You should give seachem's purigen a try. It lasts for a few weeks/months, can be recharged, and can be had cheaper than most other water clearing solutions. It is a small bag you put into your filter. It has worked well for me.
agreed...it really is awesome and cleared up my tank, every time I set one up...Purigen is great stuff. You don't need the charcoal--just fill the container with fitler floss--I've been doing it that way for yrs. Exactly how to incorporate the purigen into that filter is a bit tricky--the little bags are easier and can be slid between the screen and the floss....or the pre-filter sleeve and the screen. :thumbsup: