There’s a stainless steel brush shortage round here apparently. Algae, algae everywhere. I’m using the old one currently. Plastic snaps off almost every brush. I’m ramping up search.& you don’t need to buy a whole bunch - just 1 or 2 for now. They usually sell them in individual wrappers in the US. Not sure where u are.
Or just go with the liquid chlorine in a little pump garden sprayer - just be sure to rinse it out when you’re done each time so it doesn’t get gunked up/messed up.
Pretty easy- just pour it in the pool & rinse her out real good.
For now just keeping with slam level fc & aggressive brushing will certainly help.