has anyone ever tried an experiment like this?

[ewok]

i have been reading a lot about the merits of certain foods over others, and i was wondering if someone has actually done a scientific study along the following lines:

- x number of groups of juvenile grow outs each containing like 6 fish for example, from the same batch each starting out around the same size
- sample of x types of manufactured foods e.g. tetra bits, ocean nutrition flakes, hikari discus bits(?), new life spectrum etc.
- x number of say 50 gallon grow out tanks

the test would be a simple test where you have these batches of juveniles fed only the designated food for that tank. all test parameters - number and volume of water changes is the same, number of daily feeding, same tank layout, filtration, temperature, water parameters etc. would be the same. the idea would be to see if there is a basis that some foods clearly are in fact better than others.
the criteria for defining what is 'better' is obviously size over time for one, but overall health, # of incidents of diet-related diseases, color quality on the fish etc.
thus the purpose is to define whether there is really a basis to say type A food is clearly superior to type B food because of X, Y and Z merits?

we all love our fish a lot no doubt, and i don't want to be seen as some kind of renegade by asking this, but is there truly harm in feeding only one or maybe two types of processed foods :angel:? i myself have like 6 types of flakes, one pellet food and 4 frozen foods, and would see value in knowing information such as this...

thoughts?

[brewmaster15]

Sounds like an awesome experiment.:) You'd have your work cut out though on the number of tanks, time commitment, and cost.

Sadly..no such study has been done that I know of with regards to discus...These studies are done often where theres much money ...as in The Foodfish aquaculture industry.

If one Knows the exact nutritional needs of a fish species and what they find palatable..its possible to grow them out on one food to adult hood as is done in the Food fish industry ...How that single food affects longevity...I have no idea...in that industry..the goal is rapid growth to a marketable and profitable size for human consumption.

I look at my fish from this view ...in the wild, do they eat a mix of food or a monotype food?...Discus have a mixed diet in the wild... We are still learning about what a perfect discus diet is....The mixed diet is away to hedge your bets that you are giving them all they need for maximum growth and longevity.....That may be overkill for a discus's needs...but Its what I do.

hth,
al

[Don Trinko]

Unless you add some zeros on to the number of fish involved the results will not hold up to scientific scrutany. Similar tests have been done with game fish and food fish. The bottom line is :clean water and lots of good food.
This can be a small tank with lots of wc ,good food, and good cleaning or a big tank with less wc, still good food and still good cleaning. Or to say it differently: It's easier to do with a big tank and less fish. Don T.

[William Palumbo]

I remember when I first started with discus in the mid 80's. In Chicago was a LFS that bred and sold them. Was the ONLY store like this in my area. His name was Charles Glut. I knew nothing about discus...saw them for the first time and bought two on the spot not knowing anything about them, and did not ask.. Got them home and I liked them. Then I got four more. Were the most expensive fish I had bought. Long story short, I finally put those 6 discus in a 30 extra high tank. They were juvies. I fed them only a beefheart mix that he sold from his shop. I have no idea what was in it other than beefheart, which at the time to me I never heard of! I fed it to them twice a day...for over 8 years! I changed 75% of the water every Sunday. The fish grew well and were big. They were in a decorated tank, where they stayed for their 8+ years before reluctantly getting rid of them . Fed only two times a day with one type of food, and a weekly water change, was without a doubt the EASIEST tank of fish I ever owned. I always missed those fish. They taught me how easy discus could be by meeting a few basic needs.... Later on down the road when I THOUGHT I "knew" everything about them, I chose to complicate things and make it more work than it has to be....Bill

[brewmaster15]

Bill,
What do you feed now?

