Float valve? Solenoid? Please help.....

[Isozephyr]

Good morning everyone !

Here is my dilemna, I currently have a "Premium Reef Supply" 4 stage RO/DI that I purchased from Premium Aquatics. As far as i know it does not have an automatic top off switch and I am currently manually turning my plumbing on and off to fill a Brute 55g container for water changes/evaporation etc...What I would like to do is some how be able to connect my RO/DI unit directly to my plumbing and start filling the container and at the same time be able to step out of the house or go to bed and not have to worry abt it overflowing. In other words I want my RO/DI to run when I decide, but shut off all on its own when the container if full. I have no idea what I need to make this happen or if it is even possible in the first place but I would definitely appreciate others opinions.

[Boostable]

Iso,

This is certainly possible and doable.... Im actually looking at doing the same thing for my new setup.

Im not at that stage yet, but I can give you an overview of what I have planned to do.

(just thinking about this on the ride home today, so im gonna think out loud so bare with me.)

Plumbing the RO into the home water system is the easy part, so I won't go into that... the control of the system is the key here of course.

You need the ability to shut off the supply at a determined water level. The straight forward approach here is the use of a irrigation solenoid. They are available off/open and off/closed variates. For this use you will want the off/closed unit "more common". Most are rated at 12V 300-800ma, so a simple universal DC transformer will work just fine.

My concern here is that the standard irrigation solenoid may not hold up well to the salty environment of our tanks,(will research this more) so some care needs to be taken as to its location and/or a second can be put in line as well. "more on that later"

The tricky part here is sensing the water level of the tank. There are SEVERAL ways to do this. Float, Pressure, Sensor.

As I have a tendency to over complicate things I will probably lean towards doing something with an IC base controller that allows for some simple data capturing... but anyway..

The simplest is the float method. Which of course just provides an open/closed state based on water levels. This could be a simple configuration with a very low voltage setup using a relay to flip the solenoid.

A Pressure sender can be used exactly the same way and it does just what it sounds like it does. Measures the pressure in your holding tank. Set it where you want it and use it to drive the relay for the solenoid as above.

If you want to get cleaver you can use the water itself as a conductor along with a couple of sensor plates "attached to your holding tank" which will flip the relay and turn off the water when the second sensor plate is reached. There are some disadvantages to this, but its kinda cool.

I will stop there before I run on "more then I have", but I hope that helps in some way....

OOO real quick... as I mentioned above I was considering using a second solenoid in line with the first. Floats stick, solenoids hang... a seconds failsafe is a small price for a little extra insurance... keep that in mind while planning your setup.

Ok, seriously im done now... But will be happy to answer any questions I can.

Jack

[dougc]

I use a Kent float valve and solenoid to shut off my RO/DI. The Kent valve is fairly simple and therefore unlikely to fail catastrophically. Mine is five years old and going strong.

When the container is full, the float valve shuts off, creating back pressure, which shuts off the solenoid. The solenoid shuts off the supply to the RO membrane. Otherwise, the water would continue to run through the membrane into the waste line.

Just Google "Kent RO/DI solenoid" and you will find lots of vendors that carry it.

[Isozephyr]

Ok everyone, here is what the salesman told me was a so called pressure solenoid/automatic shutoff switch that can be connected to my RO/DI...one side has an "in" and "out" the other side just says "tank" now my problem is that I have no idea how this connects. I saw another RO/DI unit yesterday with this connected but it looked like a whole different setup. Anyway, here are the pics of the solenoid and my RO/DI if anyone can give me any feedback on how it connects, I thank you!

http://i24.photobucket.com/albums/c4...r/DSCF1972.jpg

http://i24.photobucket.com/albums/c4...r/DSCF1973.jpg

http://i24.photobucket.com/albums/c4...r/DSCF1970.jpg

http://i24.photobucket.com/albums/c4...r/DSCF1971.jpg