Group study - Optimizing discus growth

[Argentum]

Hello everyone,

Note: it is not the intention of this thread to discus the presence, absence or effect of of the so called GLH. The objective is to design a systematic study to test different variables that contribute to the growth of fish in general and come up with the best practice to do so.

I recently revived an old thread about GLH, and after reading several ones. And a point was raised several times that Discus had not been researched in an extensive way like other farming species where there is money ie: Tilapia, salmon ... etc.

So why not do it our selves, it is very difficult for one individual to do it on his own, however combined we can work it out.
Many of us have multiple tanks, breeding tanks and grow out tanks, an most importantly breeding pairs.

Why do we need to do so?

There are many reasons, it can save us money, time and effort we spend on growing out discus to get them to the large sizes.

What are the factors that we need to study?
There are many factors and to study the effect of one of theses factors all other factors should be fixed.
Important points that need to be studied are:
1- Stocking density
2- Amount of food (usually measured in % of weight)
3- Amount of water to be changed
4- Water temperature
5- Illumination time
6- Diet composition
7- Other factors ... you can suggest

Who can do it?
An one who has the resources and is willing to commit for a 3 months period recording and sharing his findings.

How will the experiment be designed?

In every study all the above factors should have a default value that will be agreed on. Then only the variable that is being studied should be changed. The study should be applied on a single group of discus from the same batch & parents. divided randomly into 3 or 4 groups (depending on how many different values you are going to test)

An example
Lets say we are studying the illumination time, and you want to see the effect of zero, 12, 18 & 24 hours of illumination per day.

So you will get a batch of fry divide them into 4 groups lets say 15 each (the larger the better), feed them 4 times daily, change 25% of the water daily, using only one type of food at 28 C.

The rate of growth will be measured at a set frequency for a period of three months and then statistical tools will be used to evaluate the results. It is best to repeat the same experiment 3 times to get a measure of the RSD.

So who is in? What are your thoughts?

[Argentum]

One more thing I want to add is, the layout I laid for the study is just provisional, and is for discussion.

[kris2341]

This kind of experiment is difficult to do outside of a single roof for a few reasons...

Each person involved probably has different tap water conditions that will affect the results.

As far as stocking, density aside, all tests need to use fish that are as similar as possible, so essentially a single large batch of fry would need to be split among the participants, difficult to do really.

Food mixes also are an issue because no single batch of food is the same really.

But, I can pretty much tell where the results would wind up going... Given that the tanks of fish are practically the same, the tank that is fed the most and has the most frequent 100% water changes daily will win, followed closely by the tank that is fed half as much with the same frequency of water changes as power feeding dives deep into the land of diminishing returns.

Temperature may play a small factor in the metabolism, but if the fish are already eating huge amounts, this is probably negligible and should not exceed 86F for risk of fish getting sick.

There was a grow out contest somewhere here before, i believe that's where much info was obtained.

[nc0gnet0]

There are many reasons, it can save us money, time and effort

Any system that would do so would be wrought with compromises, it is after all, the time and effort that will ultimately make the biggest impact.

[nc0gnet0]

3 months is not an adequate amount of time.

[Argentum]

This kind of experiment is difficult to do outside of a single roof for a few reasons...

Each person involved probably has different tap water conditions that will affect the results.

As far as stocking, density aside, all tests need to use fish that are as similar as possible, so essentially a single large batch of fry would need to be split among the participants, difficult to do really.

Food mixes also are an issue because no single batch of food is the same really.

But, I can pretty much tell where the results would wind up going... Given that the tanks of fish are practically the same, the tank that is fed the most and has the most frequent 100% water changes daily will win, followed closely by the tank that is fed half as much with the same frequency of water changes as power feeding dives deep into the land of diminishing returns.

Temperature may play a small factor in the metabolism, but if the fish are already eating huge amounts, this is probably negligible and should not exceed 86F for risk of fish getting sick.

There was a grow out contest somewhere here before, i believe that's where much info was obtained.

