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

Have used this product for years always worked great at keeping my pool 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.

Per some other reviews I was hoping to get rid of water bugs living off algae that I could not see or find or get rid of with chlorine or any other shock. This stuff did it. No bugs!

Great product.

I purchased this because i had read it kills the swimmer pool bugs. Well, i am sad to report it does NOT kill them. It still works well for an algae destroyer i guess

Works as it should.

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.

Our regular algaecide, we used it for closing the pool.