I've noticed some algae on the bottom of my pool few days ago. It wasn't much and the water was still clear all the way to the bottom. As advised here I started a SLAM process. I actually miscalculated a bit and instead of advised 20ppm SLMA level took it all the way to 30ppm.
After two days of SLAMing the water is absolutely clear there is nothing on any walls or bottom, but my overnight test still fails. Last night between 8pm and 7am it dropped by 5.5 ppm.
Any advice on what else I could do or what could be causing this?