I used my algae scrubber for the first time today, because there was a little brown spot on the glass I wanted to remove. I neglected to read the directions, so I didn't see I was supposed to rinse it first. After I scrubbed off the spot, I noticed little teeny pieces of blue on the sand. I tried to siphon out what I could, but it was very hard to get all of it. The particles of blue stuff are as fine as the sand itself. I'm worried about it hurting my fish. The scrubber is polyester fiber. Maybe I bought a cheapo brand. Anyone know of any good quality algae scrubber brands? Thanks!