I've been using Phosguard for about a month now. Before I started using IT my levels were at 1 ppm but have settled at .1 ppm. I've been placing Phosguard in my canister filter but last week I finally got a reactor and put it in there. However, my levels seem to be holding at .1. So far I've only been using 1 cup each time for my 65g setup. Can I adjust the amount I use up? I still have algae issues and I think it's taking up some of the phosphate as it grows keeping my measurable levels artificially low. I just don't want to use too much and screw something up. The directions say to replace it every 4 days if the levels aren't going down so it's due to be replaced and I thought I'd up the amount to 1-1/2 cups and see if that doesn't help.