Looking for DIY auto topoff

[jpsg007]

Looking into building auto topoff for sump using the float switch.

[dngspot]

From a post on my local site
http://wichitaaquariumclub.com/forums/showthread.php?t=599


I have had this sitting around for a time and thought that I might as well finish it.
Today I made the bracket that will hold the float switches. One of the floats will set on top of the other. The way it works is the top float will drop and nothing will happen until the lower float drops then the RO system will start moving water via a solenoid valve. When water raises the lower float nothing happens until the water raises the upper float, then the water is shut off. The switches run on 12 volt DC and the solenoid sees 120 AC.
I made the circuit from parts found at Radio Shack. They consist of a relay, pc board and screw type terminals. Soldering one is pretty easy if you understand the schematic. It took me about 30 minutes.
I have been using a timer, solenoid and float valve to regulate my auto top off. I know that my tank uses about 4 gallons of water, through evaporation, My RO/DI is rated at 200 gpd, and I do not get that much because of water pressure. I know that I make over 5 gallons an hour, so I set the timer to stay on for an half hour in the morning and afternoon. When the water in the sump if full the float shuts off the water. This is not ideal because I still put the RO/DI against the float valve which builds TDS, The new system will shut the system down when the sump is full and not trickle through the float valve as water evaporates.
The bracket and float switch mounts are made from ¼ inch acrylic. I heated them until I could bend, the bracket was bent into an upside down channel, and the mounts are bent into an L.
I also ran the wire needed to the tank and through the basement to the RO/DI. I need to pick up some nylon screws and nuts for the bracket. So I am for the day.
http://www.wichitaaquariumclub.com/photopost/data/500/medium/Float_Circuit.JPG
http://www.wichitaaquariumclub.com/photopost/data/500/medium/Auto_Top_Off_1.JPG
http://www.wichitaaquariumclub.com/photopost/data/500/medium/PC_board.JPG

[Gtstricky]

They sell components (and kits) here: http://www.aquahub.com/store/autotopoffcomp.html

[jpsg007]

Great, for now I plan to hook up 5 gallon reservoir to the auto topoff.
I also like the idea of hooking up RO/DI using solenoid valve.

[MeuserReef]

These might help you along:

How to wire the relay, floats, and pump/solenoid/doser:
http://img.photobucket.com/albums/v708/Original_Tarheel/Diagrams%20and%20Schematics/ATOWiringDiagram.jpg





Heres my ATO setup that controls my RO/DI directly.
http://img.photobucket.com/albums/v708/Original_Tarheel/ROAutoTopOffSchematic.jpg

[jpsg007]

So the timer acts as a backup in case the solenoid or relay fails?

[MeuserReef]

Exactly. The timer controls the total minues per day that the ATO can receive electricity. I did this because I dose all of my RO water through a kalk reactor, which will spike the pH of the tank if dosed in large quantities. I top for 15 min, 5 times per day to help keep the pH as stable as possible.

This setup really should also have a mechanical float in the sump to prevent the sump from overflowing should the solenoids both become stuck open (which would still allow water to flow into the sump, even during the off cycle on the timer :( )

[jpsg007]

Thats why I am little scared hooking up RO/DI directly to the sump.

[MeuserReef]

If planned properly, its no more risky than the Ice Machine in your refrigerator.

[jpsg007]

It never occured to me that ice machine has solenoid valve.