Hi. I have a 35,000 in ground pool with a vinyl liner for 5 years. I seem to have fits with a scum line but also this tar like goo that builds up in the slimmer. I keep everything pretty balanced, shock weekly, mineral cartridge. I even use the little sponge things which turn black almost immediately. I am not sure what else I can do. Thanks.
We would recommend a maintenance product call Pool Perfect by Natural Chemistry. It’s a natural enzyme that biodegrades the organic matter that can cause scum lines.