45 gal with Discus?

Even under ideal conditions, most hobbyists discus will not get over 5-6 inches. As long as you keep the tankmate stock to a minimum, and keep up with routine water changes for the discus, you could keep 4 discus in there. 3 is not a good number for discus, one will surely get picked on until it gives up and dies. As for tankmates, albino cories and sterbai cories tolerate the higher discus temps very well. And although ideally everyone says keep a minimum of 6 cories cause they'll be happier, I have 3 albinos in my discus tank, 3 albinos in my bristlenose breeding tank, and 2 julies in my QT tank, and the are perfectly happy and fat as heck. I wouldn't put german blue rams in a 45 with the discus, they are just too territorial when they breed and even with the size difference between them and discus, they will aggressively "ram" the discus at breeding time and keep them all away from "their" side of the tank! Just not worth the stress on the discus unless you've got a real large tank to give everybody their own space. Some cardinals, neons (I keep neons), and a bristlenose pleco would be fine. Green tetras (blue in color) are also fine, but hard to find. Rummynose are also good, but I prefer not to have such an active fish in with the very slow swiming discus. I've done black neons too and they are fine. Hope this helps.

Debbi

a 45 is enough IMO

Actually ,under "ideal" conditions, they will approach "dinner plate" sizes. A 45 is not the best choice for a discus tank. A 45 would make a nice sump for a real discus tank (eg: you can still use the 45 later on when your discus get to ~7" and it's time to upgrade to a 90+).

You could put 4 Discus in there and you should get good sized adults if you do your water changes.

I would not bother with tankmates. Go for a species only Discus tank, heavily planted with a sand substrate. Employ the services of about 20 Malaysian Trumpet Snails to keep the sand clean, and watch them thrive.

a 45 is feasible but a 55 would be better.

4 is considered the minimum number to keep discus in..however, they discus will tend to exhibit better schooling characteristics and feel more comfortable at 6+ in the tank.

at this number you would need alarger tank. but can use a smaller tank for growout.

that said I have seen adult discus much larger than 5-6" and dinner plate size is actually very real.

4 max (no more, no less either).

-Ryan

a bit small for discus mate....better with a 75g for discus as they are pretty territorial in small numbers in a small tank