Rodi problem

[Reef craze]

Okay so my friend has a 6 stage rodi unit and he is eating up di resin like crazy. Took him forever to make 30 gallons like 2 days and used a half canister of di for 30 gallons any idea what the issue is.

 

[Spieg]

Sounds like may be low water pressure. What order does the water pass from canister to canister?

 

[Reef craze]

Sounds like low water pressure.

Would that deplete the di resin by half for 30 gallons

 

[Reef craze]

Sounds like low water pressure.

This is an old picture at like 3 gallons

 

[Spieg]

If it took 3 days, then the membrane is not going to work very efficiently.

 

[Reef craze]

If it took 3 days, then the membrane is not going to work very efficiently.

That’s what made me think it was hooked up wrong. I live in wv he lives in New Mexico so I’m trying to fix it over FaceTime

 

[Spieg]

Should go thru the
1) sediment filter
2) carbon block 1
3) carbon block 2
4) RO membrane
5) DI resin 1
6) DI resin 2

Looking at the photo I can't tell how it is connected but it almost looks like the resin may be first? I always try to plumb stuff from left to right.

 

[Shirak]

Any idea what the pressure is at the source? Is your friend on a well?

 

[Cory]

High dissolved Co2 will waste deion resin very quickly

 

[homer1475]

Any idea what the pressure is at the source? Is your friend on a well?

High dissolved Co2 will waste deion resin very quickly

Was going to suggest this myself. Typically well water is high in Co2 which will kill DI resin very quickly.

 

[Spieg]

CO2 or well water still doesn't explain the 10 gallons per day output on a new system... there's something else going on here.

 

[Reef craze]

Any idea what the pressure is at the source? Is your friend on a well?

Yes on a well 65 psi coming into unit

 

[homer1475]

Not that it matters, but why does he have a second sediment cartridge before the RO?

To me it looks like sediment, carbon, sediment, RO, and 2 DI.

I personally would check the pressure after each stage, but just guessing is something is either blocking the water flow, or one of the cartridges is full of gunk.

If he removes all the cartridges(even the RO), does the pressure drop?

 

[KStatefan]

Yes on a well 65 psi coming into unit

What is the pressure at the membrane?

Has your friend changed the membrane to something different then the system came with and not matched the flow restrictor to the new membrane size?

Prior to adding a degassing chamber to my system my max cap di only lasted for 50 gallons.

 

[Shirak]

CO2 or well water still doesn't explain the 10 gallons per day output on a new system... there's something else going on here.

Yes there is something else going on. The well water can explain the DI resin if it's CO2. Well water is often very cold too. So even at 65psi, ground water at 55 degrees f. can have a big impact on RO production.

I would test the pressure after the prefilters to make sure they are not clogged and dropping the pressure. I would also be curious as to the water temperature going into the unit. Most RO membrane production rates are for source water around 78 degrees.

I am also curious as to the 3rd prefilter. Is it another sediment filter? Could be a very fine 1 or .5 micron that is cutting the pressure.

Booster pump would help with the production if there is a pressure issue and/or cold source water.