Can't get rid of Pea soup pond algae, AND I just killed all my fish.?

Question

I just put in a new pond this year, about 250 gals. I have been fighting with this free floating algae for months and cannot get rid of it. I have a small waterfall, two small filters, and two bubble makers. It only gets about 3 hours of direct sunlight a day, its otherwise in the shade. I have tried chemical algae killers in which the water turns grey, but in a few days it is a horrible green once again. I have also done partial and complete water changes. ANY IDEAS??

Answer 1

A pond ecosystem needs:
1. Fish (sorry about that!). Fish eat algae.
2. Plants. Plants provide shade and oxygen for fish. Submerged plants (water lilies) and floating plants (water lettuce) are good choices.
3. Aeration (which you have!)
4. Filtration (which you have!)
5. Shade/sun (which you have!)
6. Beneficial bacteria. This is available in liquid, powder, and tablet form at home improvement and pond stores. It should be added when the water in your pond is new (fresh). Read about beneficial bacteria at http://www.pond-doctor.co.uk/longbeneficial.htm. and http://www.pondmarket.com/beneficial_bacteria.htm.

I use a biofilter (basically a big tub with a filtering medium; I use foam blocks) at the top of my waterfall for extra filtration; the beneficial bacteria colonize the biofilter and live there.

One crucial pond tip: Place your pond to avoid rainwater runoff. Chemicals, fertilizers, pesticides, motor oil...anything in adjoining properties can run into your pond and contaminate it.

Answer 2

Sounds like your nitrogen cycle got a little out of whack. And you may have gotten a little exuberant with the chemicals. Now that your fish are dead you should consider letting things reach an equilibrium. You should try barley straw or an ultra-violet lamp for the algae. You should install a biological filter or enlarge the one you have to address the nitrogen cycle. Wait a couple weeks for the water to clear before reintroducing fish. Never do complete or more than twenty per cent water changes, the chlorine will kill your fish quick. Limit the number and size of fish, 250 gal will only support two or three full size koi. and don't over feed. RScott

Answer 3

I use an algae killer by FountainTec that is safe for fish, frogs, birds, wildlife and my two Eskie dogs who think any water feature is there for them to drink. It only takes about a cap full of the solution every week to control the algae growth. I buy it at Target, although I've seen it at fountain, waterfall and pond suppliers and some nurseries.

Answer 4

Try adding a little barley straw to the water. That is supposed to help fight algae. Since the fish are already dead, you could also try adding a pinch of copper sulfate to the water. A little dab will do. You don't need to ad over about a teaspon for 250 gallons. Make sure you wear gloves when using it.