RO unit hooked directly to ATO-Hard on filters?

[ianryd]

My RODI is hooked directly to my ATO. When my water level gets low,the RO kicks on and fills until water level is good again. The RO unit is always pressurized, even when the ATO is off. When the DI is close to depleted, I notice an uptick in TDS for the first minute or 2, before returning to zero. Can this setup be hard on my filters, and cause premature filter failure?

 

[ca1ore]

Frequent cycling of RO will deplete DI resin much more quickly than less frequent cycling. Attaching your ATO to what is essentially an infinite reservoir is generally unwise and frowned upon.

 

[Greg P]

Yes, it can cause premature failure of first your RO membrane followed by quick depletion of your DI media.
RO units are best used by flushing for anywhere from 5 to 20 minutes before keeping the product water. This allows any TDS 'creep' to be flushed away before entering a storage vessel.
I use a flush kit to 'flush' the membrane (watch the TDS drop) before diverting the product water to my drum - or in your case to the DI canister.

 

[ianryd]

So would you suggest I add an inline pressurized RO storage tank (like you see for under sink drinking water units) to lessen the cycles, and flush in between fills? I like my setup because its pretty much set it and forget it, but if it going to burn out my filters I am open to suggestions.

 

[Gtinnel]

If you are using a float valve to turn it on or off then yes the quick cycling on and off will use up your di resin quickly. Also, if completely automated and no means to flush the membrane it will reduce the life of the membrane.
My rodi is also completely automated feeing my ato but I am using float switches so it only kicks on when the container gets low and kicks off when full. But I also have a homemade controller that my father made me that has a series of solenoids that flushes my membrane, then puts the first 2 minutes of water out of the membrane down the drain (to extend my di life), and then after the water flows into the di it dumps the water from it for the first 2 minutes.

 

[ianryd]

My ATO is a Spectrapure unit with a float valve as a fail safe. Essentialy it is a sensor that opens the valve hooked up to the RO line when the water level gets low. I will check their website to see if they have any recommendations