another R/O problem

[sick1166]

I have a new 200gpd brs ro unit the tds going in is 127 and coming out is 23 re checked membrane seating all is good. Well I bought 2 new membrane and installed them and getting the same readings
124 going in 22 coming out?
I am on well water 77 water temp 6.2 ph 3 grains of hardness no iorn or anything else the company's that have tested my water say this is like great water .
So what am I missing

 

[Robert_ellis]

How long are you running the membrane before the 23 reading?

 

[stacksoner]

How quickly does your sediment filter expire?

I'm taking a new, more controlled approach to RODI that I borrowed from the wood sanding world. , I In short, Im starting w a 5 micron sediment filter, 1 micron sediment filter, .5 micron sediment filter, .2 micron carbon block, RO membranes, DI finishing canisters.

I believe that gradually filtering water that will go into my RO filters will produce better quality water, increase filter efficiency, and decrease chances of overtaxing a filter, which I believe is the cause of many RODI purity failures

 

[sick1166]

I ran for 1 hour but the 23 was right off the bat i have 2 tds testers get tha same reading with both

 

[stacksoner]

What's your TDS before water enters the first stage of filtration (TDS of the water from your well).

 

[sick1166]

From the well tap is 126 and the same right before the membrane 126 coming out of ro is 23 and di is o but eats di like crazy

 

[KorD]

Well water is a lot different then tap water on being more harsh for RODI systems in general. Do you run the water through a softener or purification system first?

 

[EmdeReef]

From the well tap is 126 and the same right before the membrane 126 coming out of ro is 23 and di is o but eats di like crazy

What’s the water pressure? if Outside the rated range that could be the cause.

Consider a spectrapure membrane much better rejection rates than most.

 

[stacksoner]

To add on to what @EmdeReef suggested, email Spectrapure and ask for their filter suggestions for your zip code and water source type.

BRS doesn't address the fact that there are different filter combinations that work perfectly for the various water sources out there---and that the filters they sell may not be correct for any given setup.

I used to burn through all prefilters and multiple stages of DI resin after 75 gallons, which killed my tank bc of silicate contamination. Not an issue anymore!

 

[Mjrenz]

Are you using a booster pump?

 

[Opus]

Do you need a 200 gal unit? A 1 membrane unit is much easier on the DI usage.

To see if the membranes are the issue, we need readings after each one to calc the efficiency. Get the tds of the good and waste water after the first membrane and the good water after the second membrane. I'm not sure if your 22 tds number is a combination number of the 2 membranes or just the second membrane.

Also, where do you have your booster pump hooked up.

 

[stacksoner]

From the well tap is 126 and the same right before the membrane 126 coming out of ro is 23 and di is o but eats di like crazy

Can you take a picture of the pre-membrane filters? The purpose of each filter stage is to remove TDS from the water. But yours don't seem to be filtering anything.

 

[Robert_ellis]

Can you take a picture of the pre-membrane filters? The purpose of each filter stage is to remove TDS from the water. But yours don't seem to be filtering anything.

Was thinking the same thing. Odd his prefilters do nothing. Sounds like it may be hooked up wrong.

 

[Opus]

Can you take a picture of the pre-membrane filters? The purpose of each filter stage is to remove TDS from the water. But yours don't seem to be filtering anything.

Pre-filters have no affect on TDS. Their micron rating is too high. Their only job is to protect the RO membrane. The sediment filter is there to take out the larger particles in the water and to keep the carbon filter from becoming clogged up too quickly. The carbon filters job is to take out the chemicals that would harm the RO membrane.

 

[Robert_ellis]

I would have to disagree as I have 4 tds meters on my ro and each stage is lower than the previous stage

 

[JoshH]

Pre-filters have no affect on TDS. Their micron rating is too high. Their only job is to protect the RO membrane. The sediment filter is there to take out the larger particles in the water and to keep the carbon filter from becoming clogged up too quickly. The carbon filters job is to take out the chemicals that would harm the RO membrane.

+1 On this, Prefilters can remove *some* things that might be reading as TDS but this is not there primary function and it's entirely possible that fully functioning prefilters will not provide any reduction in TDS depending on what's in the water that's being run through them. This is one of those things like many other things relating to RODI setups that varies greatly from user to user depending on there water source and setup.

 

[sick1166]

Going thru a 5 micron than a 1 micron and the 2 membranes and a cation anion and than a mixed bed
I will switch to 1 membrane and get tds after each one thanks for that idea