Will BB with 80% WC 3x/wk stunt 3 inchers?

[Michael A]

Is it possible to do 80% 3x/week WCs in a BB without stunting 3" fish?

absolutely, I change 90% 3x/week with no prob

[Oxboy]

absolutely, I change 90% 3x/week with no prob

By "no prob", you mean you don't get any stunted fish with your schedule?

I know 90% 3x/week is just fine for an adults-only tank or for Avg Joe enthusiast who doesn't want to raise award-winning 8-inchers. But does it keep juvis from stunting at that critical 3-3.5" window? Will your schedule produce 6.5 to 7 inchers?

[SpeedDiscus]

If you are looking at an EXACT # or % you must change to not stunt your fish you will be searching for a long time. There are too many variable (fish genetics, food type, feeding frequency, tank size, group size etc) for someone to give you an EXACT # to follow religiously that will 100% GUARNTEE you success.

My group of 8 4-4.5" in a 75 gallonget a 30-50% WC every single day. When they were smaller in their 35 gallon grow out I did 50-80% WC every single day.

[Oxboy]

If you are looking at an EXACT # or % you must change to not stunt your fish you will be searching for a long time. There are too many variable (fish genetics, food type, feeding frequency, tank size, group size etc) for someone to give you an EXACT # to follow religiously that will 100% GUARNTEE you success.

My group of 8 4-4.5" in a 75 gallonget a 30-50% WC every single day. When they were smaller in their 35 gallon grow out I did 50-80% WC every single day.

And on this routine, none of them stunted?

[number1sixerfan]

As many have mentioned, there are a lot of variables involved. The most important being how many fish per gallon of water/how large of a tank, how often you feed, what you feed and how much you feed, and tank filtration. The less water changes you do, the more important each of those become. For smaller discus, which I have raised quite a lot of (but certainly nothing close to that of a breeder or anything), I did every other day WCs. No stunting or issues, but that was also with multiple filters on tanks (multiple sponge filters, two canisters with purigen/chemipure) and not going to heavy on beef heart feedings. Imo if you're going to feed beef heart daily in hopes of maximum growth then I absolutely would stick to daily changes.

For smaller discus, because of how often you need to feed, I probably wouldn't go beyond every other day routinely. And certainly not beyond 3 days more than rarely. But you have to accept that with less water changes there's potentially, slightly more risk of fish being stressed, becoming sick.. and that risk exponentially increases if you don't have experience. Again, not an issue if you know what you're doing and if the WCs are still pretty frequent. No one can estimate what will work for you and your fish, experimentation under your own acceptable risk tolerance is the only way.

[smsimcik]

I'm not looking to cut corners. I am not even talking about illnesses. What I AM looking for is the magical stunt/no stunt cutoff in terms of WC % and frequency. Assuming ten 3" fish in a 75 with a moderate (not heavy, not light, say 4x/day no BH) feeding schedule, I gather that a 50% WC daily will not stunt the majority of them. All things being equal, if you drop the WC sched to 50% 4x/wk, will you stunt the majority of them?

Ok, I'll take a stab at trying to explain this. First off, I've grown out literally hundreds of juvie discus over the years. Some I bought, some I bred myself. So I have experience.

In your set up, if you do 50% or greater water changes/day, none of the fish will be stunted. You will have some that don't grow as big, but that's because they are genetic runts, not stunts.
If you do 50% water changes 3-4x/wk, all of the fish will be stunted to some degree. I guess it depends on your definition of stunted. But none of them will reach their full genetic potential.
Instead of a tank of 6-7" discus at one year, you'll probably have a tank of 5-5.5" discus at one year. If you are ok with that, then go for it.

I know you said you aren't talking about illness, but you should be. If you do every other day water changes like you say, you will probably be dealing with some disease problems whether you like it or not. Some of the fish will start flashing from gill flukes. Some will develop fin rot. Some will get cloudy eyes. Some will develop white bacterial spots on their fins and tail. They will keep eating and acting ok, but having even minor disease issues will inhibit their growth to some degree. Frequent, large water changes dilute pathogens and decrease disease issues dramatically. It's more of a issue with juvies than it is with adults.

[Oxboy]

Ok, I'll take a stab at trying to explain this. First off, I've grown out literally hundreds of juvie discus over the years. Some I bought, some I bred myself. So I have experience.

In your set up, if you do 50% or greater water changes/day, none of the fish will be stunted. You will have some that don't grow as big, but that's because they are genetic runts, not stunts.
If you do 50% water changes 3-4x/wk, all of the fish will be stunted to some degree. I guess it depends on your definition of stunted. But none of them will reach their full genetic potential.
Instead of a tank of 6-7" discus at one year, you'll probably have a tank of 5-5.5" discus at one year. If you are ok with that, then go for it.

