BioGuard Back Up 2-1 Quart, Single, Proven Effective Algae Preventative, Non-Staining, Keeps Water Clean and Clear

I love all the BioGuard products, they all work awesome! This algaecide not only kills algae but it will kill all nuisance bugs that get into your pool. Will continue to purchase all BioGuard products & say goodbye to local pool store rubbish products. Thanks BioGuard, you saved me heaps of money.

I use bio guard pool chemicals. They work well.

Works great 👍 and price is right!

Quality product, this brand is great and good price, shipped quickly and on time

This stuff worked AMAZINGLY! I was sick and hadn't been able to clean the pool and when I went to clean it, there were a ton of water-boatman. Followed the directions and came back the next day to zero of the buggers in the pools as they had all died and were sucked into the filter.

My first time using this all season. This year Im not seeing any of the underwater swimmers that terrorized my wife. Plus I’m not getting the dirty bathtub ring around the pool edge either. So something has changed in a good way. I’ll keep it.

This does what it says it will do. I had algae problems in my pool and this really works. I have it on autoship.

Had a bottle of this called just BioGuard Back Up (not '2') from the pool supplier we use. Must've gotten it from them some years back, and it had never been used. Woke one day to a few small algae patches on bottom of above ground (15k gallons) pool, and the pool was crystal clear. Per pool suppliers recommendation used 2 bags shock, 1 gal algaecide and another powdered product to clear it out . Pool became instantly cloudy for 2 days and on third day had a very light green algae cloud, telling me things were not really improving. In frustration, saw this bottle of BioGuard in my pool chemical storage bin and read what it 'could' do. Doubled the dosage to 12 ounces early on that morning, by late afternoon pool had lost green tint. By following day pool was crystal clear and chemically balanced. This has been an unusually hot summer here in the northeast so about every 2 weeks I add 3 ounces and purchased an extra bottle of this so I am not out of it.