Prevent Pond Scum Prevent Mosquitoes
We get so many questions about ponds and mosquitoes that I thought the onset of warmer weather would be a good time to say a little more on the subject, and add a little refresher course. If this looks like something you have read on this site before, it is because it is in part. We have included links to related topics at the bottom of this article.
We have noticed that the number of mosquito questions regarding their presence in and near ponds happens in direct proportion to the numbers of pond scum questions, and often in the same sentence. It is not a coincidence. Pond scum provides the perfect atmosphere for breeding mosquitoes.
Insecticides
Questions regarding the use of insecticides in ponds mean that most people are looking for a way to patch the situation up, but not fix the problem. At any rate, the right kind of insecticide to use in a pond is none! Insecticides work on the nervous systems of the pests they are designed to kill. The nervous system of fish and the creatures that fish eat, are only slightly more advanced than that of insects. Insecticides in water kill fish!
Preventing pond scum
The best way to get rid of the mosquitoes is to prevent them by getting rid of the pond scum, and keeping it from coming back. The best way to do this is to prevent it to begin with.
Limiting sunlight
This requires preventing sunlight from penetrating to the bottom of the pond, and can be accomplished by increasing the waters depth by either raising the water level, or digging out the bottom to make it deeper.
Raising water levels
Raising the water level is only possible if the dam of the pond is high enough and strong enough to allow this. Please check this before adding a section on to your overflow pipe, or raising the spillway area. A single problem in this area could destroy your pond.
Making the pond deeper
Dredging is an option, but often an expensive one. Sometimes it can be done by draining the pond and hiring someone with the proper equipment to dig it out. If you do this, try to make the edges at least 3 feet deep.
Coloring the water
Another option for decreasing and preventing pond scum is making sure that the water is properly colored. There are products available that will color the water, and help prevent sunlight penetration. My suggestion is that if one of your purposes for having a pond is having fish, don't use them. These colorants disrupt the natural pond life cycle.
Plankton
To do this right, you should check the depth that light can penetrate your ponds water with a secchi disk. If light penetrates more than 24 inches, the pond needs to have fertilizer added to produce algae bloom. This single cell plankton will color your water a deeper shade of green, and prevent light from reaching the bottom which is where pond scum starts.
Other pond vegetation
This procedure will also help with other unwanted pond vegetation for the same reason. Submersed, and emergent pond weeds start at the bottom. Limiting the depth to which sunlight can penetrate is crucial to preventing them from getting a foot hold.
Resources for mosquitoes and pond scum
The links below will offer further information, some of it already alluded to on this page. We even have information on treating and preventing pond scum with natural products like barley straw, and using more traditional mineral and chemical based treatments.
- Preventing Pond Scum In Farm Ponds
- Lake Management Lake Depth Secchi Disk
- Lake Management Lake Weed Control Water Depth Secchi Depth
- Lake Management | Pond Algae Pond Scum
- Pond And Lake Mosquito Control And Lake Vegetation
- Barley Straw Pond Algae Treatment
