Ive had one for 30 plus. Upgraded to the 4 ft to 6ft in 2017. I get tissue paper algae around the late July mark... never f...... fails. I let my adult kids deal with it now, as the grandkids are the ones to swim. Ill pay to maintain till they are done with it, but my youngest granddaughter is 2, so it will be a while yet. Mustard algae is a bitch, I had it once, and have used a silver recovery system since. It sterilizes the water. Look into a 'nature recovery system' on Amazon. It's a lifesaver.