Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
What are water parameter's Ammonia,nitrites,nitrates?
How long has tank been running with fish ?
Twenty gallon in my view is too small for Adult Angelfish, but could house juvenile for a few month's.
Healthy cichlid's, (Angelfish are cichlid's) should grow at a rate of one inch per month or thereabout's.
Do not accept myth that fishes only grow as large as the tank.
Nearly all fishes,,, kept in too small of enviornment's, will become stressed, stunted,sickly, over time.Some faster than other's.