[Mangrove]

Someone drop me some links for auto-top-off devices? DIY (if relatively easy.. ) and/or commercial is fine if cheap. Post pics of your if you can...

[mbarta]

Do a search on Ebay for "dosing pumps" thats where I got mine.

Mine is this one: Dosing Pump

I paid about $60 for it.

[scubadude]

Kent float valve


and a clean trash can, of course im assuming you already have an RO unit, and you may need some miscellaneous fittings and your set.

[Ltspd]

Float Switch, Ice Cube relay, Solenoid and a ro/di unit. I never ever have to make water to fill any container and the tank always stayed exact. Float switch activates the relay which energizes the 120vac solenoid which opens the RO/DI unit which feeds directly into the sump or tank. Very simple and very effective. Mine has ran flawless for over 1-1/2 years.

Had it on my old setup and just wired up a temp on my temp tank.

[PerryinCA]

I got the spectra pure auto topoff, and it kicks @$$. I would recommend it highly. Its got a pressure activated solenoid that stops all water flow, and has a back up float valve that will stop clean water from entering the tank should the solenoid malfunction (which I can't see happening).

-Perry

[scubadude]

If you dont have a reservoir your really defeating the purpose of a RO Unit....if you connect your RO directly to a float/solenoid that controls your sump level top off levels then what you end up getting is an On/Off activation/deactivation of your RO unit which does NOT allow optimizing process of an RO, atleast IMO :-)

[Ltspd]

Originally posted by scubadude
If you dont have a reservoir your really defeating the purpose of a RO Unit....if you connect your RO directly to a float/solenoid that controls your sump level top off levels then what you end up getting is an On/Off activation/deactivation of your RO unit which does NOT allow optimizing process of an RO, atleast IMO :-)

That question was raised on reefcentral I think and posed to Bryan at Aquarium Water Systems and he disagreed with your statement. He said in his opinion there was no ill effect to stoping and starting the unit and you got no benifit in letting it run for a few minutes before using the water UNLESS it had set up for a long period of time. In my situation it never sat up for any length of time because it always covered evap.

I never had any water related problems in my tank. When the water was checked for Phos and or TDS there was never any. It works very well for me and was 1 less hassle I had to deal with on tank maintance

[scubadude]

that may be true....I thought otherwise though paul....but allow me to play the devils advocate here for a min....what about on and off constantly of the solenoid and the wear and tear that has got to have? are these solenoids made to put up with that kind of abuse?

[Ltspd]

Yes, thats what a industrial solenoid is used for, continual on/off cycles. I think I gave about 30 bucks for a 120vac solenoid out of www.mcmaster.com You are able to use brass/bronze because its BEFORE the ro/di unit (same as your copper pipes)

The secrect IMO behind the whole system is the relay, which handles the amps of a 120 household circuit and keeps both the float switch and soleniod seeing the correct voltage/amprage. The reason I say this is because several years ago I had a polypro solenoid that was cheap (about 15) and wired direct into the float switch without a relay, the solenoid only lasted a few months.

I have approx 55 bucks in the whole setup.

But, this isnt something for everyone.

On another note, if I could find a resonable priced solenoid that was SS and large enough to work in a sump pump situation I would use one there. Problem is a 1" or larger SS version are several hundred for a decent one. This would solve the backflow problems on power outages acting as a stable check valve.

I do use both relay's and solenoids in several other applications on my tank, or should I say suto-tank-in-cogneato-soon-to-be-once-was

[geo]

Originally posted by scubadude
what about on and off constantly of the solenoid and the wear and tear that has got to have? are these solenoids made to put up with that kind of abuse?

FWIW mine has been going a little over 5 years now (knocking on the fake wood computer stand). Its an old kent RO. I was really un aware of the on off affects to the ro water quality. I have never tested it, but never thought i had a reason to. It would seem to me that many times on a day would be ok, but what do i know

[scubadude]

Ok i pulled a thread for reference

http://www.reefcentral.com/vbulletin...threadid=62704

basically alot of ppl had tested this theory and notice a jump in TDS but it hasnt been drastic, Bryan Crenshaw from ARS stated that the main thing that needs to be applied here is that you need to make sure you have 60psi to your RO/DI unit to make sure it runs effeciently and the on/off cycle sholdnt make that much of a difference.

[geo]

I do run mine like that. Anyone thinking about setting up a top off this way should consider the possibility of the float valve failing and flooding the sump with FW. It would be much safer to do it like Rockey and fill a small reservoir with RO water and let the FV operate with gravity.