Discus growth / Tank size

[bernie82]

It's been a common belief among fishkeepers that fish need adequate space to grow to their full potential. It is also believed that surface area (length x widith) is the major factor and that tank depth is not nearly so important.
I'd like to open the following "what if" for discussion. Assuming 50% daily water changes and great food and frequent feedings in all the following wxamples..
If I put six 2.5 inch Discus in a thirty gallon tank, do you think they could grow to the full potential?
If you said "no' then what if I put six 2.5 inch Discus in a 60 gallon tank and partitioned the tank (flow thru partition) in half and put all the fish in one side of the partition? Even though they are restricted to only 30 gallons of tank space, they are in a 60 gallon tank. Do you think they would grow to their full potential?
If you said "yes" then does that mean we are far better off to divide our growout tanks in half so we can keep twice as many fish in them and still bring those fish to their full potential?

[Carol_Roberts]

Discus grow just like children. A shoe that fits a four year old is too small for a fourteen year old. would you make a fourteen year old continue to wear a four year olds shoe?

If you can only have one tank get the 60, start with a partition, but you will remove the partition after a couple of months so they have the full tank to swim in

[bernie82]

Hi Carol. Thanks for the response. You completely missed my point. Basically my question is "Is a divided 60 gallon tank capable of supporting substancially more fish than two 30 gallon tanks."
And to answer your question, Yes, I would. Lol.

[JeffreyRichard]

Interesting discussion ... while there is a point that water change volume does not not dilute the toxins in the tank, for the purposes of this discussion one can assume a daily 50% water change would provide enough dilution to eliminate toxins as a variable.For the sake of argument, you could up it to 100% water change daily ...

Assuming the above statement, putting the fish in a 60 gallon tank that is partitioned in 1/2 will not affect the fish at all. Nor would putting the fish in a 120 gallon tank partitioned into quarters. In fact if you had a rectangular box made out of netting and this was the same size as a 30 gallon tank, filled it with fish and floated it on the Amazon river, you would not affect the growth over the same 30 gallon tank ... assuming equivalent water quality.

[Jeff]

If I understand what you are asking I think you are asking if I over crowd discus, but give them the proper nutrition, and water changes will they still grow. From my experiance YES. In fact they will grow faster. The key is water changes. More than 100% a day. I have done this just to see for myself. I usually stop at around 3-3.5". I have not tried to grow them to adults and see what the final result is. I have put 12 1" size in a 20 and 12 in a 40 from the same spawn and given them both the same amount of feedings and the 12 in the 20 grew faster to 3". The 12 in the 20 I did 95% wc 2x a day. The 40 I did 50% once a day. I stoped when they hit 3-3.5". I have done it twice and think I could repeate it again.

[bernie82]

Hi Jeff. so with your example of putting the fish in a 30 gallon mesh container and floating the comtainer in
the Amazon river would not give the fish the benefit of great water and enormous surface area and their growth we be impaired becuse of the size of the container that they are restricted to. If you believe that, then you belive that the reason they won't grow to full potential is because they don't have enough freedom of movement. Think about it Jeff.

[Jeff]

Well as I said I have only taken them to 3-3.5". I do not believe freedom of movement impars their growth to that point based on my observations. Just my guess, but I believe it to be more the enviroment (water conditions and food). Two experiments are not that many and it would have to be done more times than that and to full growth before much can be conculded. I just thought it was interesting. If you have the time and discus maybe you can try a few things and let us know.

[April]

well....id think the benefit of more water volume cant hurt ...if you ahve them partitioned in a 60 gallon tank. they do eat better in a big group. far more competitive.
i right now have 6 little fry in a 40 gallon tank. they nibble all day.never without food and they are not growing faster. if anything their behind. and im also doing about 50 percent change a day. im sure if i had a big group of fry they would all be competing and eating more aggressively. and im sure theyd feel more secure. on the other hand....ive heard people who have big tanks get their fish very big..and are only doing 25 percent change a day . of course it could be the different diets.
i have no idea about discus but i have a coffee shop in town who has about a 20 gallon tank . and in it he has a koi. well the koi is over a year and a half old..and its still only about 3 inches. looks healthy etc. but small. i got koi not long ago...the beginning of summer, or late spring...and they are now over 6 inches. mine are in a 70 gallon tank. will they grow as big as the ones in a big pond? not sure on that...theyd have trouble turning around. lol. of course carp and discus are hardly alike.
i think a good experiment would be to have a 20 gallon tank with rapid water replacement. constant water running in and out. so all new water all the time. see how fast they grow. still small area.but tons of clean water and food.

[CARY_GLdiscus]

IME they grow faster in smaller tanks if you can keep up with all the work!


w/c w/c w/c w/c + food food food

[Teitelbaum]

I bought an unproven 6" breeding pair from a friend who grew them up in a 30 gallon tank with at least 20 adults in there. I saw them grew up and eventually start pairing and laying eggs in the same tank. The breeder has a constant drip system dripping 300% a day.
Earl.

[John_Nicholson]

Cary is 100% correct. If you can do the work you will get the best growth in small tanks. I have never really tried to figure out exactly why. I just know it works.

-john

[JeffreyRichard]

Hi Jeff. so with your example of putting the fish in a 30 gallon mesh container and floating the comtainer in
the Amazon river would not give the fish the benefit of great water and enormous surface area and their growth we be impaired becuse of the size of the container that they are restricted to. If you believe that, then you belive that the reason they won't grow to full potential is because they don't have enough freedom of movement. Think about it Jeff.


