Quick Question

[ksuyen]

I probably can google this to find the answer, but I love to hear from forum opinion first. My question is (are): can I mix different size Discus in one tank? What will be the impact in terms of fish health and aggressiveness? What will be the best solution for a tank with 1 5-inch discus and 5 3-inch discus? Currently the 5-inch (I call him Groundkeeper) will not allow any other fish to eat any food that has fallen to the ground to the point that one of the 3-inch has refused to eat all and becomes pale.

[warblad79]

Yes, stunting

[ksuyen]

I wonder if there is validity to the thought that the largest will put out a hormone suppresent that slows the growth of others in the tank.

[warblad79]

No offense but it's common sense if the small one will get bullied and don't eat of course their growth will be slow and that leads to stunting.

[Dudley Eirich]

I have successfully grown different sizes of discus in the same tank. If they are all juveniles, there is less of a problem. Once they reach breeding age, aggressiveness increases, so it might be time to give them their own breeding tank, which will solve the problem That said, you may occasionally find one juvenile fish that has a chip on it's shoulder and feels the need to bully more than normal (sounds almost human-like, doesn't it?). You can help the most bullied fish (usually the smallest, although not always the case) by having more discus in the tank to spread out the aggressiveness. In the case of your groundskeeper fish, if you feed at both ends of the tank, the bully cannot be in two places at once, so the others have a chance to grab some nourishment. You can also put the bully in a separate tank (in the cooler, if you are a fan of Hogan's Heroes) for a while and reintroduce it back to see if that might help.

[Akili]

Grow out the 3-inch discus by themselves and find new grounds for the Groundkeeper.

[Phillydubs]

I thought you just got a group of like red/whites in or melons that were all the same size?

Was there a bigger one in that group?

[pitdogg2]

I wonder if there is validity to the thought that the largest will put out a hormone suppresent that slows the growth of others in the tank.

yes there is validity to it but that is one of the reasons we do water changes among others. With any cichlid there is going to be some aggression

[rickztahone]

I wonder if there is validity to the thought that the largest will put out a hormone suppresent that slows the growth of others in the tank.

OMG, don't let John see this....

This "theory" is one that is unfounded and many experienced hobbyists will stand by that statement.

[Las Vegas]

When I used to breed Angels, that "theory" I've read is supposed to be true. A lot of my angels would have fry that would seem to grow twice as fast as others. Even with the water changes. But I never questioned it, just accepted it. Kept doing water changes and moved larger ones to another tank.

[Kyla]

if the bullying is preventing smaller discus from eating it sounds extreme enough to merit intervention. if it goes unchecked the smaller fish could perish from the stress or end up stunted.

if u want to keep all the fish, perhaps consider a temporary divider for the tank. i would use a clear divider so the lone large discus can still see the smaller discus (i dont like the idea of keeping a single discus alone).

i had a clear plexiglass divider cut and drilled (to allow water flow) at a local glass shop. it was fairly cheap and worked awesome. i just held it in place with suction cups placed on either side of it so it couldnt wiggle around.

here is a pic of one i used in a small quarantine tank to separate the bullies :)


http://i296.photobucket.com/albums/mm182/kylasfish/Mobile%20Uploads/1A54CFAC-E4C9-4FA8-B347-DCA410BABFC2_zpsfbdm2sxv.jpg (http://s296.photobucket.com/user/kylasfish/media/Mobile%20Uploads/1A54CFAC-E4C9-4FA8-B347-DCA410BABFC2_zpsfbdm2sxv.jpg.html)

[Las Vegas]

That looks good. I did the same thing except I used egg crate.