cal75

We have a fish pond under our gazebo, approx 32000 gals of water. The pond is layered with heavy vinyl, sand on the bottom for the Koi to live in and has been a problem with green water lately. Is there any product to clear up the water while keeping the fish alive. Trust me, no way to catch them all. We have tried Green Clean, thought that might help. Didn't. We set up a large tank with sand in the bottom, to filter the water day and night. Besides a rather large electric bill... water is still green. Thanks for any help.

turbomkt

Add plants? Lots of floating plants...

HeyPK

A really big ultraviolet sterilizer? They make 'em big enough!

Add zebra mussels? (Just kidding! I didn't say that!)

Seriously, What might really work is to pump the water through a mini-marsh. I know that is not what the pond people call it, but the idea is to have a kind of biofilter where you have a lot of rooted emergent marsh plants, such as cattails, irises, and other amphibious plants. The whole mini-marsh is sloped so that it drains into the pond. You have a small pump that circulates the water through the mini-marsh, and the roots of all those emergent plants do something---remove nutrients, filter the water??--- that gets rid of the green water.

plantbrain

Every lake green water issues I've dealt with has done either lots of floating plants, roughly 50% or more coverage or the UV and lots of flow through the UV(about 1-2 cycles of the entire volume per day).

If you can cover the pond, that can help blackout of the system, but it'll come back often.

More weeds helps any algae related issue in lakes.
But then you need to prune and hack the weeds back peroidically also.
There is no free lunch.

Regards,
Tom Barr

www.BarrReport.com

Phil Edwards

Aside from the plants and UV (which I would highly recommend), I would also recommend using barley straw pellets/extract. It naturally and temporarily stains the water blocking a lot of the light while still allowing you to see your fish. I've used it in maintenance applications and it's worked really well. Another product I would recommend is MicrobeLift Summer or PL, it's basically sewage treatment bacteria that will degrade a lot of the wastes in your sand bed that help cause the algae. Those two products and lots of floating plants will do the job nicely and naturally.

Another recommendation for next year, get a bunch of lillies this year. They'll be a renewing source of nutrient uptake and surface coverage from the very start. Use MicrobeLift Spring/Fall to clean out the biomass before the winter starts and in the spring before the sun gets too intense. Also, throw the barley straw in there in early spring as a sunblock as well, that'll prevent a lot of early season algae problems.

Regards,
Phil

PondPimp

Along with the ideas from Tom and Phil (Plants, plants, plants, and UV), Ill add microbelift TAC. I used it on a 48,000 gal koi pond last week, and had clarity to 10 foot three days later.

Also, what kind of filtration and circulation are you using? We usually would run a planted bog/stream, multiple skimmers and biological filters, and most likely bottom drains and pressurized filtration on a koi pond that size.

Jonathan...

Phil Edwards

Hey Jonathan, welcome to APC! I was wondering how long it would take you to make it this way.