In the hypothetical case, I stated that water quality wasn't a facter (water in the 30 gallon tank = water quality in the mess container). You would not see any benefit to surface area of the water outside the mess container. So you would in effect have a 30 gallon tank set up for the discus floating in the river. Practically speaking, one probably couldn't approach the water quality of an open river in any closed system unless you had a continous flow of fresh ater into the closed system and an outflow of waste water. So in fact water quality of the system which uses the bigger holding arrangement, whether it's a 60, 120 gallon tank or a river, would be better off than the smaller tank.

My point is there is no derived benefit of partitioning off a larger system over using the smaller system, other than water quality. They both have the save effective area for hold the fish.

[knobby]

someone should try putting 10 discus in a drilled 29

then plumb that 29 into a 125 gallon sump

best of both worlds lol
large volume of water for water quality and stability
and a smaller space to encourage feeding and growth

;D

[ks]

i have noted significant growth when my discus move to a bigger thank,

iniitially i grow 4 2"OG in a 20 gal tank, they grow pretty slow to 3". i then moved them to a 40gal tank togather with another 4 SW (ideally i would want 50gal) and noted they have grow to 4" in one month ;D, w.c was still 25% daily, 4 meal a day. i believe they need adequate space for movement.

[John_Nicholson]

ks discus historically don't do well in numbers as low as 4. That may have had an affect. Also when I growout large numbers of fry in 29 gallon tanks (100+ fry) I try to change 50% of the water twice a day.

-john

[wyang76]

I think the more room a fish has, the bigger it will grow. Which is why wild discus are larger than domestic ones.

Given that water quality is excellent and consistent. It all comes down to the amount of food given in A CERTAIN AMOUNT OF TIME and growing space.

6 - 2" discus in a 30 gallon vs. 6 - 2" discus in a 60 gallon

Given that you feed them EXACTLY the same amount, the 30 gallon will grow faster because the discus are consuming the food in a shorter amount of time because space is smaller. In a 60 gallon, the fishes have a harder time consuming all that food in the same amount of time.

In other words, i would grow faster eating 1 - 20oz steak every 6 hours vs. 1 -20 oz steak every 10 hours.

However, if the 60 gallon fishes were able to consume the EXACT same amount of food at the same time, the fishes WILL grow larger than those of the 30 gallon.

The reason? More room to move and swim and explore. Fishes have muscles also. It is like a kid going through puberty and playing sports, it will help the kid grow faster. Muscles do grow and stimulate.

That is why Wild Discus are larger. Wild Discus are scavengers, always searching and eating, picking things off the river bed, constantly eating, and always moving. It's like eat, poop, swim , eat, poop, swim.. Swimming is like working out. That is an excellent growth model.

Let's go back to the 30 and 60 gallon tank.

If you partitioned the 60 gallon tank in half and slowly moved the partition to accomodate more space for the discus, i am sure it will grow faster than the 30 gallon. However, in order for this to work, the partition cannot be moved in which it will AFFECT the food consumption rate of the larger tank. Both tanks must still be able to eat the same amount of food in the same amount of time.

Those are my thoughts...

I welcome any comments.. and take it easy on me.

[John_Nicholson]

Most of the wilds that I see are not larger then my domestics. In fact most that I have seen are smaller then my domestics.

-john

[wyang76]

I wonder if that may be due to the type of discus in the wild. i have seen some very large wild discus.

I guess it would make sense that domestic discus are large. Because we have the abiltiy to selectively choose which ones to breed.

It's almost like finding the tallest people in the world and having them have kids.

[ks]

ks discus historically don't do well in numbers as low as 4. That may have had an affect. Also when I growout large numbers of fry in 29 gallon tanks (100+ fry) I try to change 50% of the water twice a day.

-john


noted :idea:

[GulfCoastDiscus]

I received some frys over 40- 1" more or less and placed them in a 55 and they were stress and cower on one side of the tank barely verturing. I reduced the water by half and still the same. I placed them in a 20 and seems less stress. I think discus do better in tanks the are relatively proportionate to their size. I keep them in a smaller tank till they seem overcrowded. IMO is like growing cattle or poultry. You give less space to expend their energy and thus more and faster growth. Of course you have to do your water changes deligently. Discus tend to be less stress in a crowded tank because of their schooling instinct. Remember lots wc wc wc JMO

Dan

[Jeff]

Right on Dan. :)

[Shari]

OK My opinion afer growing numerous Discus from the 1 1/2"-2" size......all started (8 Discus) in a 55 gallon together at same size, a year and a few mos. later some were moved to a 120 gallon. Both tanks also rec'd new 2" fish as additions.

In the 55 gallon two are about 7 inches now, in the 120 gallon also three are about 5-6", and the newer kids in both tanks are doing 1/2 and 1/2 - rapid growth in some, slower in others - all receiving the same water changes/feeding etc.

Think it depends on the fish. the w/c's I truly belive the big issue but who gets the most food is foremost from what I see here at home. My pigs are the big ones and my humble shyer ones are smaller cause they don't take a stand for the food.

So I haven't said a thing of importance or told anyone anything..just thought I would mention. Still puzzles me sometimes.... ::) ::)


(and yup - my domestics are same or larger than some of the wilds I've owned)