Jobe Rojo vs. Hudson Valve: Which Small Float Valve Should You Buy?

If you're shopping for a compact float valve for a small tank, cistern, or aquaculture setup, two names come up constantly: Jobe's Rojo and the Hudson Valve V-S-G. Both are small, low-flow valves aimed at the same use case, but they solve the problem in genuinely different ways — and that difference matters more than the price tag suggests.

Two Different Ideas of "Automatic"

Rojo is a true float valve: a float arm rides the water's actual surface, and the valve opens or closes based on where that surface sits. It's automatic the same way a toilet tank fill valve is automatic — it's reading the water level directly.

The Hudson V-S-G works differently. It has no float arm and no float ball at all — instead, it's a pressure-actuated diaphragm valve that closes in response to backpressure building in the line as the tank fills. That's a clever, compact design, but it means the valve isn't actually sensing water level — it's inferring it from line pressure. In a system where pressure can vary for reasons unrelated to tank level — multiple fixtures drawing from the same supply, elevation changes, a partially closed valve upstream — that inference can drift from the real water level in the tank.

Flow Rating: A Hard Number vs. a Wide Range

Rojo publishes a specific ceiling: up to 4 GPM on the standard valve, up to 7 GPM on the High-Flow version. You know exactly what you're getting before you buy.

Hudson's spec sheet lists flow as "approximately 80% of the flow supplied to the valve," translating to a published range of roughly 5 to 40 GPM. That's not really a valve spec so much as a description of how the valve behaves relative to whatever's feeding it — your actual flow rate depends entirely on your upstream pressure and pipe size. For anyone trying to size a system precisely, a valve whose real-world output is a moving target is harder to plan around than one with a fixed ceiling.

Serviceability: Built-In vs. Bolted-On

This is where the price difference earns its keep. Rojo includes a built-in check valve, so you can pull it for cleaning or repair without shutting off the main water supply first. It also has a manual lock-off switch for tank maintenance — flip a switch, work on the tank, flip it back.

The Hudson V-S-G has neither feature. Servicing it means removing the strainer cap to inspect the internal passages directly, and there's no built-in way to isolate the valve from the supply line while you work — you shut off the main line yourself. For a valve that, per its own documentation, needs periodic cleaning to prevent sediment and rust from clogging its internal passages, that's a meaningful gap in convenience.

Adjustability

Because Rojo's float physically rides the water surface, you can adjust where it triggers shutoff simply by adjusting the float height — and an arm extension is available if you need a wider adjustment range. The Hudson valve has no float to adjust; its shutoff point is a function of its internal pressure threshold, which isn't something you tune per application.

Price

Hudson's V-S-G typically runs around $29.99. Rojo starts at $40.99 for the 1/2" inlet and $41.99 for 3/4". That's roughly an $11–$12 gap — the cost of a level-sensing mechanism, a built-in check valve, a lock-off switch, and adjustability, versus a simpler design without those.

Which One Fits Your System

If your priority is the lowest up-front cost and your supply pressure is stable and well understood, the Hudson V-S-G's pressure-based design can work fine — it's a proven, widely used valve. But if you want the valve to respond to the water level you actually care about, need to service it without shutting off the whole system, or want the flexibility to fine-tune the shutoff point, Rojo's float-based design and built-in maintenance features are built specifically to cover those gaps.

Not sure Rojo is the right fit for your flow needs? Compare it against Topaz, Megaflow, and Vortex to find the right Jobe valve for your system.