Pool Products Pool Shock 24×1 lb.

Tri chlor shock is the only thing that works to kill the black algae that I occasionaly get in my pool.Tri chlor shock is very hard to find this year (2023) because the two main chemical plants that manufacture it are shut down for repairs.The price at my local pool store chain has doubled since last year and is now $11.99 for a 1 pound bag, and I use 3 bags at a time to kill the black algae.This Aqua Clear Tri Chlor is the exact same concentration as the pool store brand, but the price works out to only $3.53 per 1 pound bag. A true bargain.The only drawback is that it comes in a box of 24 one pound bags, which will probably last me 4-5 years.