Which Float Valve Is Best for Cisterns and Water Storage Tanks?

Not every storage tank is a rainwater harvesting system. Well backup reserves, emergency water storage, irrigation supply tanks, and general non-potable storage all need level control too — and the right valve depends on what that storage tank is actually supposed to do, not just how big it is.

Standard Full-Service Valves: Keep the Tank Topped Off

If the goal is a cistern that stays full and ready — a primary water source, a reserve you want at maximum capacity at all times — a standard valve is the right tool. Rojo covers smaller storage tanks, while Topaz and Vortex scale up for larger storage and higher-demand systems.

PartFill Valves: Maintain a Minimum Reserve Instead

Some storage tanks aren't meant to stay full — they're meant to hold a minimum reserve as backup while a different primary source does most of the work. This is common with well-fed properties keeping a backup reserve, or pump-fed irrigation storage where the goal is simply preventing the tank from running completely dry rather than keeping it topped off constantly. A PartFill valve is built for exactly this logic — rainwater harvesting is the most common example, but the same principle applies to any tank where "just enough, not full" is the actual goal.

Differential Valves: For Pump-Fed Cisterns

If your storage tank is filled by a pressure-controlled pump, a standard valve can cause the pump to rapid-cycle as the water level hovers near the shut-off point — a common cause of premature pump wear. A Differential valve widens the gap between fill and shut-off specifically to prevent this, letting the pump run in longer, less frequent cycles.

Sizing and Material Considerations

The same rules apply here as any other application: match the valve's flow rate to your actual supply plumbing and demand, and choose corrosion-resistant, UV-stable construction for any tank stored outdoors long-term. A cistern is often a set-and-forget installation more than most — material quality matters more here, not less.

Not Sure Which Fits Your Tank?

Compare the full Jobe lineup or contact us and tell us what your storage tank is actually supposed to do — stay full, hold a reserve, or protect a pump — and we'll help you land on the right valve.