I agree with you that the tank receiving the most WC and most feeding will most probably have the best outcome, however when conducting such studies there is a certain point where the rate of growth will reach a maximum and further increase in the variable will not yield any increase in growth.

This is the point we are trying to identify. by doing this no extra wasted effort shall be spent. I say wasted because extra food water change water volume beyond that point will give no return in fish growth

[nc0gnet0]

I really hate to bust your bubble, and there is nothing wrong with a good experiment, but I feel you may be better served by simply polling the people here that routinely breed good quality large fish, asking them there methods etc etc. All of these will have played with or tweaked many of the questions you have asked.

To partake in your experiment would mean sacrificing large portions of batches of fry, subjecting them to substandard conditions, and ending up with sub quality fish.

[Argentum]

3 months is not an adequate amount of time.

I suggested this a random number based on its repetition in several tilapia publications, What time frame do you thing is more effective?

But keep in mind that at this stage of a study, you are optimizing. After we obtain these optimum parameters it will open the door to get more insight on different methods of growing discus.

For instance, effect of size segregation on the growth under optimum parameters or the change in the rate of growth at different ages when using these optimum parameters.

I am not new to using the scientific method I worked in several analytical chemistry research projects, and is working at the moment developing analytical methods for a petrochemical QC lab. I am not implying that everything I say is correct just saying that I am familiar with designing experiments.

So trust me it can be done. And having the fry from different parents when testing different parameters is okay since they in that particular experiment are a fixed parameter.

[Argentum]

I really hate to bust your bubble, and there is nothing wrong with a good experiment, but I feel you may be better served by simply polling the people here that routinely breed good quality large fish, asking them there methods etc etc. All of these will have played with or tweaked many of the questions you have asked.

To partake in your experiment would mean sacrificing large portions of batches of fry, subjecting them to substandard conditions, and ending up with sub quality fish.

This is true, and it's a price that I believe it is worth it.

If those people are willing to share their tips and tricks, I am here to learn. However, I believe you agree that things are different when approached in a systematic way. Because those people often will have avoided to try some things out of speculation thinking that it may stunt their fish

[nc0gnet0]

Discus growth will typically take more than a year, with your experiment which period are you targeting, and how will you know at the end of three months, that what appears to have been a success at that stage, might not in fact be a reason for the end result (after 15 months) being a substandard fish?

[Argentum]

Discus growth will typically take more than a year, with your experiment which period are you targeting, and how will you know at the end of three months, that what appears to have been a success at that stage, might not in fact be a reason for the end result (after 15 months) being a subs sure whtandard fish?

I am not quiet sure at what stage should the experiment start, as with discus having a complex parenting behavior which will vary depending on the pair them self. Maybe after reaching 2 cm size being fed Artemia the period before that.Then start feeding a BH mix including the same ingredients with the beginning of the study. What do you think?

And your second point is very valid, but I don't know if it's possible to have a set of conditions that will work for juvies but not for adults.
I think these are the things we are going to discover. What do you thing again?

[nc0gnet0]

What do I think? I think raising discus is more of an art form than it is a science. Parameters are constantly changing, and each scenario needs it's own tweaks. What works for one person may not work for the next. People will look at your results and only incorporate the easy stuff, most often with disastrous results. For instance, you might decide that feeding 3" fish 6x a day and doing 5x water changes of 85% or better is the ultimate.

And what will people take from this? Feed discus 6x a day.....but will they do the required water changes? Hell no. Welcome to the world of human nature, were everyone wants instant, easy results, and are not prepared to put the time in to achieve it.

End result-dead or sickly fish.

I will share with you what I have learned. Growing out discus is not a race, it's a passion. The ABSOLUTE most important parameter is clean water and lots of it. Tailor your feeding schedule around your water changes, and adjust how much you feed accordingly. I might feed one amount on weekdays do to time constraints, and increase this amount on weekends when I can change more water. I may adjust what I feed one day when I know my time might be limited, etc etc.

I could care less if my discus at 6 months are 4" or 6", what I care about is how they look at the end of their growth cycle, and if they have reached their full potential.

