RODI...ugh!

[Ratbrow]

So, apparently I have been reading my TDS meter wrong for the last 2 months. Anyway, it turns out that my RODI unit (Baracuda 3 stag) has been giving me water at 10PPM this whole time. Any ideas why a brand new RODI unit wouldn't be cleaning my water to 0?

This may explain why I have been dealing with Green film algae for the last two weeks. I don't know, is 10ppm bad?

I tested my water before it went into the unit and it was 220ppm. I love this hobby, but some days I feel like throwing a guppy in a fishbowl and calling it a day. It sucks being a noob. I guess we all need to learn.

 

[nlgill13]

yea...you want 0 ppm TDS. Sounds like you might want to flush the membrane

 

[Reefmedic79]

Are you sure it's a 3 stage?

3 stage tells me that it isn't an RO/DI unit, but only an RO unit.

Stage 1 particulate filter
Stage 2 carbon filter
Stage 3 RO membrane
Stage 4 DI media

If it is in fact only a 3 stage then 10ppm TDS is exactly where your water should be at, and you will need a DI cartridge to bring the TDS to 0ppm

 

[snorvich]

Are you sure it's a 3 stage?

3 stage tells me that it isn't an RO/DI unit, but only an RO unit.

Stage 1 particulate filter
Stage 2 carbon filter
Stage 3 RO membrane
Stage 4 DI media

If it is in fact only a 3 stage then 10ppm TDS is exactly where your water should be at, and you will need a DI cartridge to bring the TDS to 0ppm

Exactly.

 

[EricBuzz]

Post a picture of the unit. How old is the membrane?

 

[dkeller_nc]

After looking at AquaFX "barracuda" units on Drs. Foster and Smith, it appears that you actually do have a 4-stage unit. A "four stage" unit, by the way, will actually have 3 screw-on filter housings with cartridges in them; the RO membrane & housing counts as a "stage".

There are multiple reasons why you might not be getting 0 TDS water out of this unit. Here are some:

1) The RO membrane seals are displaced/damaged inside the housing - this will allow tap water to bypass the RO membrane, and quickly saturate your DI stage.

2) The seals on your DI stage are displaced/damaged.

3) Your TDS meter is out of calibration and/or not being used properly. For example, putting 0 TDS water into a glass container and using a "pen-type" TDS meter is highly unlikely to give you a 0 TDS reading.

4) Your carbon filter block is exhausted and not removing all of the chlorine/chloramine in your tap water, which can damage your RO membrane, lower its selectivity (leading to higher output TDS), and rapidly saturate your DI stage.

5) Your water source contains a great deal of dissolved CO2, which can quickly saturate your DI resin.

 

[Ratbrow]

After looking at AquaFX "barracuda" units on Drs. Foster and Smith, it appears that you actually do have a 4-stage unit. A "four stage" unit, by the way, will actually have 3 screw-on filter housings with cartridges in them; the RO membrane & housing counts as a "stage".

There are multiple reasons why you might not be getting 0 TDS water out of this unit. Here are some:

1) The RO membrane seals are displaced/damaged inside the housing - this will allow tap water to bypass the RO membrane, and quickly saturate your DI stage.

2) The seals on your DI stage are displaced/damaged.

3) Your TDS meter is out of calibration and/or not being used properly. For example, putting 0 TDS water into a glass container and using a "pen-type" TDS meter is highly unlikely to give you a 0 TDS reading.

4) Your carbon filter block is exhausted and not removing all of the chlorine/chloramine in your tap water, which can damage your RO membrane, lower its selectivity (leading to higher output TDS), and rapidly saturate your DI stage.

5) Your water source contains a great deal of dissolved CO2, which can quickly saturate your DI resin.

Sorry, you are correct...it's a 4 stage.
So what do you suggest I do? Maybe I should call the manufacturer and see what they say. The unit is only 2.5 months old, just like my tank.

 

[M Reed]

flush. if that doesn't work contact the manufacturer

 

[Every1jockzjay]

Is it a dual tds meter???? U maybe reading before it goes to di stage...also running hot water can also ruin ur membrane

 

[Every1jockzjay]

Nvm it doesnt have a dual tds meter guess ur using handheld...but if your using hot water the membrane could b shot, or even if its not messed up ywt using hot water can swell the membrane allowing particles to pass through, if ur using hot try cold and test it

 

[dkeller_nc]

Sorry, you are correct...it's a 4 stage.
So what do you suggest I do? Maybe I should call the manufacturer and see what they say. The unit is only 2.5 months old, just like my tank.

Well, one tip is that you want to measure TDS after the unit has been operating for at least 10 minutes. When an RO/DI system is stagnant, an equilibration of the ionic content of the water throughout the system occurs; in other words, the output of the unit is only "pure" after it's been running for a while and the RO & DI housings have been flushed.

From the standpoint of the carbon filtration exhaustion, I replace both a BRS loose-carbon stage and a pentex chlor-plus carbon black every 3 months. In may case, that works out to replacement every 2000 - 3000 gallons of total throughput (that figure counts both the product water and the waste water).