ATO/RODI Safety Checks

Jgoal55

New member
I know a lot of you plumb your RODI systems straight into your tank with a float switch so that when the tank needs to be topped off, the float switch switches on the RODI and the water goes straight into the sump as opposed to using a reservoir tank of some sort.

My brother is thinking about doing this in his tank to get get rid of his RODI Top Off reservoir so he can have more room under the stand.

However, what safety checks can be put in place in case the float switch fails? Since it's not electrical, a double float switch won't do any good. I'm sure there is something out there.

Thanks for the help.
 

Rogger Castells

New member
Jorge, there is two things that occur to me could be done in that case, one is to add a solenoid to the ro/di unit connected to a float switch in the sump, this will work only if the float valve fails and starts filling the sump with ro/di water. The second one would be adding a salinity probe that give you and alarm or shuts off the solenoid if the salinity goes out of the range.
Having answered your question, I would like to add why I wouldn't do it like that.
First is performance, RO/DI units are more efficient when they have been working continuously for a few minutes, (by efficient I mean water purity) in other words the first minute or so of output the TDO's are usually higher and lowered and stabilized after that.
If you connect the unit so that a float valve in the sump turns it on/off, it will work for a few seconds at the time every hour.
My second concern will be the nature of pressure switches, IMO they are not reliable and always keep a lot of pressure in the lines making them prime candidates for cracks and leaks.
 

AquamanE

New member
This months meeting will have Cliff from AirWaterand Ice as a speaker. Im sure he can help with that question.
 

Jgoal55

New member
Thanks Guys....this would definitely be an interesting question for Cliff....hopefully no hockey that night so I can make that meeting. In particular about how much effectiveness the system loses by running in spurts. It sounds like it would be pretty significant.

I think what I decided to do is to build an acrylic ATO container that fits under the bathroom sink thats right behind the tank. Plumb the RO directly to that sink and plug it into the container and just refill when necessary. That way, no container under the tank and the double float switch provides safety and redundancy.

As for the 7 gallon tank....not enough water volume....we had an 11 and had to fill it up once per week and that was almost too much for my brother. Im going to see if I can build something for under the sink that will hold about 15.
 

mrx66699

New member
+1 Jorge dont do it straight to the top off.....second if you are going to do it under the sink like this and put the rodi hookup to a float switch you are essentially doing the same thing as putting it into the tank its going to go on and off on and off .....lowering your filter lifetime and quality of water as Roger has already stated (+1 dont do it).....

now that being said you can do it like this and fully automate it and accomplish what your wanting if you plumb it correctly and use the correct switches (solenoids) all you have to do is position the switches at a level in the container where they only switch on when its very low and then have another switch shut it off when its almost full (double up the switches if you want redundancy) .....now you get the best of both worlds your not turning it on and off constantly and your allowing it to run at almost maximum efficiency........ the only other thing I would recommend is flushing the ro membrane before you mix water each time if you want to get maximum efficiency.....just set it up with a switch that runs the lines with a timer and another switch so the first 10 minn or so its on the water is being dumped (tap into the sink drain) then a switch switching it back to filling the RODI storage unit after the first few min of flushing.....this is prolly more elaborate than you would like but it is possible, cheep, and will give you maximum efficiency with your RO membranes, DI, and redundancy

if you dont want to fully automate it just flush the ro for a few min once a week and then let it fill and shut it off manually..... I use both of these methods combined at the moment.....I have 150 gal of rodi storage that can fill automatically when low and then I manually control the filling of my rodi top off storage next to the tank when I see its running low
 
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AquamanE

New member
Thanks Guys....this would definitely be an interesting question for Cliff....hopefully no hockey that night so I can make that meeting. In particular about how much effectiveness the system loses by running in spurts. It sounds like it would be pretty significant.

I think what I decided to do is to build an acrylic ATO container that fits under the bathroom sink thats right behind the tank. Plumb the RO directly to that sink and plug it into the container and just refill when necessary. That way, no container under the tank and the double float switch provides safety and redundancy.

As for the 7 gallon tank....not enough water volume....we had an 11 and had to fill it up once per week and that was almost too much for my brother. Im going to see if I can build something for under the sink that will hold about 15.

Jorge- Cliff spoke 2 days ago. :confused: :debi:
 
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