certainly an easy install, just drop it in the skimmer. it seems like we use less chlorine and the water stays clean and clear. can't make a scientific comparison to not using it, but I'm convinced enough I'll buy one again next season.

Mine had the top busted off and about 1/4 of the crystals spilled through the box. I was able to reassemble but that and certain other aspects of the packaging make me suspect what I received had been a previous returned item. I don't know why but the last two now (one per season) have come in damaged. The Mfg should take more care to shrinkwrap or somehow seal the product for transport. Since my repair it does work well, heck this is the exact thing the pool supply stores DONT want you to know about since it truly is hard to believe how well it works defeating algae. My pool workload is less than ever, and I hope Instant Frog does not get 'accidentally' axed by the pool chemical mafia.