Keep Mosquitoes Out of Your Rain Barrel: Overflow, Screen, Tips & Tricks

Yesterday we highlighted the fact that mosquitoes can transmit nasty diseases, and general steps to eliminate standing water where their larvae grow.  As rain water harvesters, let's get specific:  Don't let mozzies* get to your water!  Our rain barrel design was inspected by an entomologist who said it is good for keeping out mosquitoes---as long as you keep the screened lid on and the overflow connected to its hose or pipe.

If you have a rain barrel or rain tank from Rain Barrels Iowa, it has an overflow: a brass hose adapter, a hose barb for corrugated hose, or a 3-inch or 4-inch diameter PVC, all of which to let extra water out in a controlled fashion when the container is full.  And all of which can let mosquitoes in. From the mosquito's view, still water without predators is an ideal place to lay a few hundred eggs at once!  So, if you haven't properly completed your rain harvest set up with a hose or pipe on the overflow opening, PLEASE DO THIS TODAY.

Please inspect your rain barrel lid and screens. A slightly damaged screen can admit an eager mosquito. We can replace your lid screens at our shop (we have screened many rain barrels from elsewhere, too). If you notice anyone harvesting rain without screening or in open containers, please urge them to "get screened today!"
We often can repair a cracked lid, too. 

Other anti-mosquito tips and tricks:

• Mosquito "dunks" of Bt-israelensis (Bt-i), a biological pesticide said to be non-harmful to humans, pets, wildlife or fish.
• Release a few feeder goldfish into your rain barrel, or rain tank, but in my opinion this is a better solution for an open pond. The rain barrel is safest with the lid on, but I'd want to check on the fish to make sure they are thriving, & probably feed them periodically. Other fish that dine on the larvae are mosquito fish, minnows, koi and guppies,
• Water that stays fresh and in motion with a pump system doesn't attract them as a breeding ground.

What effective anti-mosquito steps are you taking?  Please share your thoughts & experiences to help other rain harvesters!
* "Mozzie" is our Australian friends' term for mosquito

Photo from Photobucket