Auto top-off - aqua safe
 

This is for my saltwater mixing rig, not my reef, so double-and-triple failsafes aren't so important.

I have an aqua-safe ro/di. It has an auto shutoff valve (a pressure solenoid?). If I tee off that to a routine float valve, is that sufficient?

I'm reluctant to trust either a float valve or the aquasafe auto shutoff, but I've seen people post that technique...

If I put in a solenoid, is a pressure-only or electrical solenoid preferred?

i REALLY wouldn't hook your RO/DI to your tank. hooking your tank to a continuous water supply can cause nasty problems if a float switch fails.

You could instead set up the RO/DI to a resevoir that holds say 10 gallons, then top off from the resevoir into the tank using something like a tunze osmolator or a JBJ auto top off. cuts your chance of problems down in half...

if the JBJ/tunze top off fails you have only like 10 gallons dumped into the tank. if the RO/DI fails you have water all over the floor but your tank will be ok.

I just make a bi-daily chore of hauling water to my tank's top off resevoir (JBJ auto top off).

I've been running my RO/DI with solenoid shutoff to a $10 Home Depot furnace humidifier for like 5 years now, or more, I can't remember when I first started doing it. The only time I really had an issue with a float valve was due to me trying to push kalk through it, it would clog up every few months and require soaking in vinegar overnight to get it to reopen.

I found that the trick to keeping a safe level in my resevoir is to turn the pressure way down to a trickle so the valve can handle it. In my aquarium auto top-off there is no way to regulate the pressure so I have it on a timer in case the float switch sticks. (which does happen on occasion)

Any recommendations relative to powered or pressure-only solenoids (and where to find them locally)?
Yeah, this isn't for my display, just a mixing station. I'll look at the Tunze/JBJ stuff if I ever get the nerve to auto top-off my main system.

This is the one I use:
http://www.jlaquatics.com/phpstore/s..._ID=ro-kpfshut

Thing is, especially with a mixing station, you're not going to be filling it 24/7, only when you want it. So it's more of a "in case you forget to turn it off right away" thing. Fill the reservoir, let the float valve shut it off so it doesn't spill over, and then when you come check and see that you're done, turn off the water anyhow.

I run float valves on all my tanks off a reservoir that I fill about every 2-3 weeks. The reservoir itself has a float valve and that kicks the RO/DI off using this solenoid when it's full. So I just turn the RO on, let it fill, next day I turn it off when it's done.

Also just a passing thought .. those furnace humidifier float valves run on household pressure which can be anywhere from 60-100 psi. You don't hear of them of failing very often and when you do, you can usually trace it back to "improperly maintained and/or installed", ie. human error. The orifice that the water passes through is extremely small (less than 1mm) so it doesn't take much to hold back water through that hole. The flipside is that because the hole is so small, if there is any particulate in the water, or kalk, it will gum up very easily and then water can't pass though anyhow.

Have a furnace humidifier float valve hooked up to a Aqua-safe unit in my sump for probably over a year and a half.

Now maybe you can tell me I told you so, but figure neither I or anyone else I've heard of, have had their basement flooded from their humidifier and I'm sure there's a lot more furnaces than fish tanks. Any failure I know of is the valve is stuck closed.

reply
 

This should work. I have this exact system running straight to my sump and so far no problems. There are some other issues that this type of system brings that you may not have though of, but I'll save that for another "need to know" time.

Thanks to all so far... next question: Where can one find tees and john guest fittings for the project? I've never seen them anywhere -- but to be honest, I've never looked for them either!