Wooza I absolutely love it. I use it every 10 days with my water changes on my 155g tank. It usually runs for about 7 hours. I've only had 1 algae bloom in 10 years and that was prior to getting my diatom. My water stays crystal clear and free of disease. (granted I haven't added fish to my tank in many years) The diatom states that it filters to the micron, even filters out some parasites and in very small amounts,
ammonia. (not enough to be a concern for the cycle). It uses Diatomacious Earth (DE) to filter through trapping a lot more fine particles than a normal fitler. You can actually watch the DE turn colors as it filters out all the little cooties that I don't want in my tank lol
What I use is the Diatom XL by Vortex. I believe it filters 400gph. The only draw back is I usually have to replace it every few years. In my opinion...it's well worth the $. As long as I'm an aquarist and these filters are in production, I will have two (one as a spare). Links below.
Ken
http://www.thatpetplace.com/pet/prod/205477/product.web http://www.thatpetplace.com/pet/prod/205458/product.web (DE)
I use this site to order my filter. I buy the DE from Lowe's in the pool supply section. At Lowes you can get a 25lb box of DE for the same price as the 5lb on the site above in the link.
Sorry Jwok..didn't mean to high jack your thread!
Ken