How to Keep Mosquitoes Out of Rain Barrels

Mosquito PreventionMosquitoes need water to lay eggs and grow. Without proper prevention measures, rain barrels can become a breeding ground (so can kids' pools, buckets, and puddles, by the way!). Luckily, there are easy ways to keep mosquitos out of rain barrels. Read on to learn how to mosquito-proof your rain tanks or barrels.

It's one of our most frequently asked questions: How do I keep mosquitoes out of my rain barrels?


We'll start with the Don'ts just to illustrate the problem. Be sure to read to the bottom for the Dos!


Don't Do This (unless you want a mosquito problem):

  • Don't use open-top barrels
  • Don't use barrels with contoured tops that trap standing water
  • Don't leave any openings unscreened (even a closed-top "tight-head" barrel is vulnerable to mosquitoes if you consider open vents, inlets, outlets, or overflow ports).
Molded Top Rain Barrels

(Photo credit: San Gabriel Valley Mosquito and Vector Control District)

Pre-Fab Pitfalls: Watch out for decorative pre-fab rain barrels. If the barrel-top has concave features, water will pool on top. These depressions will hold enough water for mosquitoes to lay eggs and breed, despite any effort to keep mosquitoes out of the barrel itself.

Screen Shot 2019-09-09 at 1.07.23 PM

(Photo credit: San Gabriel Valley Mosquito and Vector Control District)

DIY-er's Demise: Even though these barrels are closed on top, the rimmed lids allow water to pool , sending a loud invitation for mosquitoes and their friends.

Screen Shot 2019-09-09 at 1.07.33 PM

(Photo credit: San Gabriel Valley Mosquito and Vector Control District)

Large mesh = Larvae: Large-mesh screens and perforated tops will not keep mosquitoes out. The openings are way too big.

What about lining an open-top barrel with screen?

Screened open-top rain barrelYou guessed it... DON'T. This is a common solution. While it will be effective in preventing mosquito breeding (if held secure at all times, and replaced when worn or torn), it won't exclude sunlight, so you may still end up with an algae problem. If barrels don't have a properly-placed overflow to direct excess water, stored water will rise above the level of the screen, which will make it immediately ineffective in keeping mosquitoes at bay. Fiberglass mesh is commonly used, and is vulnerable to tearing, especially with exposure to weather.

Do it the Right Way!

How to Keep Mosquitoes out of Rain Barrels

Preventing mosquitoes in rain barrels comes down to two basic factors:

  • Keeping water from pooling in exposed places
  • Keeping stored water fully concealed, screening all openings with 1/16" mesh

Here's how we do it at BlueBarrel. Our BlueBarrel Rainwater Catchment Systems prevent mosquito breeding by design. Here are the key features that will keep mosquitoes out.


1. Closed-Barrel Design

Dean's BlueBarrel Rainwater Catchment System

BlueBarrel's unique underplumbed design has many advantages. One of them is full system drainage, so there won't be a pool of inaccessible murky water in the bottom of your barrels after irrigation season is over. The bottom-tapped design allows for particulates to flush through constantly, keeping your stored water quite clean, and accessible to the last drop.

Beyond that, there is no place for mosquitoes to get in. By using tight-head drums (the kind with no removable lid), stored water stays cool and protected.

Our drums are UV-resistant as well, which also keeps the water algae-free. (Algae needs sunlight to grow).

2. Screened OpeningsBlueBarrel Vent Piece

Best practices (and local codes, where applicable), require 1/16" mesh covering all openings on a rainwater catchment system. While this helps to keep debris of any kind out of a rainwater catchment system, the main reason for this requirement is to prevent mosquitoes from entering that are large enough to breed or lay eggs. Each BlueBarrel RainKit comes with inlet screening, and specialty screened vent pieces. This allows for proper inflow, ventilation, and outflow, while keeping pesky critters at bay.


Check out these photos for more examples of a mosquito-proof design. Once you make sure you're taking the proper precautions to keep mosquitoes out of your rain barrels, harvest away!

Steve's BlueBarrel System
BlueBarrel Rainwater Catchment System Santa Rosa
This diverter is installed with a descending inlet hose to force system overflow through the other diverter.
BlueBarrel System at WCU
BlueBarrel Rainwater Catchment System


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