Rainwater harvesting tank: how to know how much water you have
From water butts to large underground tanks: ways to check rainwater levels in the UK and choose a level monitor that fits your setup.
Why the level matters
Collected rainwater is free and ideal for gardens, but only if you know what you have. During a dry summer or a hosepipe ban, knowing how many litres remain helps you decide what to water first.
Small water butts
For a small water butt, use an accessible gauge or a safe visual check. Do not lean over an unsecured opening or enter a tank. A simple float gauge in the lid is usually enough.
Larger and underground tanks
Tanks of several thousand litres — often buried — are harder: lids are heavy, the water is dark, and you should never climb in. A suitable top-mounted monitor can measure the distance to the water; conversion to litres depends on the tank shape and settings, not just the height.
Choosing a monitor
Options to compare include WiFi TLC2502, solar-powered TLC2502-WF-S, LoRa-radio TLC2502P-Lora and TLC2502LS-WL with a separate wireless LCD display. The water range uses Tuya / Smart Life. Depths, wireless ranges, some network requirements and LoRa gateway contents await confirmation; a model name alone does not establish suitability for your tank.
Tell us the tank depth, distance, obstacles and power available so we can check outstanding specifications and installation suitability, including underground use, before recommending a model.
WiseTank delivers free to the UK, usually in 7–15 working days from dispatch in China, with tracking. GBP prices are still being set, so you can reserve free with no obligation on any product page.