Question about ro/di and ATO

gobytron · #1 05-13-2010, 08:02 PM

I'm finally moving away from the aquarium pharmeceuticals tap waer ro/di filter and setting up an automated freshwater top off system.

I use a tunze osmolator but I am going to be setting up a kent float valve hooked up to a 3 or 4 stage ro/di filter.

My question is aside from the ato, the float valve and the filter itself, what other component do I need?

will any ro/di work or do I need to purchase one specifically set up for an automatic top off system?

Links and advice greatly appreciated.
Thank you.

DiverDude · #2 05-13-2010, 08:56 PM

You need to be careful as not all RO/DI systems can work with a float valve. The valve just builds back pressure which not all systems can handle.

Just be sure to tell anyone selling you a system that you want it to run unattended on a float valve.

gobytron · #3 05-13-2010, 08:57 PM

i was under the impression that a check valve of sorts was attainable to add on to counteract the back pressure?

was I misled?

Thank you very much for the advice.

hillegom · #4 05-14-2010, 12:43 AM

You should look into getting a solenoid to positively close the RO. It could use the information from your float valve when to I/O.

wisesam · #5 05-14-2010, 12:59 AM

I run my RO/DI directly to my tank with a float valve and auto shut off valve.
There is no problem so far.

Milad · #6 05-14-2010, 02:12 AM

i think you need the automatic shut off valve at least
http://www.aquasafecanada.com/aquasafes.html
scroll down half way

i just ordered one, the link above is local to you.

Milad · #7 05-14-2010, 02:13 AM

cheaper one on this site but its far away
http://www.autotopoff.com/misc/

wisesam · #8 05-14-2010, 02:27 AM

I got a spare aut shut off valve.
pm me if you need it.

mike31154 · #9 05-14-2010, 03:26 PM

When setting this up try to ensure the RO/DI system runs for a reasonable length of time to fill a reservoir for top off. Many folks use a single float valve feeding directly into the sump and the system switches every few minutes which is not a good way to run your RO/DI. It generally takes several minutes for the RO/DI TDS to drop to optimum level after the system is pressurized, so if your unit switches every few minutes, you'll have major TDS issues with your top off water. Furthermore, the excess TDS going to the DI in that first minute or so, will ensure your DI media is used up in short order.

Automation can be a wonderful thing and I have the auto shutoff valve on my system, but I still make RO/DI water by manually switching the source on and making at least 5 gallons at a time. I bypass the DI stage for the first minute and send that production water to my RO jug for drinking water. I've never been able to get my auto shutoff valve to work consistently or reliably and do not trust the things. I collect my waste water in large containers to use around the house & garden and do not wish to take the chance of a flood in the event of an auto shutoff valve malfunction. As for electrical solenoids, also wonderful devices, but more electrics involved (increased complexity) and simply another possible point of failure.