I have a brick in my sump for over a month, still have high No3's, >20 ppm
I heard recently that these bricks leech out after a while, is this true.
BRS did a research test for Chaeto, with different lights, to see if the algae made a difference, the results were amazing. The most expensive lights grew the algae quicker, but regular bulbs, energy savers, also did the same job with No3's, but the Chaeto was denser, greener, but grew at a slower rate. I can't get Chaeto to grow, I run the light 24/7