-al

[William Palumbo]

Al....as most on here, I still feed a BH blend that I make, FBW and tetra bits. I was feeding the live CBW but were too $$$ for the growing number of fish I have now..Plus the worms were not always in when I needed them. I do feel all living things, especially captive ones, need a variety in their diet. Logic tells us that this to be true. But is it? Those first discus I grew out over 20 years ago, with a min. of feeding and water changes, were as big as most of my adults that I have now...who get daily waterchanges and fed 4-5 times a day a variety of foods. I have noticed over the years when I tried to get away from the mess of beefheart...the making and the tank cleaning...and only feeding flakes or bits, and FBW the fish did not really do as well as the ones fed the beefheart. I know there is high protein in flakes and bits...don't recall the amount of protein in FBW. But even with all that protien...there is no "beef" or heft to the food. I feel discus need that bulk that can't come from flakes or FBW. Defrost a cube of FBW and the same size cube of beefheart...and tell me which one is a gut-load. FBW is A LOT of water! I know beefheart is messy in the tank...even when made properly...which was why I tried to get away from it. I know it's full of "hormones" that make fish sterile(don't tell that to my pairs who were successfully spawning!) I do use veal hearts as there is less fat to trim meaning less waste...Bill

[brewmaster15]

LOl Bill....Yep...I agree on all accounts...been there and done as you.:)

-al

[ashaysathe]

This is one of the readings Bill that after which you really feel you have read something nice.. and I liked they way you have expressed your experience. Very nice. I wouldn't even go for a conclusion on this.. very very nice indeed

[William Palumbo]

Hi...yes BH does give discus that extra "oomph!"...is it the be all end all?...I doubt it. I would feel the best diet would probly consist of mostly live foods such as various types of worms, live insects and insect larvae, such as mosquito and midge larvae to name a few. That diet alone grows some very big wild trout! I grew some nice fish on just live CBW, but that was just too expensive to do in the long run. For what I was paying for CBW a week...I knew that I was breeding the wrong thing...I should of been breeding CBW...is where the money is at! But for the average discus keeper or small breeder I would recommend at least one feeding of a BH mix daily. I tried in the past to make a BH mix...without the beefhearts. Using just shrimp, various fillets of fish, some vegetables and fruit mixed together. Turned out to be VERY messy to make and too messy for the tanks. I'll just stick to what works for me...and the beefheart is fine for now. To raise a discus properly takes about a years worth of work. Not easy. Not cheap. To have fish on hand to experiment with is no problem for those of us lucky enough to breed. But to INVEST over a year into a tank of fish that may or may not pay off is to me not worth it. Our time is valuable to us, and running tanks do cost money. Probally why there are not too many experiments done out there....Bill

[Dkarc@Aol.com]

I have found a few research papers that give specific numbers for optimal nutrition/growth for discus. Protein: 45-50%, Lipid: 8-10%, with fiber and ash minimal as possible. I can find a pelleted food that is commercially available pretty easily with those numbers. The biggest problem is finding a pellet food that is highly palatable for discus at all sizes. I think that a big key to being able to use a single type of food is not only it being nutritionally complete, but it must be accepted easily. If they dont eat it, they dont get the nutrition which will affect the fish as a whole.

On the other hand, if your water quality/parameters are not up to par, nutrition means squat. Water quality is a MUST. Without proper conditions met in the water, the fish will suffer. Personally, I think that water quality plays more of a role in growth of a fish. Health is most definetly affected by water quality. And I will say that water changes are NOT the only way to maintain optimal water quality. I strongly believe (and im sure Al knows now as well) that there are other ways to maintain water quality without the massive water changes. That is a whole other subject though.

-Ryan

[brewmaster15]

I strongly believe (and im sure Al knows now as well) that there are other ways to maintain water quality without the massive water changes. That is a whole other subject though. Yep.:):)

-al

[gotfish?]

please do share...:D

[ewok]

hehe seems like this is not going to happen :)
i know i don't have the time or space to do this... but it would be nice to really see how beneficial certain foods may be (all things being equal of course) over others.
i guess i will stick with what i have for now :)

[Dkarc@Aol.com]

please do share...:D
In a nut shell.....its all about how to properly manage and maintain the water through various methods of mechanical, biological and chemical filtration.....as well as knowing how to do so properly. There are entire companies out there who do nothing but devote their entire businesss to designing, building, and experimenting with various forms of commercial filtration systems/methods. If you really want to know how to do it, I highly suggest in reading on all aspects of commercial fish farming (filtration, monitoring, loading rates, etc). It is far to technical or in depth for me to even touch on....let alone for me to even know part of it. Im sure members like Graham and a few others would know what im talking about. There are several good books out there that you can find easily that are great resources. Aquatic Eco Systems is one company who has a great list of books available.

