Would this work!

[Prock1]

I want to make a automatic top off, with two float switches and a silanoid, the first float witch will open the silanoid on and off the second float switch will shut the silanoid off completly in case of a malfunction, im goint directly from the ro unit to the sump. Does anybody know if this will mess up my ro unit, and or is this works does someone sell something like this. Dont have any room for a water resavoir

 

[noahm]

Try here. Pretty much have exactly what you need. I have the 2 float switch ATO on my sump, and a solenoid valve with a wide angle float switch for my RO tank.

http://autotopoff.com/

 

[reefergeorge]

The only bad thing is that ro filters aren't very efficient when run in very short periods. So you may be going through di resin fast.

You will also need an auto shut off on your system.
http://www.thefilterguys.biz/ro_di_add-ons.htm

 

[Prock1]

Thank u much

 

[noahm]

<a href=showthread.php?s=&postid=15426799#post15426799 target=_blank>Originally posted</a> by reefergeorge
The only bad thing is that ro filters aren't very efficient when run in very short periods. So you may be going through di resin fast.

You will also need an auto shut off on your system.
http://www.thefilterguys.biz/ro_di_add-ons.htm

That is what the wide angle float switch is for. It lets the level drop however much you adjust it before kicking the solenoid valve on. Mine is set to drop the reservoir to about 1/3 full before filling it back up.