As many experienced gardeners know, rainwater is perfect for plants as it’s not only preferred, but far healthier. Actual rainwater has acidic qualities; whereas, tap water is somewhat chalky in nature. To aid plants and achieve the optimal growing conditions, harvesting rainwater, storing it, and keeping it clean is essential.

1. Install a filter

Filters are essential and can be installed at various points in your rainwater collection system. If you are using gutters to filter water down from your roof and into your barrel, then install a filter at the main pipe runoff for water into the collection barrel. This filter will prevent larger particles from entering your collection tank and contaminating the water with their decay.

Another place to put a filter is also right before the water enters the tank. This filter can have a much finer mesh to further reduce the chances of unwanted particles entering your water tank. Make sure to check and clean these filters frequently to prevent buildup and blockages.

2. Empty barrels once a week and clean them

Mosquitoes, bacteria, and other unwanted organisms thrive in standing water, especially that which has been allowed to sit for a period of time. If you are collecting rain water in barrels, it’s essential to empty these barrels out frequently. Once a week the water should be changed out allowing for fresh water to come in and any previous growth that was thriving in the tank to be washed out and taken away.

Emptying these barrels out during winter times or colder temperatures doesn’t have to be done as frequently. You can sometimes allow water to stay in for two or three weeks if the temperatures are low enough as organisms have a much harder time thriving in cold water than warm.

Use bleach to completely kill all microbial growth and even destroy some potential viruses that may have found their way within your tank. Once you’ve completely scrubbed out your barrels with chemicals, make sure to rinse it several times. You’ll need to make sure that all of the strong chemicals are thoroughly washed off before rainwater is collected, or you risk damaging any of your plants with the harsh residual chemicals in the newly collected water.

3. Use oil to prevent mosquitoes

In certain parts of the world mosquitoes do not exist and pose no problem for gardeners collecting rainwater. Unfortunately for the majority of people, they do and quickly breed in stagnant water.

If you have a tank and wish to prevent mosquitoes and other critters from spawning within your collected water, then consider adding a small bit of oil. Oil will float on the surface of the tank, making it so that you can use almost all of the water below without fear of the oil being spread out into your garden. Additionally, the oil will create a film across the top of the tank that acts as a barrier against mosquitoes and prevents them from breeding. This simple tool is highly effective and needs only a tablespoon of oil for most tanks.

4. Add chlorine/iodine tablets

If you are growing a garden with edibles, it is highly recommended that you treat your water for certain waterborne diseases. The two main types of diseases you’ll come into contact with are crypto and giardia. Both of these diseases affect the bowels and you can get them not only by drinking contaminated water, but by eating something that has come into contact with contaminated water.

Washing off your edibles dramatically helps prevent contracting these two diseases; however the best way is to treat your water for it. Simple chlorine and iodine tablets can be placed into rainwater tanks and will not only help with algae control, but can kill both crypto and giardia making the water safe to use and able to be stored adequately.

5. Paint barrels

An interesting and highly effective way to prevent algae and other growth from forming in your tanks is to prevent light from entering completely. Using black or brown paint and painting your barrels can help reduce the light entering. Since algae is a plant and needs light to grow, using a tank with a lid and dark sides can help completely prevent algae from growing without having to treat the water with chemicals or empty it frequently.

Unfortunately painting your barrels does not reduce the growth of mosquitoes and other bacteria. Keep in mind that the dark color also will heat up the tank more as the sunlight will be absorbed. This increased temperature can make the water ideal for mosquitos and other parasites, so consider using oil on the top to prevent their growth as well.

Do you have any tips or tricks for keeping your rainwater clean? Leave us a comment below, and let us know!