How To Manage Your Rainwater Tank System

Rainwater tanks are commonly-used in rural areas to collect clean water to be used for drinking.  But just how clean is the water in your tank?

Here’s how to manage your rainwater tank system to make sure that your drinking water is safe and pure.

Collection surfaces

The water in your tank doesn’t come straight from the sky; it arrives there via a series of collection surfaces.  That means that if those surfaces are covered with chemical spray drift, bird or animal droppings, and leaf debris, all those contaminants will be running straight down into your rainwater tank.  Over time, a sludge will form at the bottom of the tank where potentially harmful microbes will proliferate, leaving you exposed to using dangerous and unsuitable water.

Rainwater collection surfaces generally take the form of roofs and gutters.  Keep all areas that form collection surfaces clean and free from debris.  Make this task a part of your regular monthly maintenance schedule.

Seal the tank

In order to prevent from contaminants entering your tank, it’s important that you take steps to seal it.  Use a leaf catcher basket to stop fallen leaves accumulating where water may run through them and into the tank. 

Make sure that there are no openings where animals could gain entry seeking water, only to fall in and drown.  Fit small-gauge insect netting over the water entry point and any open overflow ports to prevent smaller creatures and breeding mosquitos from getting inside and contaminating the water. 

Remember to check and clean out the netting and the leaf basket at least once each week.  Check the tank itself on a weekly basis to make sure that no dead animals are floating inside.  If you find something nasty in there, you’ll need to empty the tank and clean it out thoroughly.

Chlorinating your water

It’s a good idea to chlorinate your tank regularly to reduce the risk of contamination.  You can buy proprietary rainwater tank cleaning products from good DIY stores, swimming pool suppliers and some large supermarkets.  Your water may have a slightly chemical taste immediately following treatment, but this should pass within a few days.

Water filtration

It’s recommended that you fit a water filtration system to your rainwater tank.  This reduces the risk of harmful microbes or chemicals entering your drinking water.  Make sure that you change the filter cartridges regularly as per the manufacturer’s directions.

First flush diverters

A first flush diverter system installed in your downpipes works by sending the first flush of water following heavy rainfall directly onto the ground or into the drain instead of into the tank.  This prevents debris that’s accumulated during a dry spell from being washed straight into your water tank.  The first flush diverter then resets itself and any subsequent clean rainwater is sent straight into the tank.

Cleaning the tank

You should empty and clean the tank annually.  It’s a good idea to employ a professional company to do the work for you if you don’t like working in confined spaces.

Begin by draining the whole tank.  Remove any sludge that’s accumulated in the bottom of the tank by pumping it out through a hose using a motorised pump.  You can dig the sludge into your garden if you want to – it makes great free compost!

Give the inside of the tank a good swill out using a hosepipe, but don’t scrub away the algae that lines the inside walls.  This green growth is non-harmful and actually helps to purify the water.

In conclusion

A properly-managed and maintained rainwater tank can provide you with a good supply of fresh drinking and cooking water.  Keep your rainwater tank system properly maintained by following these helpful tips.