How to Clean Sludge Out of a Rainwater Tank

How to Clean Sludge Out of a Rainwater Tank

As part of proper tank maintenance procedures, it is often advised that tanks being inspected inside for sediment build-up at least every two years. This article examines tank sludge, how it gets in your tank and more importantly how you can clean it out should you find it in the bottom of your tank.

What is “Sludge”?

Before discussing how to remove sludge from your tank, you might be wondering what “sludge” is?

If you harvest rainwater, then even with water diverters and appropriate tank screening, organic material and sediments will find their way into your water tank. Over the course of a few years, biofilms develop in your tank which result in a layer of “sludge” settling at the bottom of your tank.

Why Clean Out Tank Sludge?

This sludge layer can accumulate heavy metals such as lead, while also acting as a breeding ground for bacteria and microorganisms. For this reason, sludge is often considered a source of water contamination – it is recommended by Health Departments that your tank be inspected every 2–3 years and built-up sediment cleaned out.

Despite these recommendations, there is controversy over whether sludge acts a source of water contamination or instead acts as a natural water purifying effect by absorbing harmful particles from the water column. Regardless of who is right, we will presume you want the sludge gone and so look at some available cleaning options.

Tank Cleaning Options

There are local tank cleaning businesses around that can be hired to come out and clean your tank. Normally they come with a truck carrying a storage tank, and basically pump out all your tank sludge and dirty water into their storage tank. It isn’t too complicated, relatively quick since they have all the right equipment.

Our recommendation would be to buy and install an automatic tank cleaning system. TankVac is a unique tank cleaning system with no movable parts. It operates automatically without the need for power. Once installed it requires no further work on your part – it will automatically pump out any sediment in your tank through the tank overflow always keeping your tank clean.

Thankfully, TankVac is very easy to install and can be fitted by any DIY handyman. While best to install with a new water tank, if you have an existing tank then it can be retro-fitted even while your tank is full of rainwater. Installing this automatic cleaning solution means you won’t need to worry about sediment build-up in your tank ever again.

The system is very affordable and found at a retail price of around $350, which beats needing to hire a professional every few years or purchasing expensive specialised equipment that will receive very little use. If interested, please inquire with National Poly Industries who sell the TankVac system as an optional tank accessory at a very competitive price.