Thread: Rainwater tank gauges

You can buy things that do that which become a part of the downpipe. Called first flush or something.

Rainwater Harvesting | First Flush Devices Water Diverters or Roof Washers

This pic has a leaf screen and a first flush before the tank

Yep, they're called water diverters, i used to have one on the house tank on the farm, just haven't got around to rigging one up on the tank on this place yet, and the tank's only been in three years....

As for height, when the pump starts to cavitate I know the water level is low

Screen is all I have. I'm low when the pump shuts off... then its onto bore.

We're lucky here, rainwater for drinking and the sink, river water for everything else.

I pump up from the river to a tank on the hill and gravity feed the house so we still have toilet, shower, etc when the power's off.
It's only a 4.5m fall, but coming down through a 40mm pipe and 3/4" plumbing in the house it works OK.

Easyiest and cheapest method.
Half fill a 2lt Coke bottle with water.Get some heavy fishing line tie it to the neck,feed the end out of the tank overflow.Tie a reasonably heavy weight to the fishing line,needs to be in the less than 500gm range.The gauge will run back to front but will work perfectly,the length of the fishing line needs to be the height of the tank.
Its how I measured my tanks when I lived on a farm.
Andrew