[Rudustin]

I could care less if my discus at 6 months are 4" or 6", what I care about is how they look at the end of their growth cycle, and if they have reached their full potential. I so agree with this statement.

[Argentum]

And what will people take from this? Feed discus 6x a day.....but will they do the required water changes? Hell no. Welcome to the world of human nature, were everyone wants instant, easy results, and are not prepared to put the time in to achieve it.

End result-dead or sickly fish. .

They should learn the hard way then, thats what happens when you apply half the advice



I will share with you what I have learned. Growing out discus is not a race, it's a passion. The ABSOLUTE most important parameter is clean water and lots of it. Tailor your feeding schedule around your water changes, and adjust how much you feed accordingly. I might feed one amount on weekdays do to time constraints, and increase this amount on weekends when I can change more water. I may adjust what I feed one day when I know my time might be limited, etc etc.

I could care less if my discus at 6 months are 4" or 6", what I care about is how they look at the end of their growth cycle, and if they have reached their full potential.

Thank you for sharing :) thats what I am doing which I learned from you from previous discussions

I still need to conduct these studies, they might be a way to the ultimately best Discus at the end of their growth cycle.... but we just don't know it because it's outside of our comfort zone.

I feel I am determined to start experimenting with this, if anyone want's to share he's most welcome

[timmy82]

What do I think? I think raising discus is more of an art form than it is a science. Parameters are constantly changing, and each scenario needs it's own tweaks. What works for one person may not work for the next. People will look at your results and only incorporate the easy stuff, most often with disastrous results. For instance, you might decide that feeding 3" fish 6x a day and doing 5x water changes of 85% or better is the ultimate.

And what will people take from this? Feed discus 6x a day.....but will they do the required water changes? Hell no. Welcome to the world of human nature, were everyone wants instant, easy results, and are not prepared to put the time in to achieve it.

End result-dead or sickly fish.

I will share with you what I have learned. Growing out discus is not a race, it's a passion. The ABSOLUTE most important parameter is clean water and lots of it. Tailor your feeding schedule around your water changes, and adjust how much you feed accordingly. I might feed one amount on weekdays do to time constraints, and increase this amount on weekends when I can change more water. I may adjust what I feed one day when I know my time might be limited, etc etc.

I could care less if my discus at 6 months are 4" or 6", what I care about is how they look at the end of their growth cycle, and if they have reached their full potential.

Alot of truths here thanks Rick.
It would be more viable to take this to the breeding farms ect in Asia and pool some results that way. There are so many varriables in a hobbiest scheme of things and not everyone is prepaired to be truthful in their documentation.
My routine varries depending on my full time job work load too. Clean water and good food I seem to get fry to 3" in 3 months and 6" in 12 - 16 months. But saying that I have an F1 snow leopard that is 11 months and 6" last time he was out so would be thinking another 6 months should add an inch or two? Time will tell.

[pastry]

I like the idea. I agree with everything Rick says, but I'm never against seeing others experimenting. Maybe just don't experiment with the water changes or amount of food.

It would require a crazy amount of time and resources for an actual controlled experiment but I still enjoy reading about informal, uncontrolled experiments on here where I can draw my own conclusions. It's not "proper" but I still enjoy reading.

[dialysis mike]

Wondering if it would help or hurt to use protein powder in food .such as whey protein like body builders do?or would it have to be added to water directly? Just how would it be used???

[CliffsDiscus]

Wondering if it would help or hurt to use protein powder in food .such as whey protein like body builders do?or would it have to be added to water directly? Just how would it be used???

I have added egg white powder to beefheart before.

Cliff

[Luke in Phoenix]

I think it's a great idea and would love to read about the posted results. There may not be the need for tons of experiments. Just take the consensus of what works best and tweak it from there.
I would also be interested in seeing where the point of diminishing returns are for water changes. Many people agree that power feeding has diminishing returns. How about Water changes? For example, it would be interesting to see the results and difference between 100% daily and 100% weekly WC.