Check that your rain barrel is made of quality, food-grade material that is meant to hold water. Other types of water containers cannot be counted on to withstand the water pressure.
Make sure it is set up on leveled blocks, so as to provide a safe spot for draining underneath, and a sturdy base to prevent tipping over.
Always keep your rain barrels covered to prevent children or pets from falling in, and to keep mosquitoes and larvae from reproducing.
Cover the downspout and drainage spots with netting or wire mesh to prevent mosquitoes and debris from getting in your water.
Arrange your freeze proof rain barrel so that the overflow valve is facing away from your home's foundation.
General care and maintenance tips:
Only use rain barrel water on your lawn or garden! (Never for drinking!)
If you have a transparent water barrel, you may want to clean it periodically to get rid of algae buildup. However, algae will not harm your lawn or garden.
Clean your roof and gutters at least once a year to minimize debris in your stored rain water.
If you treat your roof for pests, remember to unhook your rain barrel for 2 weeks to be sure of keeping your water uncontaminated.
Try to drain your rain water barrel on a regular basis to avoid a mosquito breeding ground; ideally less than every 10 days, as that's how long it takes for mosquitoes to breed.
You can use a larvae tablet in your plastic rain barrel as a precautionary measure. These chemicals will not harm your lawn or garden.
Depending on the part of the country you live in, you may want to disconnect your rain barrels in the winter if the temperature drops below freezing on a regular basis. Repeated freezing and thawing of the water in your rain water barrel can weaken the material and cause cracks.
Store your rain barrels upside-down to keep them clean when not in use.