My pool is 26k gallons and 8.5ft deep at the deep end. For almost 20 years I've spent hours upon hours, treatments upon treatments, brushing and brushing the sides to fight yellow algae.

There was a post earlier today of a canister filter that looked exactly like mine have looked over the years, slimy yellowish yuck. I am now two years in of not seeing so much as a hint of yellow algae almost the entire year. I started with Pool/RX (~$95, which I have come to find out is mostly just copper sulfate. I learned this from a friend who is a water treatment expert.).

Instead of replacing the Pool/RX basket twice a year as recommended, I add two capfuls of copper sulfate dissolved in a bucket if the dreaded yellow menace tries to re-establish itself. This it typically maybe once or twice a year at most. My water expert guy did the math on how much to use for my pool size. (There's a lot of information online about parts per million dosage.)

I clean the filter canisters at the beginning and ending of the season and it is so much easier. They are basically just an off gray color now, then white after cleaning.

Net-net, the pool is sparking clean and clear year round. I purchased what looks to be a lifetime supply at Amazon for $27, 3lb jar. Side benefit is the water skeeters and occasional water bugs don't like it so that's nice too.

You'll want to read up on it. (Google copper sulfate in pools.) I use an incredibly small amount well within safety standards. More is not better, more is worse and can be dangerous. Like anything pool chemical-wise, know what you are doing and you'll be fine. For us, we have zero algae, zero stains, no equipment failure, etc. and no one has green hair. :-)

Just wanted to post this in that in might help some of you struggling with algae and slimly filters.