should handle 14 X 40l and I should type “560” or “=14*40” as answer but without the quotation marks. Let’s say you want size a filter for a system with different tanks, let’s say you have eight 20l, twenty 40l and five 60l aquaria, so you would type “=(8*20)+(20*40)+(5*60)”.

This is the mass of the largest fish will be raised in the tanks connected to the filtering unit being sized, it is expressed as grams of body weight (g bw).

Usually we take management related decisions based on fish age instead fish weight. To know the mass of the guppies at different ages we should know their growth curves. Because I have not an analytical scale I had to figure some estimates on the growth curve of  fancy guppies. The basic data for this guessing exercise was taken from Shim and Bajrai (1982).  I worked on their data basically because: (1)  they used a raising method somewhat similar to the one we practice (segregated sexes, 12 fishes in 33l of water, once a week 1/3 water change, 1ppt of salt in the water, aeration, pH 7-7.7, temperature 27-28ºC, once a day feeding in “all you can eat” style); (2) there were treatments were they fed the fishes on tubifex that is recognized as a great feed for growing guppies, but they also used Aquavite, an artificial food, that surprisingly supported the same growth rate as tubifex during experimental period; and (3) they used a strain of fancy guppies as test animals. This study only covered the exponential growth phase (5 to 20 weeks old fishes) so I estimated the subsequent growth until their growth curves reached a plateau characteristic of  the expected sigmoidal shaped curve. I did so estimating the evolution of their percentile weight gain and calculating the expect body weights for ages subsequent to the finish of experimental period. This plateau I make reference is not exactly a zero growth state like represented in the graphics but a state were percentual weight gain approach zero but fish yet keep growing.

Figure 2 – Growth Curve of Female Guppies Fed Tubifex or Aquavite Artificial Feed. Adapted from Shim and Bajrai (1982).

Figure 3 – Growth Curve of Male Guppies Fed Tubifex or Aquavite Artificial Feed. Adapted from Shim and Bajrai (1982).

 Also like most among us simply don’t have access to analytical scales but to rules I planned to create a mathematical model to express lenght-weight relationship for guppies of different sexes. Unfortunately I had no access to a reliable and significant data set which allowed me to properly calculate this model. But using a limited data set covering 31 means for females and  15 means for males of fancy guppies strains and  the spreadsheet software tendency projection tool it was estimated the equations and curves in figures 4 and 5. Since their R² values are quite high I’m comfortable to use these suppositions.

Figure 4 – Length–Weight Relationship for Female Guppies. Adapted from Several Sources.

Figure 5 – Length–Weight Relationship for Male Guppies. Adapted from Several Sources.

 Perhaps you yet know that all these above are some kind of fake science but it is the best I could to do considering the complete lacking of data covering fancy guppies.

Itzkovich (2002) stated that guppies raised in Israel reach market size (3.5-4cm) at 2.5-3 months age. From figure 2 we see that a 2.5 months old (or ~77 days old) female guppy should weight 0.280g if fed tubifex or 0.315g if fed Aquavite; and a 3 months old (or ~91 days old) female guppy should weight 0.360g if fed tubifex or 0.415g if fed Aquavite. From figure 4 we see that for these body weights they should measure 30mm. 31mm, 32mm and 34mm, respectively. Inversely, by these models females guppies should reach 35mm and 0.465g when 98 days old if fed Aquavite and when 105 days old if fed tubifex, and 40mm and 0.700g when 135 days old if fed tubifex. Theoretically females fed Aquavite should never reach 40mm and/or 0.700g.  May be these models need some refinement.. If you have any data or idea to improve this model I’ll be glad to hear you.

Well, back to example of my fishroom. Like I said the middle and lower boards of my rack are for growing fishes and breeding groups, so the heavier fish I expect house there are breeding females around 2g.

 1.2– Maximum Stocking Rate.

 This is the maximum number of fishes expected to be raised per unit of water volume, it is expressed as fishes per liter (fishes/l). Al thought most authors make reference to the number of fishes stocked per unit of water volume as stocking density I personally think that “density”  is somewhat  more related to a relationship between weight and volume (gram per liter or kilo per cubic meter), so when possible I make reference to the relationship between the number of individuals and volume of water as stocking rate.

