How many discus in a 40G breeder tank?

[roydooms]

I ordered 5 discus(3.5-4.5") from Kenny and I'm wondering how many discus I can put in this size tank. Also, how many if they become full-grown. Thanks.

[Larry Bugg]

A 40 gallon will be too small for 5 when they get to be adults. Most I think will agree that a 55 is minimum for adults and a 75 is better. You don't want less than 5 adults in a tank or aggression may become a issue and because they are very social that will be happier in larger groups.

[Orange Crush]

I use a 40 breeder for a QT tank but ideally discus should be in tanks that are at least 3' long preferably 4' (could you imagine walking around in small circles your entire life?). Also discus need at least 10 gal each.
I would not keep adults in there and it is a bad idea to have less than 6 discus together (could lead to serious aggression problems).

[roydooms]

Thank you both for the replies :)

I might just end up using this as a grow out tank or a pair tank.

Just one question. Isn't the 40g breeder's footprint[36"L (3')x 18"W] better than the 55's or no?

[Orange Crush]

I had forgotten that the 40 breeder is 3' long; it looks sooo small to me. The footprint of the 40B is better than a 55 but it is just not enough gal for 6 or more discus. 75 gal is better than 40, 50 or 55 gal because of the gal and footprint.

[roydooms]

I had forgotten that the 40 breeder is 3' long; it looks sooo small to me. The footprint of the 40B is better than a 55 but it is just not enough gal for 6 or more discus. 75 gal is better than 40, 50 or 55 gal because of the gal and footprint.


I should have aimed for the 75g tank. I already bought the tank and built a stand. SMH. I should have asked first. Another question. If you calculate the outside dimensions of both tanks (55 and 40B) 55 is only 54g and 40B is really 47g. Will that 7 gallons really make a huge difference? Don't get me wrong and I'm not trying to push that that I can use the 40B. Just some innocent questions. Thanks.

[Orange Crush]

A 40 gal tank only holds 40 gal of water.

[roydooms]

A 40 gal tank only holds 40 gal of water.

That's not true in this case. 40B is 36"x18"x17". Multiply them = 11,016 divided by 231 = 47.68 gallons

[Orange Crush]

(36x18x16)/231= 44.88 but you do not fill it 16" deep since part of that hight is the frame on the outside and you don't fill it to the very top.

[roydooms]

And still it is not only 40g. As for not filling it up 16" deep, isn't that the case with the 55g as well?

[discuspaul]

It's still a good tank to grow out about a half dozen 3" juvies. Then get yourself a larger tank while they're growing out.

[roydooms]

It's still a good tank to grow out about a half dozen 3" juvies. Then get yourself a larger tank while they're growing out.

Hi, Thanks for the reply.

Until what size would you keep the juveniles in this size tank before you move them to larger ones? Thanks.

Roy

[Larry Bugg]

You can't determine the gallons of a tank by measuring the outside dimensions. You have to measure the inside deminsions.

A 40 breeder is one of my favorite tanks but just not for adults.

[roydooms]

You can't determine the gallons of a tank by measuring the outside dimensions. You have to measure the inside deminsions.

A 40 breeder is one of my favorite tanks but just not for adults.

Hey, thanks for the reply.

I agree with you. The only reason I'm basing on the outside dimensions is because I don't know the inside dimensions.

[Larry Bugg]

Hey, thanks for the reply.

I agree with you. The only reason I'm basing on the outside dimensions is because I don't know the inside dimensions.

The problem is you can't do a comparison of two tanks that way. You could have two tanks with identical outside dimensions and the total gallons could be different.

[roydooms]

The problem is you can't do a comparison of two tanks that way. You could have two tanks with identical outside dimensions and the total gallons could be different.

How is that? Thickness of the glass or acrylic?

[roydooms]

Ok. So a 40g breeder is only good as a grow out tank or for a pair(?). I understand that. My question now is, at what size do I need to move the discus to a bigger tank assuming I have 6 in this tank?

[Orange Crush]

The problem is you can't do a comparison of two tanks that way. You could have two tanks with identical outside dimensions and the total gallons could be different.
Yes, like I said earlier, a 40 gal breeder holds 40 gal of water. If it could hold more believe me companies would say that. Would you rather pay $100 for a 40 gal tank when you could pay $100 for a 47.68 gal tank?

[Orange Crush]

Since you just purchased 5 discus(3.5-4.5") I would only keep them in there for 6-8 weeks for QT after that they really need a bigger tank.

