Kessil

RODI newbie question

Klems

Klems

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Just got one if the BRS 7 stage systems they had on sale during their black friday sale...tried it out (only the sediment,carbon and RO portion) using the garden hose and got 6tds out of product line...before it enters the DI stages. Is that good, or should it be lower? I do not have a water softener yet, do I need one? How quickly will the DI resin deplete?

TIA
 
That’s ok. Shouldn’t use up di too fast.
Normal depends on your tds in and pressure. Do you have a pressure gauge? Have you checked tds in?
Membrane is usually rated for like 97-98% rejection under ideal conditions. Warm water and high pressure.
You could probably get it lower and that would make di last longer.
 
That doesn't sound too obnoxious, but if you assume a 97% rejection rate, that'd translate to 200 TDS going into the system which is not bad at all. But like (the other) Mike said, that's based on ideal conditions, so if you end up having lower TDS going in it wouldn't surprise me either.

What's the TDS going into the system like?
 
The biggest RO cost for new users is the cost of replacing the floor in your house because you didn't buy the automatic shutoff or run your unit in an unfinished garage/bathtub/whatever.
The second biggest is the actual unit. third is the DI and other filters.
6 TDS coming out of the membrane sounds typical. As above, check it at different points in the system.
Consider getting a chlorine test so you can tell when your carbon blocks go instead of just guessing, although most people go with the guess method and I don't hear too many complaints.

How much product water do you/do you plan to use? When I was going through 400+ gallons/week in product water I had all sorts of concerns. Now that I go through about 5 most of those concerns are just noise.
 
Related question for the group here... i have UV as last stage on my in house unit. But when I run UV, the water stinks and tastes like onions if left over night.

Disabling UV with no other change avoids this issue. Any ideas?

I suspect the UV is causing a reaction or creating a condition with the water that remains inside the unit. I have a couple of theories but would love to hear other's thoughts and experiences.

My suspicion is that some of the bacteria that maybe in the water is making it through past the RO membrane, and l then the UV breaks down some bacterial byproduct like dimethyl disulfide as a light based reaction.

If I run UV as last stage, the TDS climbs over night from 4 ppm to like 15 - 30 ppm.

Tempted to put the UV either before the RO or between the RO and last stage carbon polishing filter.

Thoughts?
 
1) If I read that correctly you have carbon after your RO?
2) Bacteria won’t pass through an RO membrane, although dissolved gasses will. Doesn’t mean there aren’t already bacteria there, but I doubt they are going through the RO.

I wonder if you have something living inside the UV unit that gets killed off when you turn it on?
A system diagram would help, I’m a bit confused as to where and why you have a UV unit.
 
Klems said:
Just got one if the BRS 7 stage systems they had on sale during their black friday sale...tried it out (only the sediment,carbon and RO portion) using the garden hose and got 6tds out of product line...before it enters the DI stages. Is that good, or should it be lower? I do not have a water softener yet, do I need one? How quickly will the DI resin deplete?

TIA
Click to expand...
Sounds like it is working to spec.
 
jccaclimber said:
1) If I read that correctly you have carbon after your RO?
2) Bacteria won’t pass through an RO membrane, although dissolved gasses will. Doesn’t mean there aren’t already bacteria there, but I doubt they are going through the RO.

I wonder if you have something living inside the UV unit that gets killed off when you turn it on?
A system diagram would help, I’m a bit confused as to where and why you have a UV unit.
Click to expand...
1) yep. RO --> Carbon-->UV --> out

The system is new, and so is the UV. It's a tankless 500GPD system . The smell and taste only happens if I turn on the UV and system is unused over night. The UV has a flow switch so turns off if not running water through.

Given this, don't think it's the UV housing.

I have a 2 probe TDS meter and it shows slightly elevated TDS from the RO by morning and significantly elevated TDS along with smell from UV end...even if Carbon filter is hypassed.

Short fix might be to swap carbon as last stage after UV to absorb the smell but figured since the unit is tankless, ordering won't have a significant difference

Perhaps it does in my case
 
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