I do think it is overstocked but only because IMO the platties are the only fish in there that can really thrive in a 20 gal.
Hoplo catfish get up to 4", I would say especially if it's a 20 high and not a 20 long this is too small for them. While I don't have experience with the hoplo specifically, I know that 4" catfish in general need more space than that.
IMO mollies do not belong in a 20 gal tank. They get up to 5" and at that size have massive bio-loads.
I think 29 gals is the minimum for BN pleco, and 40 for butterfly. They also get to 4" and 5" with big bio-loads. The only pleco I would do in a 20 gal is the pitbull pleco. I think a couple hillstream loaches or 4 oto cats make better algae eaters for 20's.
Julii corydoras as well as pandas are great choices for 20 gals IMO/E. Julli's max out at about 1.5" and panda's at 2". Just watch out for the bigger ones like albino's and emeralds that would get too large for your tank. Cories should be stocked in groups of 4 as a minimum, but 6 is what is recommended.
Hoplo catfish get up to 4", I would say especially if it's a 20 high and not a 20 long this is too small for them. While I don't have experience with the hoplo specifically, I know that 4" catfish in general need more space than that.
IMO mollies do not belong in a 20 gal tank. They get up to 5" and at that size have massive bio-loads.
I think 29 gals is the minimum for BN pleco, and 40 for butterfly. They also get to 4" and 5" with big bio-loads. The only pleco I would do in a 20 gal is the pitbull pleco. I think a couple hillstream loaches or 4 oto cats make better algae eaters for 20's.
Julii corydoras as well as pandas are great choices for 20 gals IMO/E. Julli's max out at about 1.5" and panda's at 2". Just watch out for the bigger ones like albino's and emeralds that would get too large for your tank. Cories should be stocked in groups of 4 as a minimum, but 6 is what is recommended.