2 Aqua Clear 110's is plenty. I used 2 on a 150 which was heavily stocked. I never saw ammonia or nitrite in my tank once. People add like ten or buy $400 canisters for no other reason then machoness and trying to be Tim the Tool Man Tailor. I have a 150 gallon running for like 3 years now on only two AC 110's. The stock is a breeding pair of jags and like a million babies. I feed the babies like nuts then remove them for selling, to repeat the cycle. So if my water quality is good enough to raise fry, my friend you will be fine with only 2 110's