RODI Issue - What am I missing?

[leewish]

Hi,

I have a 7 stage Spectrapure RODI unit....1 pre filter (1 micron), 2 Carbon filters (1 micron each), 2 100gpd membranes and 2 DI mixed bed color changing resins. Media for these are BRS media (Filters, Carbon blocks & DI).

Recently my unit has been burning up DI. I went through 1/2 a cartridge filling a 32g brute.

I swapped out everything and it still did it. So I bought new membranes (were originally replaced in September 2024 (so little over year old) and still burned 1/2 a cartridge of DI resin.

I also have a whole house sediment filter at 30 microns filtering particulates before it even hits the RODI unit.

What am I missing to try next?

 

[Matt L]

Are you on a well?

 

[KrisReef]

Water pressure too low? Otherwise???

 

[leewish]

Are you on a well?

Public Water....no well

 

[leewish]

Water pressure too low? Otherwise???

Pressure gauge shows 60 when making water.

 

[Matt L]

With two 100 gpd membranes, you may need a booster pump to get the pressure up to around 75-80 psi.

 

[leewish]

With two 100 gpd membranes, you may need a booster pump to get the pressure up to around 75-80 psi.

For years I've been making it with them at 60psi. Its a 180GPD unit so they are slightly off at 100 each....but trying to figure out why its all of a sudden

 

[Largeangels]

What is the TDS of the water going into the RODI?

 

[emvanburen]

and are you making large batches or doing small refills with more on/off cycles

 

[leewish]

What is the TDS of the water going into the RODI?

170ish

 

[leewish]

and are you making large batches or doing small refills with more on/off cycles

big batches. do not have it automated (no solenoids). Flush the membranes for a minute before starting.

 

[Kooma]

What is your TDS out of your membrane? Is it possible you have your waste line going to the DI resin?

I was cooking through DI on an inner unit and after moving my tds to the output of my membrane found it was 32 tds into my DI. I swapped membrane and get 1tds to the DI, filled a 270gallon system and used half a DI resin.

Check your plumbing.

 

[Kooma]

What is the TDS of the water going into the RODI?

170ish

There’s the issue. This should be 1.

You likely have your waste line going to the DI. Check the tds on your waste water. I bet it’s under 5.

 

[leewish]

There’s the issue. This should be 1.

You likely have your waste line going to the DI. Check the tds on your waste water. I bet it’s under 5.

When you say going into my RODI I assume you mean coming in from the tap going into the unit...thats why I said 170ish. I will check all the plumbing again. Maybe make a video tonight.

 

[leewish]

There’s the issue. This should be 1.

You likely have your waste line going to the DI. Check the tds on your waste water. I bet it’s under 5.

Will check the plumbing tonight and make a video.

 

[KStatefan]

Public Water....no well

Lots of public water supplies come from wells

 

[leewish]

Lots of public water supplies come from wells

Been in same house for 15 years....definitely on town public water not a well. Get a report each year from the township for testing.

 

[KStatefan]

Been in same house for 15 years....definitely on town public water not a well. Get a report each year from the township for testing.

OK
Was just pointing out that being on public water does not mean it does not come from a well. Very common where I am from. Think it is about 1/3 in the USA.

 

[Naekuh]

If your burning DI, it means water going from your RO -> DI must be bad.

What is the TDS right b4 the DI? Your water IN doesn't matter, its Water OUT from RO -> DI what's important.

If that is good, then i want to say you probably sourced bad Resin, or old resin.
Not all resin is the same...

 

[JTP424]

Might be worth getting an inline tds, then you can also confirm when certain membranes are going bad.