[roydooms]

Does a 55g tank holds 55g of water measuring the dimensions from the inside? Can some one measure that for me pls. I just want to see the difference in gallons to a 40B.

[roydooms]

Since you just purchased 5 discus(3.5-4.5") I would only keep them in there for 6-8 weeks for QT after that they really need a bigger tank.

I see. I have a 125 g that has 8 discus. What's the limit # of discus on that one? I add 5 more that'll be 13 total. Is that pushing the limit? Thanks.

[roydooms]

It's a community planted discus tank with tetras(40) and corydoras(15). Out of the 8 in the 125, I have 2 pairs. So, if the 13 total in a 125g is too much with the other fishes, I can move one of the pairs to the 40B after quarantining the new fish.

[Orange Crush]

Does a 55g tank holds 55g of water measuring the dimensions from the inside? Can some one measure that for me pls. I just want to see the difference in gallons to a 40B.
A 10 gal tank hold 10 gal, a 40 gal tank holds 40 gal, a 55 gal tank holds 55 gal. Do you see the pattern here? There is a reason tanks are sold claiming to hold a specific amount of water, it is because they can hold that amount of water.

[roydooms]

I get what you are saying... I will just measure that myself and update you guys. I want to know the exact volume measuring it from the inside.

[roydooms]

Here's an example.. I have a 10g QT tank. I drained 5 gallons and what's left is less than half the tank. Which is less than 5 gallons. That makes the total water volume of the 10g less than 10g. Do you see why I ask these questions?

[roydooms]

To know the exact volume of water in a tank also helps when you are medicating. That you don't overdose.

[Orange Crush]

It's a community planted discus tank with tetras(40) and corydoras(15). Out of the 8 in the 125, I have 2 pairs. So, if the 13 total in a 125g is too much with the other fishes, I can move one of the pairs to the 40B after quarantining the new fish.
A 125 gal can hold 12 discus (they need at least 10 gal each) but when you put substrate, plants, and other decorations like wood or rocks in there that reduces the amount of water in there a lot.
3" of substrate in a 125 gal tank displaces 16.83 gal alone of water so you have only 108.17 gal of water.
The tetras and cories need about 1 gal of water per 1" of fish. I'm not sure what type of cories and tetras you have but lets say they average 2" each, they would account for 110 gal of water and you still have not factored in how much water is displaced because of the plants and other decorations.
You have no room for discus in that tank.

[Orange Crush]

To know the exact volume of water in a tank also helps when you are medicating. That you don't overdose.
It depends on how high up you fill the tank, perhaps you keep the water level lower than what the manufacturer calculates to make it 10 gal.

It is best to medicate only sick fish in a 10 or 20 gal BB hospital tank because when you put decorations, substrate etc. in a tank it really changes the amount of water it holds so knowing actual gal a tank could hold means nothing at that point.

[roydooms]

A 125 gal can hold 12 discus (they need at least 10 gal each) but when you put substrate, plants, and other decorations like wood or rocks in there that reduces the amount of water in there a lot.
3" of substrate in a 125 gal tank displaces 16.83 gal alone of water so you have only 108.17 gal of water.
The tetras and cories need about 1 gal of water per 1" of fish. I'm not sure what type of cories and tetras you have but lets say they average 2" each, they would account for 110 gal of water and you still have not factored in how much water is displaced because of the plants and other decorations.
You have no room for discus in that tank.


I would like to hear other members' opinion on this one. If that is the case, I can easily move the smaller fish in a smaller tank. After all, it's a discus tank.

[roydooms]

It depends on how high up you fill the tank, perhaps you keep the water level lower than what the manufacturer calculates to make it 10 gal.

It is best to medicate only sick fish in a 10 or 20 gal BB hospital tank because when you put decorations, substrate etc. in a tank it really changes the amount of water it holds so knowing actual gal a tank could hold means nothing at that point.

I only have a small sponge filter in it and I always will up my tank as high as I could. Barely touching the top brace. I drained 5g and almost or was it 1/4 that was left.

[kent1963]

Listen guys this "10 gallon" rule is simply a guide-line there are no hard and fast "rules". Keeping fish of any kind is all about variables, tank size is not the only deciding factor. That said 40 breeders are one of my favorite tanks for grow-outs. I routinely overstock my tanks but you have to be very diligent with your care, there is very little margin for error. Larger tanks are easier to be successful with.

[roydooms]

Listen guys this "10 gallon" rule is simply a guide-line there are no hard and fast "rules". Keeping fish of any kind is all about variables, tank size is not the only deciding factor. That said 40 breeders are one of my favorite tanks for grow-outs. I routinely overstock my tanks but you have to be very diligent with your care, there is very little margin for error. Larger tanks are easier to be successful with.

I agree completely with you on this one. Saying that a slightly overstocked, properly cared 125 doesn't have a place for discus IMHO is crazy. Even the inch of fish per gallon is just a guideline and you can go over that with proper care.

[Orange Crush]

I agree that once you know what you are doing then it is okay to break the rules but when someone is asking about the basics then it is best to tell them the rules for success. What they do with that is their choice. I would never recommend to someone to keep juvies in a heavily planted tank with substrate just because a few of the more experienced keepers have been able to do it.

[roydooms]

I've been taking care of discus for over a year. Still a rookie. But I'm not new to aquariums. I've had aquariums since I was a kid(15yrs total). I know how things work. Assuming that a certain tank holds the "exact" volume of water It claims is a basic mistake. I assure you that none of the tank holds the exact water that they claim. My discus in the 125 are close to a year old and some are over a year. I don't think I would claim that as juvenile or maybe they are still but you don't know my maintenance and how I care for them. All I ask is for the exact volume. I don't think that's a basic question if you can't even answer it.

[Orange Crush]

Asking how many discus can go in a 40 gal or a 125 gal tank is about as basic as it gets and since you have been a member here for a year I am surprised you were even asking it but I am only trying to help you. And if you have been keeping fish for so long then you should also realize that having substrate, plants etc. means it is not nearly 125 gal of water in that tank anyways and that the dimentions at this point have very little to do with that.
Since you do not agree with what I have said I am going to stop answering your questions on this thread because I am wasting my time. I Hope that you can find someone that will tell you what you want to hear.

[roydooms]

I've been a member for over a year but I just recently became active a month ago. I've been reading and staying quiet and jut learning from the posts. I know the 10g rule but I like to see members' opinion on things and not just the basic rules. The reason for the questions. Obviously, I know that my 125g holds less that that because of what I have in it. And as for your opinions, you are right and it's up to me if I'll follow them but don't push them. That's why I also ask for other's opinion. Also, don't answer something that you don't know the right answer or assuming it's the right answer(exact volume). Don't mean to waste your time but if I think something is not right an I know I am right, I fight for that. So I think this argument is not going to end. So might as well drop it now. Thanks for all the replies :D

[TNT77]

Easiest way to find the exact amount of gallons is to take the tank dimensions and subtract glass thickness..if you want an exact fill amount measure to the fill point of your tank.

[roydooms]

Easiest way to find the exact amount of gallons is to take the tank dimensions and subtract glass thickness..if you want an exact fill amount measure to the fill point of your tank.

I will do that. Thank you :)

[Juliah09]

I have a 45G tall tank, was wondering the same thing how many juvie discus I could put in, now after reading this no more than 4 but I'd like to go with 6...

[Eddie]

I have a 45G tall tank, was wondering the same thing how many juvie discus I could put in, now after reading this no more than 4 but I'd like to go with 6...

Well you are talking about long term. Juveniles are small so you can grow them out in a 45 with adequate water changes and good feeding but as they mature/growout, it will get tight.

[Wjmulder]

This 10 gallon per discus "rule" has me wondering. If this is based on adult discus then what size adults? If your adults are 6 inches then you should be able to have more than if they are 8 inches right? How can anyone be so adamant about pushing this rule when there can be so many variables. Adult discus can get to 9+ inches, surely the rule must apply to that size so smaller adults must mean you can have more?

[Larry Bugg]

This 10 gallon per discus "rule" has me wondering. If this is based on adult discus then what size adults? If your adults are 6 inches then you should be able to have more than if they are 8 inches right? How can anyone be so adamant about pushing this rule when there can be so many variables. Adult discus can get to 9+ inches, surely the rule must apply to that size so smaller adults must mean you can have more?

I would like to see these 9+ discus!! A 8" is considered a Jumbo. 6" to 7" is pretty much considered the average. The 10 gallon per adult discus is just a guideline. Lots of people keep more than that but when someone ask how many they can keep in a tank one pretty much assumes they are fairly new to discus keeping. When giving advise to new people it is generally best to give them the general guideline. Guidelines are usually given using the average not the max in mind. I've never see a 9" discus.

