I love these filters too! I fill mine with floss and change it out every 3 weeks or so. I notice no decrease in flow and could probably go longer. I run 2 on my 55. The other is polishing. I change out the micron every week. I have 2 carts...one in the filter and one in the bleach solution. To be honest though...the flow is strong...not all fish are gonna appreciate it. My plants move around alot!!!
