RODI water TDS readings

Gsxkid

Non-member
I had an algae bloom and was thinking possibly my RODI water was causing it. I bought an in-line meter and my TDS readings were 295. I thought the TDS numbers should be lower than that. I just replaced all of my filters in it and my readings are still 225 I’m flushing it out to see if maybe that’s related to water in the lines but what should my numbers be? If they don’t go lower what should my next move be?
 

Gsxkid

Non-member
Thinking maybe I am routing a line wrong I’m hoping . Which tube should be the waste water ? And does the restricter go in the waste line?
 

Gsxkid

Non-member
Thinking maybe I am routing a line wrong I’m hoping . Which tube should be the waste water ? And does the restricter go in the waste line?
 

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gobyvin

Well-Known Member
BRS Member

Waste line.
 

Gsxkid

Non-member

Waste line.


Both are blue on mine any idea which is which?
 

Gsxkid

Non-member
Yeah but which port is supposed to be my waste line?


I pulled the lines off to switch the membrane and the restricter popped out too. I should of taken a picture but I can’t remember what port was waste and what one goes into the DI
 

gobyvin

Well-Known Member
BRS Member
Look at the link that I sent, think it is the second picture maybe third too. Look at the white cartridge that holds the membrane. The JG fitting on the housing where the hose with the flow restrictor is inserted is the one you want to make sure it is installed into. It is the lower, offset or outer fitting.
 

Gsxkid

Non-member
Thank you got it squared away TDS is at 10 and going down looks like I just have to flush it more still going down.
 

this is me

I like turtles
BRS Member
Not necessarily 0-2tds. It’s depend on your source water. A 96-99% rejection rate is a better number. Look up your RO filter manufacturer and see what’s the rejection rate you’re supposed to get.
For comparison, when I was in Pepperell, the source water is around 126ppm. After RO is around 1-2. Now that I’m in Westford, the source water is 246 and I can never get better than 4ppm out of the RO. The RO is doing what Spectrapure says it’s doing. Around 98% rejection rate.

you can easily troubleshoot your RODI filter set up with a handheld tds checker and just drip the line into a cup and measure it.
Source=RO input tds
Waste=higher TDS than RO output
RO output=(100-manufacturer rejection rate)*source water tds
DI input=RO output
DI output=0 on a new DI. 4 tds maybe it’s time to change out the DI
 

MDFiend

Member
BRS Member
I need some help. I'm running a 6 stage RODI, and I am getting 250 tds from my well, and 230 after my NEW sediment filter and 5 micron and 1 micron carbon blocks, and then 25-28 coming out of my dual membranes( one is around 27 and the other is around 20), then I am getting 0 out of my DI, but I'm plowing thru DI resin. I have flushed the membranes for 30 minutes with little change. The unit is a combination of two used four stage units, so I can't tell you how old the membranes are.

I feel like I should be getting a larger drop in tds after the carbon blocks...no?

Anyone have any thoughts?
 

Greg Hiller

BRS Moderator
Staff member
Moderator
BRS Member
You might have high levels of carbon dioxide in your source water. Try taking a TDS measurement before and after bubbling a lot of air through the water. If it drops a lot you may want to consider a method to degas the water before sending into your unit.
 

CrypticLifeStyle

Well-Known Member
BRS Member
I need some help. I'm running a 6 stage RODI, and I am getting 250 tds from my well, and 230 after my NEW sediment filter and 5 micron and 1 micron carbon blocks, and then 25-28 coming out of my dual membranes( one is around 27 and the other is around 20), then I am getting 0 out of my DI, but I'm plowing thru DI resin. I have flushed the membranes for 30 minutes with little change. The unit is a combination of two used four stage units, so I can't tell you how old the membranes are.

I feel like I should be getting a larger drop in tds after the carbon blocks...no?

Anyone have any thoughts?

Well life, do you know when the last time your bladder tank was replaced?
 
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