30 gallon
A very small filter. Only cleans good for about 2 months if fed in seprate tank. The filter looks like it should be in a five gallon tank though. It cleans okay for a filter that small.
Overall 3/5
20 gallon
A HUGE filter. It looks like it should be in a 90 gallon tank. Not a 20. It cleans most of the crap on the bottom. 1 month runnin strong. Not noisy at all.
Overall. 4/5
If you have a 30 gallon and want a new filter but these two together. You will love them!

