









🔵 Clear waters, confident ponds — algae doesn’t stand a chance!
Crystal Blue Copper Sulfate is a premium 99% pure granular algaecide designed for large ponds and aquatic environments. It effectively controls filamentous and string algae in water temperatures above 60°F, with flexible application methods including dissolving, broadcasting, or dragging. Use responsibly by treating half the pond at a time to preserve oxygen levels and protect sensitive fish species. Ideal for professionals and pond enthusiasts seeking crystal-clear water and sustainable algae management.






| ASIN | B000RUN0T6 |
| Allergen Information | Abalone |
| Batteries Included | No |
| Color | Blue |
| Customer Reviews | 4.4 4.4 out of 5 stars (2,270) |
| Date First Available | 7 August 2012 |
| Item Form | Granules |
| Item Weight | 2.24 Kilograms |
| Item model number | 333 |
| Number of Items | 1 |
| Pet Life Stage | Adult |
| Product Dimensions | 10.16 x 10.16 x 25.4 cm; 2.24 kg |
| Quantity | 1 |
| Size | 5 lb. |
| Specific Uses | Outdoor |
| batteries required | No |
M**H
I have a 400 gallon pond with a waterfall and I always had an algae issue until I bought this. I know I poured a little too much in but I was thinking "what the heck". The pond was cloudy for a few days and then it cleared the water up and now it looks fantastic! Crystal clear. What a great product ! I would highly recommend this to anyone who has a pond with an algae problem !!!
F**Y
Does the job. Distribute through your toilets. Keeps those lines clear of roots as well as the septic itself.
C**E
Works very quickly, easy to use. Wear a mask when spreading this! It got rid of a snail and parasite problem within hours!
A**R
As advertised
M**B
I've tried several different chemical options to treat my ornamental fountain in my backyard, and nothing worked until I used this stuff. Because my fountain is in the full sun, most traditional chemical treatments are ineffective and the algae blooms even when I dose at 2-3x the recommended treatment levels for my application. I had previously tried Tetra Pond Fountain Blocks, EasyCare Fountec Algaecide and Clarifier (worked somewhat in the spring but not the summer) and three of the AquaScape autodosing system treatments (Prevent, Control, Maintain). Not one of them worked, and I would typically have to drain and powerwash my fountain after 3-4 weeks to get a clean, clear fountain again. This stuff is AMAZING! There aren't doing instructions on the label for small areas like my fountain (this amount of chemical is enough to kill all the algae in a 10 acre pond), but you can find it on the internet. For my 500 gallon fountain, I put in 1.5 tsp every other week. I have had ZERO algae growth! This container will last me for many years, so it's not only incredibly effective, it's also really cheap. Everything I've read online would indicate it is safe for animals drinking the water, but it's not safe for fish.
Trustpilot
2 weeks ago
2 days ago