RODI Plumbed Directly To Tank

[djobaekdb]

I am looking to build a ULM tank at some point that is fully automated and I have come across RODI units being plumbed directly to a sump or ATO within the cabinet to eliminate the need for carrying buckets of water. Redundancy of failsafes to ensure flooding the tank as well as your home does not happene is a must, but what are your experiences and tips for doing this successfully?

Plumb to ATO or sump, utilize Apex, float valve, solenoid, etc.?
Slow drip or ATO a few gallons at a time? Any unique parts out there I should be aware of?
Horror stories to make me reconsider ?

Let's hear your thoughts!

 

[jimmyzhou]

Is not that good for membrane and di.. u maybe will get high tds also. Not ready recommend keep on and off

 

[Erica-Renee]

RODI Works best to run it for longer periods of time and now on and off such as using it for ato..

 

[JoshH]

I agree with everything stated above, if you really don't want to carry buckets you can always run a pump and pipes from your mixing station to your ATO and have it run on a switch you can turn on or off yourself. If you see your ATO reservoir running low just flip a switch or turn it on with your phone via apex or GHL and fill it back up. Then when your mixing station gets low you can turn on your RODI and fill it up. Saves LOTS of wear and tear on your membrane and resin and you still achieve your goals

 

[EW_Fish]

Why not just have a larger ATO that is plumbed to your sump? Constant on and off of the RODI is not good for the membranes as stated above.

 

[djobaekdb]

I agree constant on off is bad for the resins. I think smaller tanks could benefit from the RODI filling a 10 gallon reservoir and to about 90% capacity then once depleted to a threshold of ~10% remaining, fill again. Certainly not ideal for the membranes and TDS creep would be inevitable, but still beats carrying buckets. The mixing station with a pump plumbed to the tank would be the best solution, however I do have limited space and would have to plumb to the second floor. Doable, but not easy.

 

[Flippers4pups]

@jimmyzhou is correct. It will reduce the life of your reverse osmosis membrane. The constant on and off also increases the likelihood of total dissolved solids (TDS) getting into your system. That alone is enough to reconsider.

The redundancy needed to insure that there isn't a major flood or failure to keep it filled by directly attaching a RO/DI unit to a ATO Reservoir isn't something, me personally thinks is worth in the long run.

The reasons for not connecting direct to a sump are the same. If a mechanical float valve sticks, major flood and death of your tank. If a solenoid sticks, same. If it sticks closed or there is a power failure, the system SG will rise and or run the sump dry if away for a long time, such as a vacation.

A RO/DI unit with a automatic shut off plumbed into freshwater tank of a good size, with a mechanical float valve and some plumbing with a ball valve into ATO Reservoir is all that is needed.

 

[Meo]

My 0.02

I run one on my tanks with this configuration: a RO/DI reservior under DT filled by a RO/DI system controlled by an apex. Membrane valve on water supply, 1 float switch for start production and 2 float in series for stop. But I run with a timer, so the Max level floats are only for safety. I have too a emergency drainage in the upper part of reservior.

I use a normal ATO (apex ATK) to fill in my tank, when needed.

 

[schprock]

I run directly from R/O unit. I tee off the kitchen drinking water unit. There are two R/O reservoir tanks under the sink. Tank water goes to an extra stage of DI then to two solenoid valve controlled by a spectrapure water pressure sensor. There is also a mechanical float valve at the sump where the RO goes in. The solenoid valve is on an apex timer for 3 mins every 3 hours. There are two float switches in the sump that will send alarm if water level inappropriate and turn off the electrical solenoid that are in series.

In addition there are 4 water leak detectors. One in kitchen and 3 under the tank. 1 GE smart home, 1 apex, 1 mechanical.

TDS creep is still an issue but I don’t have room for a third RO reservoir. The DI resin doesn’t seem to get used up too fast.

Been running this set up for over 10 years with no issue.

 

[MJNTWise]

I do this and its great....But I do use a RO-Buddy...I use 2 SV1 and 2 OP eyes with my apex 16....

I run a RO Buddy, With 2 solenoids. With a 30 sec delay (Apex) the RO Buddy comes on. Then after a 45 sec delay the supply solenoid opens to allow for the flush to do its thing. Then after 60 second delay the RODI Solenoid opens and feeds the sump. The reason I’m doing this is for TDS. I feel the kind of guarantees 0 TDS going into sump.

And I haven't notice the di being used up any more or less from making 30 gallons at a time, What I did before....

Just MY thoughts
Matt