does anybody use a prefilter material before sump?

[mysterybox]

does anybody use a prefilter material before sump?

I just stpped using mine, but it did catch a lot of "crud" from the water, but I was thinking that it might actually cause phosphates to rise as water continually passes through the same crud?

I used a thin "phosphate" by HBH that I put over mt drip tray. Any thoughts?

[Pmolan]

I use it, I guess out of habit. I change it every 2 weeks. Lots o crud.

[mysterybox]

thanks!

[barbra]

I use a filter sock. Change it about every 3 days though. Phosphate isn't the problem, nitrates are.