Hi guys new here and I have learned A LOT!!! Currently have to vaccum my 18K gallon pool daily. Get a build up of a brownish yellow "dust" on pool bottom. THought it was algae, but it stay to the bottom and does not move up walls, thought maybe pollen, but thaqt would be a lot of pollen everyday. My question is I use the bleach and acid from the BBB system, and have concretet garden brincks holding my wedding cake steps down. Could the by deteriorating and adding to this problem? Other ideas or help? Need to cleaqn my filter after everyvaccum session or it just spits it back out.