I've had my backyard re-landscaped into a bi-level garden space. On the lower level is a built-in waterfall that holds approximately 75-100 gal. of water spilling over a stacked slate background into the reservoir below. The reservoir holds the pump and lighting that is directed up to illuminate the stacked-slate backdrop from below. My concern is this: When we turn the waterfall off at night, it can allow mosquitoes to breed in the water that is then, still. Can someone steer me towards a chemical or preferably, something "natural" that can be added to the water that would kill any mosquito larvae and/or repel mosquitoes and not damage the pump submerged below?
Have you any fish or wildlife in your garden pond? If you have then I don't think you'll need to worry yourself too much about the mosquito larvae as the majority of them will get eaten before they get a chance to mature and develop into adults. Even other insects in the water will feed on the larvae.
We have had great luck with Mosquito Barrier, available online. You mix it with water and spray it around your yard and it really forms a barrier against mosquitos. I don't know what it would do if mixed in the pond, but you essentially would be keeping mosquitos away anyway. Its organic -- mostly garlic, so no chemicals. It does produce a heavy garlic smell for a day, but then goes away and lasts about 3-4 weeks. Otherwise, I wonder if a few drops of bleach in the pond would work?
May I ask why do you have to turn the pump off at nite? I have a pump that sprays water up-I leave it going all throught the nite. As Eileen mentioned if you have fish or frogs they would eat any larvae. I don't use chemicals with fish and frogs. I myself don't recomend it only because I think a pond is better if its all natural but thats only my opinon.
Petunia that is what I was going to ask! I have never had a water feature, but why do they have to be turned off? To save electricity or what? Seems like it would be good for the pump to keep it going! Oh I don't know ...
outdoor fountain and mosquitos No, I don't have fish or anything "live" in the water fall. I wouldn't consider putting chemicals in the water if that were the case. Presently, I do put some bleach in the water, but I don't know if common household bleach will eventually adversely affect the pump, that's why I'm asking if anyone knows of a product that is specifically for man-made ponds/pools/fountains/waterfalls, etc. I figure that all of those applications deal with water and pumps so maybe a product used in one is good for all (quantity of product used depending on water volume,of course) I will research pool/pond supplies. We turn the fountain off at night as one of many energy saving measures and because (although I can't imagine anyone complaining) the waterfall is quite loud and can be heard throughout my house (4 floors).
You could use mosquito dunks. But, I don't know how you will keep the dunks from falling from the top reservoir. They are available at most hardware and lumber stores. I believe they make a granule version too, but I don't know if that would gum up your pump.
A very good remedy is sulphate of copper. Just add a little (one tablespoon) to the water and everything will be killed. I know this because I have a big aquarium and had some similar troubles.
I kept my fountain pump on all the time back in the U.S. But in standing water, I used Mosquito Dunks (a biological mosquito control) because they do not harm birds or fish. Once frogs and lizards found their way to my water, I no longer needed the dunks. It has worked the same way here in Kuwait. When mosquitos started entering my outdoor gardens, I placed a little piece (instructions on how much to use are on the back of the paper) wherever I had standing water. (As in planter drip trays.) They controlled the mosquitoes until the birds and lizards found my gardens. Until I used the dunks, I tried all sorts of other ways to rid the area of mosquitoes (except for poisons) and this was the only one that worked. It does take a little bit of time as it kills the larvae not the adults. Good luck! I wish I had a waterfall here!