I know you said you aren't talking about illness, but you should be. If you do every other day water changes like you say, you will probably be dealing with some disease problems whether you like it or not. Some of the fish will start flashing from gill flukes. Some will develop fin rot. Some will get cloudy eyes. Some will develop white bacterial spots on their fins and tail. They will keep eating and acting ok, but having even minor disease issues will inhibit their growth to some degree. Frequent, large water changes dilute pathogens and decrease disease issues dramatically. It's more of a issue with juvies than it is with adults.

Exactly the feedback I needed. Thanks.

[number1sixerfan]

Ok, I'll take a stab at trying to explain this. First off, I've grown out literally hundreds of juvie discus over the years. Some I bought, some I bred myself. So I have experience.

In your set up, if you do 50% or greater water changes/day, none of the fish will be stunted. You will have some that don't grow as big, but that's because they are genetic runts, not stunts.
If you do 50% water changes 3-4x/wk, all of the fish will be stunted to some degree. I guess it depends on your definition of stunted. But none of them will reach their full genetic potential.
Instead of a tank of 6-7" discus at one year, you'll probably have a tank of 5-5.5" discus at one year. If you are ok with that, then go for it.

I know you said you aren't talking about illness, but you should be. If you do every other day water changes like you say, you will probably be dealing with some disease problems whether you like it or not. Some of the fish will start flashing from gill flukes. Some will develop fin rot. Some will get cloudy eyes. Some will develop white bacterial spots on their fins and tail. They will keep eating and acting ok, but having even minor disease issues will inhibit their growth to some degree. Frequent, large water changes dilute pathogens and decrease disease issues dramatically. It's more of a issue with juvies than it is with adults.

Exactly the feedback I needed. Thanks.

Not to argue or open a can of worms, but as already mentioned there are just too many variables to be able to reasonably state that "all fish will be stunted" or will have health issues if you don't do daily water changes. That's simply impossible to do. What is possible to do is to test your water quality and adjust variables based on that and how your discus are reacting. Definitely, you have less room for error for sure.

Again, one of the greatest variables which has already been stated a few times is how often you feed. A lot of people feed between 3-6 times a day. Whether you're on the higher or lower end of that greatly will impact water quality. You can maintain better water quality by reducing how often you feed without risk of stunting (so long as still feeding enough). The next is types of foods. The cleaner the food, again same concept, lighter toll on your water quality. There's no way I'd skimp on daily changes if you're feeding something like beef heart or anything that greatly fouls the water frequently.

Fully acknowledging that optimizing for maximum growth in the shortest amount of time is a totally different topic.. and for that reason alone I totally understand why you'd do and strongly recommend daily. Just refuting the absolute statement above.

[Shan_Evolved]

I've done 50% water changes every other day for my batch of 2.5" discus. I fed 3-4 times a day. Weekdays because of work I fed BH twice and granules once. Weekends I fed BH 3 times and granules once.

My group have grown from 2.5" to 4.5+" in 6 months. They are around 8 months old now sitting at 4.5"+. Out of the 11 I grew together, 2 of them are definitely smaller then the batch but that could be due to already being a runt from the batch at 3 months old (time of purchase).

Things to really look for is as follows -

Stable Water Parameters
-Fully Cycled
-Stable non-fluctuating PH
-Age water if needed

Clean Water
-Wipe down tank insides at least once a week to clean slime
-Pat sponge surfaces to make sure water flow is working
-The more you feed, the more often you have to clean your surfaces in the tank

Good Batch to being with
-You can only grow a discus that's already grown well as a baby

Both of these are dependent on feed quality, quantity, and frequency. I also siphon their poop 1-3x a day to help keep tank clean.

[Oxboy]

I've done 50% water changes every other day for my batch of 2.5" discus. I fed 3-4 times a day. Weekdays because of work I fed BH twice and granules once. Weekends I fed BH 3 times and granules once.

My group have grown from 2.5" to 4.5+" in 6 months. They are around 8 months old now sitting at 4.5"+. Out of the 11 I grew together, 2 of them are definitely smaller then the batch but that could be due to already being a runt from the batch at 3 months old (time of purchase).

Things to really look for is as follows -

Stable Water Parameters
-Fully Cycled
-Stable non-fluctuating PH
-Age water if needed

Clean Water
-Wipe down tank insides at least once a week to clean slime
-Pat sponge surfaces to make sure water flow is working
-The more you feed, the more often you have to clean your surfaces in the tank

Good Batch to being with
-You can only grow a discus that's already grown well as a baby

Both of these are dependent on feed quality, quantity, and frequency. I also siphon their poop 1-3x a day to help keep tank clean.

so you are saying there are days when you syphon poop 3 times that day?

[Shan_Evolved]

Sorry late reply but yes. I typically siphon poop as often as I can. When I feed beefheart or granules, it falls down and the discus toss them around everywhere. I've noticed sometimes they accidently eat their own poop and I don't want them risking infection by doing that so I try to minimize as often as I can