The sieve type filters are just for mechanical removal of waste. A filter needs two sections, one to remove as much visible waste as possible and then a biological section that processes dissovled waste such ammonia & nitrite.
Do some reading on the "Nitrogen cycle" which should give you the background info you need and then you can look into such filter variations as multibay filters, bead filters, Nexus, shower systems etc.
Posted on Jul 13, 2005, 3:38 PM from IP address 135.196.99.93