How much rain water is in your tank?
PNEUMATIC WATER LEVEL INDICATOR:
RCT's Pneumatic Water Level Indicator accurately displays the water level in a rainwater tank from 0 to 100% by measuring water pressure.
The kit consists of a dial gauge, a tank probe, a condensate trap, 100 feet of small-diameter hose, and all of the fittings to connect everything together.
The dial gauge must be mounted in a dry location, calibrated to the tank depth (up to 8 feet of water), and zeroed. Pulling a knob at the bottom of the gauge operates an internal air pump that clears any water in the hose and the tank probe. The water in the tank then exerts pressure on the air within the hose and probe in proportion to the water depth, which is displayed on the gauge.
Download the 380kb pdf Installation Guide