Kaiser & Vine (no date) investigated the effect of  stocking rate on growth, fin development and survival rates of juvenile fancy guppies in a closed recirculating system. They used 21x29x23cm aquaria holding 12l of water at an exchange rate of 3 exchanges per hour, 16h light and 8h dark light regimen and temperature set at 24°C. The fishes were fed 2 times a day  on commercial flaked diet slightly in excess of what they could consume within 20 minutes and uneaten food was siphoned once daily. The treatments were stocking rates of 1,3,6 or 12 fishes/l.

Figure 6 - The Measurement of Body and Fin Dimensions in Male Guppies. From Kaiser & Vine (no date).

 These authors found that different stocking rates did not have any effect on the weight gain and on the growth in standard length of male guppies. In average male guppies gained 2.54± 0.31mm and 0.14g per fish after 11 weeks. But total length gain differed significantly between treatments where fishes at lowest stocking rate grew 0.12mm/day, while there was no difference between the other 3 treatments, which averaged 0.09±0.01mm/day, suggesting a better fin growth at the lowest stocking rate. Also male guppies developed their caudal fins faster at the lowest stocking rate, while there were no differences between the other 3 stocking rates. At the end of the study the ratio of caudal fin height to standard length averaged 0.74±0.029, 0.67±0.24, 0.64±0.029 and 0.63±0.026 at 1,3,6 and 12 fishes/l, respectively.

Citing Kaiser & Vine (no date)  “In female guppies the effect of stocking rate on growth was more pronounced than for males. The significantly highest growth in gain was recorded for the lowest stocking density (p<0.01), the second highest for a stocking density of three fishes per liter (p<0.05), while there were no more differences between the two other densities. Standard length and total length dev elopement were highest at a stocking density of 1fish/l but did not differ between the other 3 treatments.” Survival rates were not significantly different between treatments and exceeded 75% at all stocking rates. 

Itzkovich (2002) described how guppies are cultured Israel using tanks provided with pre-maturated internal filters, just like our box filters and technically called upflow submerged filter, corresponding to 10% of tank volume, which are filled with plastic media and with 5-10% daily new water change. He reported stocking rates of  2.000-4.000 frys (1 to 30 days old) per 500l, 10.000-30.000 male or female growing fishes (31 to 90 days old) per 20m³ and 300 breeders (250 females + 50 males) per 500l. This author also stated that these guppies reach market size (3.5-4cm) at 2.5-3 months age.

Fernando & Phang (1985) when describing how guppies were cultured in Singapore reported that they were raised in cement tanks without aeration  but with about two-thirds of the water in the tanks being siphoned out an replaced every 1-3 days at stocking rates of  140-300 frys/m³ (1 to 17-21 days old), 160-320 growing males/m³ (22 days to 3-4 months old), 100-200 growing males/m³ (4 to 6 months old)  and 115-180 breeders/m³. These authors didn’t made any comment about it but I saw a tendency of  larger tanks  to support more fishes per cubic meter of water than smaller ones.

IFGA recommends aeration/filtration, 20-40% water changes per week and  twenty to twenty five guppies per ten gallons (fish that are 5-7 months).

Taking the data from Itzkovich (2002) who reports the highest stocking rates breeding females would need from 1.66 liters per fish (if I take males into account, 250 females+50 males per 500l) to 2 liter per fish (if I don't take males into account because they are relatively smaller than females, 250 females per 500l). The same author also states that 30.000 growing fishes could be housed in  20m³ or 1.5 fishes/l. All said I assumed a possible stocking rate of 1 fish/l. This do not mean I’ll use this stocking density but only my filter will be able to manage the waste produced at this stocking rate.

1.3– Maximum Feeding Rate.

This is the maximum amount of food dry weight a fish will be fed, it is expressed as percentage of body weight (% bw).

Feeding rates usually do not fit well when calculated based in feed weight as it does when calculated based in feed dry weight Shim and Bajrai (1982). It is much more significant for those who use feeds which huge differences in water content like artificial/live/frozen feeds and pastes. So I suggest you enter/understand feeding rates in dry matter basis, at least for feeds that are moisture rich. Table 1 show the proximate dry matter of common guppy feeds.    

