Hi, I'm currently in the process of setting up a 150 gallon ca/sa cichlid tank. I'm thinking of having the overflow run right into filter socks, that being my mechanical filtration and then having a large section for biological filtration filled with fluval biomax ceramic things..... Then a small section for carbon and stuff like that.... Then a last section for my return pump which will probably be a quiet one pro 4000. Being that I'm a kid money is kind of tight.... The reason for me using a 20gallon long is that I have two just laying around the house. I'm just not sure if it'll be big enough. Does anyone see an issue with my setup?