-Ryan

[William Palumbo]

In a nut shell.....its all about how to properly manage and maintain the water through various methods of mechanical, biological and chemical filtration.....as well as knowing how to do so properly. There are entire companies out there who do nothing but devote their entire businesss to designing, building, and experimenting with various forms of commercial filtration systems/methods. If you really want to know how to do it, I highly suggest in reading on all aspects of commercial fish farming (filtration, monitoring, loading rates, etc). It is far to technical or in depth for me to even touch on....let alone for me to even know part of it. Im sure members like Graham and a few others would know what im talking about. There are several good books out there that you can find easily that are great resources. Aquatic Eco Systems is one company who has a great list of books available.

-Ryan

Ryan...can any of this be done by the average hobbyist or small time breeders that visit this forum? What I gather from what I have read so far sounds to be something large scale and very expensive. I don't think it's something I or others here could employ. I know in my older discus literature in Germany they were trying to get away from the large water changes and waste RO water using certain plants and a boatload of resins. I have no doubt about what can be done to water...especially on a large scale such as commercial fish farming and even municipal water treating plants where they take waste water and turn it into drinking water. That's A LOT of specialized and very expensive commercial equipment. What can I do, as well as others, on a smaller scale to reduce our water changes, both in frequency and volume?...Bill

[Ed13]

Bill, it can be done by a hobbyists, however most of the research is done by or for large corporations and most of what they come up is just not cost effective to employ or purchase by a hobbyist. Having said that, the principles they come up with can be understood and applied by many of the smart and ingenious hobbyists out there. We also need to filter out what works and is beneficial to the fish from what works or not.
I know that controlling levels of dissolved oxygen have been used infish farming to controll size, or so claimed the farm's employee:D
I am curious on what Graham has to say and I wonder if Al learned any inside tip when he visited that trout farm,.

BTW, kind of topics that might have a hand in the future of the hobby itself, so if you have any ideas in the matter bring them to the table.

[ShinShin]

Bill,

When you said that those fish years ago were almost as big as the ones you have now, how big are we talking in SL?

================================================== =====================


Genetics is another factor that has to be included in the equation. There are lines of discus out there that it doesn't matter how much water you change, or how much of whatever you feed, you won't get 6-7"SL discus from them.

Maybe Al or another can find it if they feel like looking in the archives, an article that was based on scientic research about growth and food. It was some years back, and who knows, it may have even been on JQ's forum. Who can remember after all these years and so many different forums many of us frequented. I know it was after Yeng published his book, because I remember he was correct when he said discus require 50% protein foods. I found a scientific formula that allowed one to calculate this percentage based on certain factors. Fat content was more important than higher levels of protein for growth. 50% protein and 12% fat produced larger fish than protein percentages of 65-70% and 4% fat.

I think it would totally impossible for the average hobbyist to use scientific method to undertake this project. At best, all most of us can do is observe over years of experience, trial and error, what works and what doesn't. I have performed many experiments on growth using water changes, food and temp as factors. None were performed by scientic method. No control group was used. Some observations I noted were that 86F water temp didn't produce larger growouts from the same spawn than 84F fed the same diet and same water change, in general. The more water change, more often produced larger discus from the same spawn, in general. Salmon was as good as BH when all else was equal in the mix, temp, and water change, in general. Quality pellets and flake produced the same results as pellet, flake, and FBW's, in general. Amino acid precursors to growth hormone found at any health and nutrition center, when added to a frozen BH or salmon mix will produce deformed pectoral fins and anal and dorsal fins similar to angelfish. This one was difficult because I had to attemt to convert the human dosage based on weight, to a discus. I probabally used too much.I dumped the spawn and amino acid bottle and made no more attempts at this experiment. Over the past years, I have performed other tests. All were done to satisfy myself only, and I used my observations against statements made by others concerning the topic.

