Auto Top-Off Upgrade

[NEWSALT]

I want to upgrade my Auto-Top Off system, but I'm not sure of all the parts I need to get it to work the way I want. First thing to note is that the top-off water reservoir will be above the sump so that water can drain into the sump by gravity when needed. How I want the system to work is like this:

A float switch in the sump will open a solenoid valve(S1)and allow water in the top-off water reservoir to flow by gravity into the sump. When the sump is at the proper level, the solenoid closes and stops the water flow.

Tubing will run from my RO/DI unit to refill the top-off water reservoir. As the water empties in the top-off water reservoir and gets to a "low level", I want to add more RO/DI water to refill the top-off water reservoir. Water will continue to fill the top-off water reservoir until it reaches a "high level" and the RO/DI water stops filling.

I already have the float switch in the sump and I have solenoid valve, S1. What I'm having trouble figuring out is how to control water going into the top-off water reservoir and start refilling at "low level" and stop refilling at "high level".

Can someone help?

Thanks

 

[Jcurry@wesketch]

You can use a simple float valve in your sump with tubing up to your RO container. To fill the RO container you need a dual float switch setup like this one:
http://www.reefgeek.com/equipment/Float_Switches/Level_Controller_w!_Dual_Float_Sensors_by_Reef_Fanatic

I use this one and like it a lot although I use it to control a pump in the RO container instead of a solenoid valve.

Or you can search for Auto top off threads on RC. H2OEng has a really good thread and think Melev also has one. They both did exactly what you want to do.

http://www.melevsreef.com/plumbing/auto_topoff.html

 

[NEWSALT]

I was thinking of getting two horizontal mount liquid level switches from McMaster Carr. These switches can be set for NO (normally open) or NC (normally closed) operation. If you go to McMaster Carr's website, the model no. is 46515K41