Tired of accidentally leaving the water on?

[AllSignsPointToFish]

I have a DIY solution that I just implemented to prevent the accidental overfilling of DI water containers. If you're like me, you've left the water on and overfilled the container...more than once! Even if the water is contained by a sink and doesn't make a huge mess, you still end up putting perfectly good deionized water down the drain, not the mention wasting deionizing resin. I don't know about you, but I HATE going through all of that trouble to make high purity water only to waste it!

So, I came up with a simple solution to the problem. The total cost of parts is around $20 if you buy them on Amazon. You will need the following:
1- 12V, 500mA power supply (https://www.amazon.com/KEYWANTS-Sup...1-spons&keywords=12v+500ma+power+supply&psc=1)
1- 12V, 4.8W solenoid valve with 1/4" tubing ends (https://www.amazon.com/gp/product/B016MP1HX0/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1)
1- 12V float switch (https://www.amazon.com/gp/product/B01LZ09XPD/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1)

The assembly instructions are pretty simple:
1. Clip the end off of the 12v power supply cable. Solder the positive (red) end to one of the leads on the switch.
2. Solder the other lead of the switch to one of the lugs on the solenoid valve.
3. Solder the negative end of the power supply cord (black) to the other lug on the solenoid valve.
4. Rig up a bracket to hold the float switch in the desired water container. Ensure that the float on the switch is below the top of the container to ensure the switch activated before the water overflows. Mount the switch in the container. I used a piece of leftover starboard plastic that I built my filter sock holder from. I would recommend plastic of some sort to avoid contaminating the DI water with metal ions (if considering a metal bracket) or chemicals that may be in wood (if you're a carpenter).
5. Install the solenoid valve in the water supply line going to your RO/DI unit. Pay attention to the flow arrow on the bottom of the valve to ensure proper solenoid orientation.
6. Plug in the power supply and turn the water on. The water should flow through the solenoid but stop when the float on the switch is pushed to the upper stop position.

I used heat shrink tubing to cover the soldered connections. You can use the same, electrical tape, or liquid PVC tape to provide some insulation over the soldered connections. You could also use spade lug connectors on the solenoid valve if you wanted. I preferred to solder since it is more secure (but certainly not pretty!).

When power is lost, the solenoid valve automatically returns to failure (closed) position. Also, note that the maximum working pressure for the solenoid valve is around 120 psig. If you have higher water supply pressure than that, you will need to source a suitable valve.

While this is no substitute for secondary containment, it should help prevent unwanted waste of DI water.

You can experiment with the float switch style and you will need to rig a mounting bracket for you particular DI water container. If you want to get fancy, you can even order a 2.1mm x 5.5mm female pigtail (https://www.amazon.com/SIM-NAT-5-5m...&sr=8-2&keywords=2.1mm+x+5.5mm+female+pigtail) and solder this to the switch and valve, thereby eliminating the need to clip the end off male end of the 12V power supply.

 

[nerses818]

This is exactly what I needed!

 

[AllSignsPointToFish]

This is exactly what I needed!

Let me know if you need any help. I'll try to post some pictures when I have a little more time.

 

[AllSignsPointToFish]

Alright, here is the unit assembled (minus the power supply):

Here is a compatible 12V power supply:

 

[AllSignsPointToFish]

Closeup of the float switch and mount:

I just place the white disk over the large opening in my 6-gallon water jugs.

 

[AllSignsPointToFish]

Note that the switch can be disassembled for insertion into your custom mounting bracket:

 

[AllSignsPointToFish]

Here is the underside of the solenoid valve. Note the flow arrow right is the center of the valve body (hard to see with my poor photography skillz):

 

[nerses818]

This is extremely helpful thanks

 

[Swoody]

Very nice! Kind of funny as I am sure that you and I are not the only ones that have spilled some water! I have actually got out of bed before thinking I may have left the supply water on! The time I did spill...was watching football! (blamed on NFL!)

 

[rayn]

Awesome idea!

 

[revhtree]

Nice man and thanks for sharing!

 

[Drakonis]

I just use a manual float valve from brs for 14 bucks. lets me run my rodi, walk away, and even if i forget it shuts the rodi off. i have this in my 5 gallon pale used for ATO and my brute 32 gal for mixing i just use a valve to divert which container fills.

 

[Shep]

Great idea!

 

[btltez]

I just use the timer on my iphone. never had a flood yet.

 

[Drakonis]

That sounds like famous last words lol

 

[Ocelaris]

The solenoid is great, I've been looking for that for a long time, and the only ones I saw were expensive ones as part of the booster pump, which won't need. Thanks!

Maybe they have one in 3/8th for a CO2 scrubber like brs was talking about.

 

[Jackcarp]

I just use the timer on my iphone. never had a flood yet.

I use the same and to this point I have forgotten to turn the water off 3 times after my alarm went off. Geesh.

 

[CJR]

For those of us who might be less electronically inclined, I saw this at Lowes the other day and as my RO/DI is outside and runs off a hose this is an inexpensive solution. Has a two hour max however so that's a trade off verses overflowing...

https://www.lowes.com/pd/Orbit-Mechanical-Hose-Faucet-Timer/3686860

 

[lorkhan]

I connected my waterline to a water garden timer and once you know how much time you need i just set and forget. Never have an issue water overflowing since its automatically turn off once the timer expires.

 

[chefjpaul]

Great stuff here