How to do Rain water tank cleaning and maintenance, some basic tips.

How to do Rain water tank cleaning and maintenance, some basic tips.

When it comes to rainwater, we tend to spend a large amount of effort and expense filtering and sterilising water. There is generally very little effort put into both maintaining your tank properly and ensuring that its contents are in the best condition for using. Maintaining a rainwater tank is fairly cheap, lengthens the changeover time for filters and also helps keeping water fresher for longer.

I can maintain my water tank?

In the vast majority of circumstances people simply install their tank, let the rain or a bore fill it up and then they use the contents. As it is something that simply sits there and does not move or need power, then as the years pass it simply is forgotten. Its only when the 30cm of disgusting black sludge in the bottom is stirred up by rain, the filters block up and the water tastes terrible that suddenly tank maintenance becomes an issue.

By doing some small tasks every year and making sure that your downpipes are properly set up, then you can at least have a chance of minimising the black (bacteria filled) sludge from building up. The first and easiest step is to regularly check on your tank. Climb the inspection ladder and have a look inside, you may be in for a shock.

Make sure you pay attention to:

  • The level of water, so you don’t run out of water at short notice.
  • The roof, liner, leaf basket and hatches are all in good working order and if anything needs clearing or repair, sort it out early.
  • Make sure there are no insects flying or swimming around. While they may look interesting, its probably not good to have frogs swimming around in your drinking water either.
  • Alive insects and animals are ok, dead ones are dangerous!! We have seen rats, frogs, possums, snakes and many other dead critters floating in a tank which customers had simply no idea were there. Any decomposing dead animal is very dangerous to your health.
  • The clarity of the water and can you see the bottom. In a well maintained tank, you should be able to see the bottom of the tank easily and the bottom should be fairly clear of sludge and debris.

Once you have done this survey of your tank, then carry out some basic maintenance. Do this process at least every 1-2 months, even during summer. You never know when you will get a large rain event and if you haven’t done anything for 6 months then you are going to get a big heap of rubbish and dirty horrible water going into your tank. The basic process is:

  1. Start on the roof, check that the roof is clean and clear of debris. If there are overhanging trees and branches, then clear these away.
  2. Clean your gutters regularly. This is important both for collecting rainwater and for fire prevention. Remember that Eucalypts continue to drop leaves all through summer and especially after a hot spell. If you want to, install gutter guard or mesh, there are also some very cool self cleaning gutter systems out there too.
  3. Check your downpipes and drainage to the tank. Make sure this is clean and clear. If need, flush it out every 12 months. A good idea is to install drain points and a first flush diverter to maximise the runoff quality when it does rain.
  4. Check and clean out the entry box. The downpipes will dump into a leaf basket. This needs to be checked and cleaned our regularly. This can be a contamination point as all the water in the tank passes through this.

Is it possible to clean my water tank?

Even with this maintenance, one of the common things that we get asked about is water tank cleaning and is it possible. Especially towards the end of summer, the water level is getting lower and any built up sediment and material is getting drawn closer to the outlets. This can lead to brown or yellow water or sediment in the water. It can also prematurely block up filters and cause problems with UV units and pumps.

Well the answer is yes you can and yes you should.

???????????????????????????????????????????????????????????????????????????????The Australian Drinking Water Guidelines, published by the federal health department, recommend that along with regular maintenance you should desludge your rainwater tank about every 2-3 years. Even with good practice, you tank will still get a build-up of dust, bird droppings, organic material and other contaminants. Over a period of a couple of years this will build up to a horrible black sludge that settles in the bottom of the tank. While generally settled out on the bottom, this will get stirred up from rainfall events. Most of the time you won’t notice it but it is an ideal place for bacterial build up and contamination of your water.

The next step is how do I get rid of that build-up? Well the first way is to empty the tank, hose and sweep out the bottom of the tank and then let it fill again once the rains fall. The main advantage of this method is that all the sludge is cleaned out and the floor and walls are thoroughly scrubbed. There are two main problems with this:

  • You lose all the water out of the tank and if there is no other sources then you need to time it for rain.
  • To climb into a tank to do this is very dangerous as this is an anaerobic atmosphere in a very dangerous confined space.

To climb into a tank in this way you need to be trained and equipped in confined space operations to carry out the job safely.

Sludge vacuum out

The other method is to vacuum out the sludge from under the clean water in the tank. To do this, Southern’s Water have developed the equipment so that your tank can be cleaned out quickly, safely and thoroughly. The operator does not enter the dangerous interior of the tank and can vacuum the bottom of most sized rainwater tanks from either the inspection hatch or from a lifted roof sheet. The benefits of this method are:

  • There is minimal loss of water during the work, generally we see a drop of 5-15cm of water from the tank depending on the size and amount of material to clean.
  • This can be done at any time during the year. As the majority of the contents are retained in the tank, then if the build up is affecting the water properly it can be cleaned out quickly and then the next rain event will top the tank up again.

As a once off operation, the cleaning of a normal 80-100,000L water tank should take 4-5 hours and should cost around $500. We travel to your home with a fully equipped service vehicle and safely and efficiently clean your tank. With a 2 yearly maintenance operation, you could cut this time down a fair bit as there is much less build up so you will lose less water and save a few dollars in the process. As a heavy build up has usually also blocked up the house filters and fouled the UV steriliser, then it is also a good practice to change the filters, check over and service the UV steriliser and chlorinate your pipework. If you don’t have any water treatment for you house water, then we can also recommend and install a quality filtration and sterilising system onto your house water.

Call the team at Southern’s Water today to discuss the health of your rainwater tank and how we can assist you in keeping your water fresh and you family healthy. You can email us or call the shop on (08) 9721 3577.