Mat

[William Palumbo]

Larry...those fish I talked about when I first started were never measured with a ruler...but their body were all a bit bigger than my hand...not including finnage. I would guess over 7". It was also from wild blood-lines. I agree with genetics being a big factor in growth. I am raising up a spawn from a Bluediamond and cobalt pair. It is not my pair, but I purchased 18 juvies from a local breeder. In the tank the fry varied by pattern and coloration. I picked out 6 striated ones...6 fully colored ones....6 bluediamonds all from the same spawn. Each strain recieved it's own 55 gal tank. With the feedings and waterchanges being equal...the bluediamonds are a good 1/3 bigger, vastly outgrowing their siblings. Many years back I bought some giant red turks from Lo Wing Yat thru Marc weiss...Those fish seemed to grow by the minute!...where as I bought some Manfred Gobel giant cobalts...that just stayed dwarfed...never got any size to them. I guess as seasoned hobbyist, we just pretty much stick to what works...as it took many years to get there...Bill

[BSW]

I'm just a dummy I guess !
I bought 10 juvies that came from Forrest ( I now have 15) grew them out in a planted 60 (a no no, I know, wouldn't do it again)
killed my plants three times !! Gave them all the frozen brine shrimp they would eat, plus several high quality, high protein dry foods. Never really analyzed the food, just tried to get the highest protein I could. Never fed worms (but I'll bet they wish I would) 50% water change every other day (still do). Vacuumed three times a week, wiped the glass, all that. But I think if you buy good fish and give them good care, all will do well. They are now all 7"+
Good food and good fish make a HUGE difference, I'm no "Discus Pro" If I could do it any one could !
Good food makes a difference (no doubt) but, so does good stock.
http://i148.photobucket.com/albums/s12/rlwbsw/Discus23010.jpg
Just MHO
BSW

[ewok]

BSW - great looking fish :)

i agree this kind of experiment wouldn't be an easy endeavor - was just trying to put some basis behind the discussions :)
hehe

[BSW]

Thanks -
they are my big pets -
But your right -
For those breeding or growing out fry, I can certainly see the importance.
And I'm sure there are many things that make difference !!! It's worth totally looking into ! For the average Joe, like me, I just fed them the best I could, they've eaten everything from table shrimp to Lobster, to Roast Beef, if you can believe it ! Not their normal diet though ! I think I could throw dynamite in there and they would eat it !! What goobers !
BSW

[William Palumbo]

Nice fish BSW!...I agree 100% that good stock makes a difference. Your fish look great...and whatever your methods...are working for you. No such thing as a discus expert!...lol...just some of us with more experience than others. I think one very important factor is, when fish are sold they are usually sold at the min. 2-3 inch mark. I feel the care and feedings...frequency and food types that are fed to get those discus to that size is a VERY critical period on discus development. In my experience, during that time period getting the fish to a salable size, any groups of fish that were not fed well or good eaters, usually never reached full potential compared to their siblings. Which is why when hobbyists recieve these fish at this size, it is critical they feed these fish often....and change lots of water to stimulate growth. Discus grow in spurts. When young we can see them grow like weeds, then at a certain age the rapid growing seem to slow or stop, only later to spurt up again. We just have to make sure we can do all we can to give them the most, so they can utilize these growth spurts to their full potential....Bill

[BSW]

Thanks William -
My only pitiful little method is that the little hogs get to eat before I do !
But good food is sure worth looking into, I'm doing more reading on that topic myself, and I appreciate reading all you guy's info !
BSW

[William Palumbo]

BSW..don't feel bad...my fish eat better than me!...Just bought 10 pounds of shrimp for the beefheart I will be making Sunday. I was spending $20 for a pound of blackworms, when even I don't eat anything that's $20 a pound!...Bill

[ShinShin]

Thanks, Bill. I am amazed at how I kept my first two pair of wild discus way back when, breaking every rule known to the discus keeper, and they survived for two years before I got rid of them.

Mat