Shim and Bajrai (1982)  wrote about it about guppies that were 5 weeks old in the beginning of their experiment and were raised up to they reached 20 weeks age “ The fish were fed once daily. The amount of food given was initially about 10 percent of the body weight. In cases were the dry matter is very low like in Moina, for example, the amount given was raised such that the dry matter on which they were fed would be about equivalent to the amount of dry matter for the other food types. However with experience, it was found that the constant percentage rates far exceeded the appetite of the fish. Lower amounts of food had to be given to prevent food wastage as well as to get a more accurate measurement of the od food consumed.”

Itzkovich (2002) reported feeding rates about 5% of the total biomass daily.

Usually warm-water food fishes at early life stages, if kept under optimal temperatures, are fed 10-30% body weight, at later growth stages the feed allowance is reduced to 3-10% body weigh until maturation and it reaches 1-3% body weight for brood fish. So I assumed a conservative 10% body weight daily feeding for breeding females.  

1.4 – Diet Crude Protein Content.

This is the relative amount of protein contained in the whole diet served to the fishes, it is expressed as percentage of feed (% feed).

When I say whole diet I mean take into account the proportion between the different feeds you fed to your fishes and their individual crude protein content.

Ebeling (no date) mentioned that in the aquaculture environment there are four primary sources of nitrogenous wastes; (1) urea, uric acid and amino acid excreted by the fishes; (2) organic debris from dead and dying organisms, (3) uneaten feed and feces and (4) nitrogen gas from atmosphere. We know that among these four sources of nitrogen the two most important for us are #1 and #3 and they correlated to the feeding. Also we know that the nitrogen content of the food is closely related to its protein content. He  also states that “A general rule of thumb is that about 3% of daily feed ends up as ammonia-nitrogen in the water, Al thought this is also a direct function of the protein level in the feed.”. Actually when you read the label in a feed package and you see  that it has 40-50% crude protein, you are not really buying a fed having 40-50% amino acids that is which truly made up proteins, but you are buying something that was analyzed, or something made up by ingredients which were invidually analysed, for its/their nitrogen content and this nitrogen content was multiplied by a constant (6.25) based on the assumption that proteins contains 16% nitrogen (NRC, 1993). Then at least na article, Losordo and Hobbs (2000) estimated TAN based in this fact.

I strongly recommend you standardize this data as percentage of dry weight, instead percentage of feed, because experimental diets usualy average 90% dry matter like most artificial feeds. Also Follow a table where you can see the proximate analysis of some few ingredients and feed commonly used for guppies. 

Table 1 – Proximate Moisture and Crude Protein Contents of Common Guppy Feeds. From Several Sources

        * - Estimated Moisture Content.

        * - Estimated Moisture Content and Crude Protein.        

1.5– Fish Biomass.

This is the total amount in weight (mass) of fishes to be raised in the system being designed, it is expressed in grams of body weight (g bw).

Fish biomass was calculed multiplying the total volume of water by maximum fish weight by maximum stocking rate.

1.6– Daily Feeding Allowance.

This is the whole amount of feed expected you will input into your system daily, it is expressed as grams of feed per day (g/d).

Daily feeding rate was calculated multiplying fish biomass by  maximum feeding rate.

2 – Estimatives of Waste Production.

Several researchers had worked to generate data to suport the rational design of aquaculture systems, with or without reuse of water, but they had mostly worked with cold water salmonid species. We can cite Colt (1986) who stated that 1lb of feed fed to salmonids demande 0.20lb of oxygen and produce 0.30lb of ammonia, 0.30lb of fecal solids and 0.28lb of carbon dioxide.

Ng et al. (1983) were the only ones, as far as I know, that studied metabolite production rates of tropical ornamental fishes but sadly they didn’t included guppies in their study. Below is parked a table 2 which I adapated from the results of  their studies including some basic statistics. Their findings surprised me because I even took goldfish and koi as the greatest aquaria hogs but not poecilids at all. Poecilids holded all maximuns values for metabolites production. Perhaps it is related to same mechanisms that make a 1kg of small fishes consume more oxygen than 1kg of large fishes, it is something related to the increased metabolic rates in small living beings. Also Ng et al. (1983)   expressed the metabolic production as mg of metabolite per kg of fish per percent feed per day (mg metabile/kg fish/% feed/day) and since 1kg of fish fed 1% body weight daily will eat 10g I adapted their unit to mg of metabolite per g of feed (mg/g feed). 

Table 2 - Metabolite Production Rates of Various Ornamental Fishes (mg metabolite/g feed).

Adapted from Ng et al. (1983) .