• The first common tank mistake is getting too small a tank, or hooking it up to too small of a roof space.  There are diminishing returns on larger tanks, but for most of our clients who have mains water backup, the sweet spot of tank sizing is usually around the 5,000 litre mark, rather than the commonly seen 1,000 litre tank. That said, even these smaller tanks can be quite useful.
  • The second common tank mistake is squandering fall, or running water down into a tank below the house.  Get the tank inlet as close in height to the gutter output as possible, so you can let gravity get the water where it needs to go (look mum, no pumps!).
  • The third common tank mistake is assuming that the tank has to go right underneath the downpipe.  This is usually an inconvenient place for a tank and there are simple tricks you can use to place the tank out of the way in the back corner, all covered in our main tank article.