What fish/snails/other things can best clear-up a freshwater pond with lots of algae?

Question

I live in Pennsylvania and the pond temperature will flucuate from a nice summer day to a bitterly cold winter. The pond does have a pump and fountain so the water is circulating. But the amount of algae is clogging the pump too often. Thanks for any and all advice.

Answer 1

Is your algae the free floating type or the attached (blanket weed) type? If it's frre floating, a UV sterilizer can help, but these tend to be expensive and you need to replace the lamps frequently (at least yearly). Fish and snails won't be a lot of help with this type.

If you've got an attached algae, fish or snails will be more useful, but they may not survive over your winter. A UV unit will reduce the reproduction, but it can't do anything for the algae that's already growing.

There are a few things you can try. The first is to control the nutrients in your pond. Don't allow any leaves or other debris to stay in the pond - get them out when you first notice them - these will eventually decompose and add to the nitrates and phosphates in the pond, which become alge fertilizer. If you have pond plants, don't use any fertilizer until they're actively growing and then, only use the pellets that you put right at the plant roots to target the plants you want in the pond. If you've got fish, be sure you aren't over feeding them. All this builds up in the pond to feed the algae. Pond plants will also absorb some of these nutrients, but until they start growing in your climate, you can reduce the amount by doing a partial water change (around 25%) with a siphon, just like your pond was an aquarium - at least if your pond is a practical size to do this. You may need to repeat this on a regular basis. This will also reduce the amount of algae, if you have the free-floating type.

Algae also needs light to grow. Once it gets warm enough, using floating plants (water hyacinths or water lettuce) or plants with floating leaves (water lily) will shade the algae to keep it from being able to use photosynthesis to make food.

If you've got attached algae, you should try to scrape as much as you can by hand and remove it from the pond altogether. If you leave it after you scrape it off, it will decay and add to the nutrients and use up oxygen as it decays, and this can have an effect on any fish you might have in the pond.

Once you've gotten as much out as you can, visit a local pond/garden center and see if you can find barley straw. This can help prevent new algae. See info on this, plus some other ideas on pond algae control from the links I'll post below.

Answer 2

Large apple snails will eat away your algae, but they might harm your fish if your fish end up in a compromising position, such as temporarily stuck. Plecostomus can be added when the water is warm, such as low 70's and higher, but they have to be removed when the temperature drops. Rosy Barbs will take care of hair algae and many other types.

Before adding any non-pond specific fish, you should read up on them and determine if you're willing to acclimise them to your pond, and pull them out if the conditions are too much for them.

If you decide to add algae remover, it might be best for the health of your fish to remove them and any invertebrates, as it might harm them, and the invertebrates will rot in your pond, raising the ammonia levels.

Answer 3

If the water is clear but the algae is growing on things then algae eaters are the way to go. I never recommend chemicals if you can at all avoid it. If the water is green itself then get yourself a u/v sterilizer. It doesn't work well on algae that growns on stuff but it works wonders on free-floating algae. They cost about $125 depending on the size of your tank but are well worth the money. Hope this helps!

Answer 4

Apple/mystery snails would work on that algae. They won't eat your fish, that is rediculous. Have you ever seen how fast a snail is? Any fish eaten by a snail was dead to begin with.

Answer 5

go buy some pond clear or algae remover its not the proper way but it works

Answer 6

mystery snails - $1.99, pleco - $4.99 - $6.99