Stocking advice needed too

[RinaLane]

I have 2 tanks, 40G & 75G. Small one just has 18" long pleco, big one has 6 discus fish in it.
I bought 12 Hemigrammus erythrozonus & 10 Mikrogeophagus ramirezi. In which tank should I put them? I was planing to add tetras to pleco & rams to discus. But now I second guessing what if pleco will kill Hemigrammus erythrozonus....
Thx!!

 

[fluttermoth]

Even big plecs are fairly peaceful, I wouldn't worry too much about it killing the tetras.

I have to say, the plec really needs a bigger tank, and that's probably too many rams for the other tank; they're quite territorial, especially if they start pairing off and want to breed. What are the dimensions of the tanks?

 

[RinaLane]

18"W x 48"L x 21"H & 36"L x 15"H x 12.5"W