I just started a 75 gal and my hope is for discus. I had koi for a long while but had missed the planted tank. I haven't decided definitively yet if I am going to try Co2? The plants are growing albeit pretty slow right now. I have some black neons and 3 white corries and three danios but am going to add a school of cardinal tetra here soon. I won't do the discus until the water is very settled and aged as it is a very new tank and also I am having a knee surgery soon so don't want a complicated fish for a caretaker to tend while I am on the mend.