GreenClean Blue Colorant Concentrate - 16 oz - For Koi Ponds and Water Features. Safe for Fish, Plants, Pets and Wildlife.

I bought this to use in my outdoor pond and I was not impress with the end result. Its only takes a little bit to turn the color of the water blueish. the problem with using this in outdoor ponds is the blue does not really look blue against a green background of a pond. the water becomes opaque. I use just a small amount in my pond and it went from crystal clear to pitch black. i left it in my pond for 2 weeks thinking it would clear up over time but it didn't. I had to drain and refill my pond. as for slowing down algae growth I did not see any difference. I think this would work best in a pool or something with a light background.

I purchased this product along with GreenClean Granular Algaecide granules and tablets. I also ordered CrystalClear PondShockSold by: Airmax, Inc. I followed the instructions to the tee about a week ago and I have not seen the bottom of my pond or my 28 fish since. Two of my Koi's are about 15 inches long, primarily white in color with orange and black, along with several others between 9 and 12 inches long. You would think they would be hard to miss. My pond is so green even with a bright light I cant see anything. I've drained it down to about a third of the way 3 times and still green.My pond is 14 x 6 and 14 inches deep at the shallow end, about 2 feet in, and the rest is about 20 inches deep. this is roughly 1100 gallons of water. I have a very nice waterfall, live lilies, 2 aerators and 4 pumps. Two pumps have one filter, one pump has 5 filters and one pump is a 1500 GPH pool pump I purchased just for this pond. I change the filters at the very least 3 times a day and they are Green and full of a lot of muck or algae or whatever it is in there, every time. I also have 5 sucker fish and one of them is 9 inches long! I just pray my fish aren't in there dead!!

Excellent product. I have used this colorant during the summer heat of Las Vegas for 10 years and it almost completely reduced the excessive algae growth I had experienced in the past. It will not completely eliminate algae growth but will allow you to reasonably control and manage it.

Just as advertised. It helps block algae growth in our ponds