for a 55 gallon tank i would go with a trio of apistos (1m, 2F) a shoal of 50 cardinal tetras and a school of 20 sterbai or schwarzi corydoras
Overstocked much?
Might be okay with daily water changes.
over stocked? are you using a rule here? sometimes some self working out is better than following the 1 or 2 inch per gallon rule IMO its a useless rule
corydoras produce very little waste, cardinals dont produce much waste for their size either. IMO its better to work out stocking from the waste produced instead of size because its more accurate. i would have no worries about putting 50 cardinal tetras in a 30 gallon because they produce little waste.
Even if you followed the 1 inch per gallon rule, your stocking list is WAY over!!
im not on about using rules. i cant stand them theyre all wrong anyway. and dont compensate for the size of the fish, the waste produced etc.
a reason why it doesnt work.
an 8 inch severum is going to produce more waste than 8 cardinal tetras. yet both take up 8 inches of stocking space. IMO what i suggested would be fine in a 55 uk gallon tank. fish keeping isnt logical anymore its all rules! and thats wrong. your tank is over stocked IMO if:
nitrates rise to 40+ppm in a week
you have ammonia or nitrite readings (ammonia is always present in a tank but our crappy hobby test kits cant pick those small levels up)
your fish cannot move.