BioSafe Systems 3002-8 Algaecide Granular Algeacide, 8-Pound, White

This product works. Here are some suggestions if you have koi: Day 1. Use half the recommended dose the first day. Day 2: use beneficial bacteria. Day 3. Use the second half of the recommended dose. My koi didn’t even seem to notice the algaecide. They never seemed to struggle. The directions were unclear about the recommended dose. With a little Google digging, I found that you should use 1 cup per 1000 gallons of one water. Hope this helps!

Best product

Works great

It doesn’t really work in my koi pond. The algae just clump up

It works well in killing the algae, although it doesn't really clean it up. It does have chemicals so I would stick to the recommended dosage. I have a 500 gallon running pond with 6 koi fish. I stop the running water falls and sprinkle about 1/2 cup of the algaecide with my hands (use rubber gloves). Within 15-20 minutes, you can see the green algae die and float to the surface. Some of the algae just turns brown and sticks to the surface. Then I restart the water circulation and I have a clean pond. It takes about 3-4 hours for the sediments to clean up. I typically apply this once a month and wait a day for the filtration system to clean up the dead sediments. I change / replace the filters a day after the application.This is a one-time clean up chemical.You still need natural algaecides to keep the water clean between applications. I use microbe-lift, barley straw, and aquatic plants (covering about 1/2 of the pond). This seems to do the trick. My string algae growth has reduced substantially (although not completely eliminated) with these measures.