My neon blue (aka cobalt blue) discus is very bold and friendly with me, but my attempts to introduce him to other discus have been unsuccessful. He is really quite a bully. I have to keep him by himself with just catfish in a 46 gallon tank. I’m just wondering if certain strains of discus are more aggressive than others, and if this one will ever be able to live in my bigger tank with the other discus.

Yes, some species are. Actually I have found a quite nice species profile on Discus…

http://aquaticpassion.animal-world.com/index.php?showtopic=1004

I have two discus in a 30 gallon tank, and one is always chasing the other into a corner or just all around the tank, and it looks more aggressive than playful. The dominant discus nips at the other one, but there is no fin damage (yet). If this is a big problem, please let me know what I can do to fix it. Thanks!

Yes, this is a problem. They need to be separated. The one being chased will eventually die from stress and/or exhaustion. (likely sooner than later.)
I don’t know much about discus (except that they are not a good beginner fish), having more than two may help matters by spreading the aggression around, HOWEVER, your tank is not big enough. Your tank might not be big enough for the two you have now.

Well after dealing with the problem of my Male Discus. My other pair has spawned and for the fifth time on the second day of taking care of their eggs they have ate all them. And every time its on the second day they don’t go white or anything but they still eat it. I have tested all the appropiate tests for it too see if there is any ammonia or nitrates or anything that would make it eat their young but they all came back normal. They are kept in a simple tank with gentle filtration with nothing disturbing them like loud noises or other fish in the tank. They also take really good care of their eggs as they take it in turn to feed and fan the eggs so i don’t know whats wrong. Also i think that the eggs are fertilised as they don’t turn white but what do discus eggs look like fertlised? Please help!

Discus eggs, and other cichlid eggs, are typically a clear and/or slightly pink color when fertilized.

If they are young discus, I would give them another chance before taking the eggs and hatching them yourself. Raising discus fry is very difficult because part of their feeding when they are very young is actually off the mucous excreted on the sides of the parents.

If your tank is in a well traveled part of the house, they could be bothered by pets or people walking past the tank. Try taping some black poster paper on the front and one side (the side closest to the eggs) of the tank next time they lay eggs to cut down on outside motion.

I would also put a small night light (like for a kid’s bedroom) next to the tank so they can see the eggs at night after the tank lights are turned off.

I have a 55 gallon fish tank and want to know how many discus i can put in it and what fish get along with it.
I also want to know how to set up the tank.

First Of All Lilro Is talking RUBBISH!
Discus require 10 gallons per adult and please please please! do not buy Discus if you have only kept fish for a year or 2!

If you want your Discus to grow to the maximum size, Please do not plant your tank. Have a BB(Bare Bottom) tank