If you are installing the tank yourself, it's vital that you carefully read the manufacturers installation and maintenance instructions.
A tank full of water is extremely heavy and a poorly maintained base beneath it can result in it failing and needing repair – which won't be covered under your manufacturer's warranty. Correct preparation will result in years of trouble-free performance from your tank. If in doubt, involve a specialist.
All water tanks can slowly build up a layer of sludge in the bottom.
This is caused by dust and debris entering the tank and will happen no matter how effective your filtering system is. As a general rule, check your tank for sludge every two to three years. However in Metropolitan areas there are other factors that need to be considered to ensure that the rainwater you harvest can be used to its full potential. For example, your roof is more likely to collect heavy metals from the pollution in the air so a 20 litre first flush device on each downpipe into the tank, sieves, and gutter maintenance are essential. It's much better not to disturb the sludge, it can be a natural biofilter but once the build up begins to effect water quality, consider getting the tank professionally serviced and then let the water settle for a few weeks before using.
No matter how tough your tank is it may, at some time, receive an unexpected impact.
Sometimes, accidents happen: a vehicle might back into your tank, it could be incorrectly installed, or there may be manufacturing flaws that need to be repaired. It is important that a damaged tank is repaired by qualified and experienced contractors to ensure that your tank remains safe and watertight. Ask your agent or manufacturer for a recommended repairer.