[Wjmulder]

I agree with you on all points Larry, I think the key word is "guideline". Some on this forum are so determined to push guidelines as set in stone rules not to be questioned. A little flexibility now and then is refreshing.

When I started looking into getting discus I read somewhere that they can get to 9 or 10 inches. I assumed when I started reading this forum that anything less than 8 was stunted, then I recently saw threads calling 7" jumbos. Now I won't feel so bad if my discus only reach 6"

[Juliah09]

Thanks so much for the advice! I will probably grow out 6 to begin with and see how well I do with this new addiction...and care... This is all so new to me but need more in the tank I have due to bullying right now.


Well you are talking about long term. Juveniles are small so you can grow them out in a 45 with adequate water changes and good feeding but as they mature/growout, it will get tight.

[Larry Bugg]

I agree with you on all points Larry, I think the key word is "guideline". Some on this forum are so determined to push guidelines as set in stone rules not to be questioned. A little flexibility now and then is refreshing.

When I started looking into getting discus I read somewhere that they can get to 9 or 10 inches. I assumed when I started reading this forum that anything less than 8 was stunted, then I recently saw threads calling 7" jumbos. Now I won't feel so bad if my discus only reach 6"

Lots of people look at a Jumbo and say.......wow that discus is 9" but then if it is pulled out and measured it is only 7" to 8".

I think a BIG part of the problem with this thread and a lot of others recently boils down to a couple of things.

First when someone ask for help with basic discus rearing it is a natural and probably correct assumption that the person is new. The absolute best answer to give a new person asking for help is what is "tried and true". That is the advice that you will see here most of the time and I believe it is the right advice to give. I have seen a lot of threads lately that talk about how inflexable the regulars on Simply are. I think that is a bunch of boloney. They are giving the tried and true methods. Most of the "new" ideas that posters come up with aren't really new at all. Posters come up with a new idea and the long time posters here will either say it won't work based on experience or they will say try it and let us know how it works out. It is very rare that someone actually tries it and then post the results.....positive or negative. The second problem is that lately it seems there are some who are fairly new to discus keeping that love to dole out advice and it is based on what they have read, not on their actual experience. I have kept aquariums for over 50 years but I have only kept discus for about 4 of those years. After 4 years I don't consider myself as anything close to a discus expert but we have those that have kept discus for 1 or 2 years and they do consider themselves capable of doling out the advice.

There, that is my rant. It has been building up for a few weeks or months lol. For what it is worth my advice is to spend enough time hanging out here that you can eventually figure out who you should or shouldn't listen to oh and don't knock the old timers..........they do know what they are talking about based on experience.

[discuspaul]

Lots of people look at a Jumbo and say.......wow that discus is 9" but then if it is pulled out and measured it is only 7" to 8".

I think a BIG part of the problem with this thread and a lot of others recently boils down to a couple of things.

First when someone ask for help with basic discus rearing it is a natural and probably correct assumption that the person is new. The absolute best answer to give a new person asking for help is what is "tried and true". That is the advice that you will see here most of the time and I believe it is the right advice to give. I have seen a lot of threads lately that talk about how inflexable the regulars on Simply are. I think that is a bunch of boloney. They are giving the tried and true methods. Most of the "new" ideas that posters come up with aren't really new at all. Posters come up with a new idea and the long time posters here will either say it won't work based on experience or they will say try it and let us know how it works out. It is very rare that someone actually tries it and then post the results.....positive or negative. The second problem is that lately it seems there are some who are fairly new to discus keeping that love to dole out advice and it is based on what they have read, not on their actual experience. I have kept aquariums for over 50 years but I have only kept discus for about 4 of those years. After 4 years I don't consider myself as anything close to a discus expert but we have those that have kept discus for 1 or 2 years and they do consider themselves capable of doling out the advice.

There, that is my rant. It has been building up for a few weeks or months lol. For what it is worth my advice is to spend enough time hanging out here that you can eventually figure out who you should or shouldn't listen to oh and don't knock the old timers..........they do know what they are talking about based on experience.

I agree with everything Larry has said here.

[Wjmulder]

Larry's response, Especially the second problem part, is exactly what I was looking for :)

[Larry Bugg]

Thanks guys. I started to post something similar on a bunch of threads recently and then thought better of it. I finally had to let it out, lol.

[ajoshi9194]

For time being you can keep a few juvies.
As u mentioned u have 5 discus of 3.5 to 4.5, seems fine to me, atleast for now.
When they will grow to full size, it might be congested.