CrystalClear Algae D-Solv Pond Algae Control, Fast-Acting EPA Registered Algaecide, Use in Fountains & Outdoor Ponds Containing Koi & Other Fish, Treats 5,760 Gallons, 16 Ounces

This was recommended to me to The Pond Guy. We had some extensive work done on our pond this past spring, and the people who did the work also said they’d clean our pond… they used a pressure washer. A real no-no, as the spray is too harsh and washes off all the ‘good algae’. A plain garden hose would have sufficed and been far better. Anyway, flash forward 8 weeks and I had the worst string algae ever. So thick… I used a stick to pull up globs every morning, and that didn’t touch the issue. It just got out of hand. Our pond is small – only 500 gallons. I used 1-1/2 ounces - first I cleaned a bucket very well, then dipped it into my pond and collected a bit of pond water. Then I added the Algae D-Solv to the pond water, swished to mix, and gently poured it into our pond. I repeated this every 3 day, for a total of 3 times. After the 3rd day of the 3rd treatment (12 days later), there was NO string algae. None. Of course, throughout the treatment I did have to clean the pond, the filter, and skimmer daily. Also, I have 2 falls, and added 4 bubblers while I treated the pond, for added aeration, which helps. Unfortunately, it left my pond very turbid. I couldn’t see the fish, or anything. Tried water changes – several. Added beneficial bacteria (unnecessary). No help. Finally ordered CrystalClear RapiClear Liquid Flocculent – one treatment did the job. After that, I occasionally treat the string algae, once, which does the trick, and several days later add the flocculent. I have comets and shubunkins, and because I know my pond’s correct volume, they were never harmed, nor were my water lilies, hyacinths, or other pond and bog plants. I also had a couple comet fry, and they are fine. Not a fan of adding anything to my pond. I'm a big believer in letting nature do it's thing. But sometimes the pond needs a bit of human intervention to keep it healthy. UPDATE: The weather has cooled off here, and this product does not work as well in cool/cold weather, BUT it does work - you need to give it time. My string algae started to return so I did 3 treatments, adding the D Solv every 3 days. After the 3rd treatment I just gave the pond a few extra days and sure enough, it's totally clear of string algae once again (average nighttime temps are in the low 50's and I've stopped feeding the fish, of course).

This is really a great product. When used as directed, it does kill string algae. Be sure to follow the directions.

This Algaecide works well for my water feature fountain after initial 2 weeks of use, fast acting, will see how it works as the weather heats up in Phoenix.

I have struggled with green water for 7 years. Without a lengthy history, I bought this product in May of this year. I followed the directions perfectly and it cleared the water without any real issues to the fish the first month. The aeration is superb. There, I am above reproach. Also, I have never lost a koi. These fish know me and I care for them. I will admit when I poured CrystalClear into the water, the fish would go into a very still state for about a day, and they would not eat but sluggishly come back to movement by 48 hours. That was OK with me because the water started to clear. Well, in June I followed the same direction and the fish started to swim erratically within an hour. I could see the distress. I instantly started moving the water out but lost 9 koi out of 27. A third! They just went belly up within hours, even with a frantic water change from a 210 foot deep well (no chemicals) and similar temp. We are heart-broken, of course. Pretty mad too as i go through the stages of grief. Stupidly, I thought "Can't be the product", so I tried once more at half-strength and BOOM, the fish went sick. Drained again. That stuff has no place in water with fish. I am very sad and poorer. Find another product, people. I can see that there are other koi people that had a similar experience, and it's not good to have something that can turn on you and your loved ones so fast. It is a deadly product.

It works very well; the water cleared up to where we can see all our fish.

I have a 1600 gallon koi pond that turned green from algae the first time in a decade. I have fought string algae before but not the pea soup kind. We immediately reinstalled the ultraviolet light filter that had been removed for lack of need. The filter began to help but it's a slow process. Ordered this product but was worried about the warning for humans and pets. So I called the company and was told it is only harmful to pets if consumed right out of the bottle. Still cautious after reading horror stories with algaecides, I applied 1 ounce only of the 4 oz recommended dose. Nothing tragic happened and the water started to clear. So the following day I added ounce #2 of the recommended dose. The water cleared enough to see the pond bottom. It is 90% clear at this point so I am going to let the filter handle the rest. We did have adequate aeration and watched the filter carefully for buildup. All in all, I am very happy with this product and the fact that I had to use so little. If you are concerned at all, try stair stepping the doses to minimize the oxygen drain and see how it goes.

I have Administered 3 doses to my small pond and have not seen much of an improvement. The directions on the bottle are also rather useless as they don't even explain how to Administer the product. I used directions from a product i used previously.

Cleared my water right up