# RO/DI Float Valve



## PolarisFx (Feb 1, 2016)

Haven't made this yet, I'm just wondering what other people think of this idea.

My RO setup didn't come with an auto-shutoff and so I've been looking at options and it seems no matter what I'm going to spend $60 on a float valve with an auto-off, either by getting one from BRS and paying exchange/shipping or buying one from ReefSupplies and paying shipping.

This is an expensive hobby as it is, and for something so simple I think a DIY option would be far superior. I found a Normally Closed Solenoid with 1/4" push fittings on eBay for $12 and a wired float sensor off amazon for like $3.

This way when the float valve detects a drop in water it will engage the solenoid and allow water into the RO/DI unit, and when full instead of waiting for pressure to build up and engage the shutoff, it will just turn off the water to the RO/DI directly.

What do you guys think?


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## renesis (Nov 17, 2014)

It could work. The only potential issue I see with wiring it directly is when the float switch is at its transition point, it may bounce a bit and turn the solenoid on/off several times. Usually circuits like this have a small microcontroller in between to debounce the switch and give it a bit of a delay once it detects a state change. Without the debounce, the solenoid wears faster and is more prone to getting stuck (open or closed).

Cheaper (and more local) source for the Float switch and ASO are Max Water in Vaughan.

ASO : http://www.maxwaterflow.com/Auto-Shut-off-Valve_c_1317.html
Float: http://www.maxwaterflow.com/Float-Valves_c_1316.html

I've also seen smaller float valves at Princess Auto (1/4") in the surplus section, around $12 IIRC.

Hope this helps,

Edit: Forgot the check valve: http://www.maxwaterflow.com/Reverse-Osmosis-inline-Check-Valve-14-Tube-x-14-Tube-_p_303.html


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