RO for drinking plumbing question

[skr791346]

Setting up a spare RO unit for drinking water but confused on connecting the chlorine remover filter, do I have it set up right?

 

[rusty hannon]

I'm sorry I really don't know lm follow ing you for your knowledge or lesson here.im learning on the fly .if I can I'll look on this computer n c what it says but l myself don't know.

 

[amps]

No. The Chlorine filter goes before the membrane.

 

[skr791346]

Are you sure? Looking at BRS picture here

 

[skr791346]

Confirmed that most people put the omnipure carbon block (chlorine taste reduction) after the membrane...

But tds measuring out of membrane is 3ppm and tds measuring after omnipure carbon block (final product water) goes back up to 9ppm, is this normal?

 

[amps]

But you'll notice that all of BRS' units have another carbon block before the membrane. That's because chlorine and chloramines will damage RO membranes and punch little holes in it, reducing it's effectiveness. The block added at the end is to polish any small remnants that squeak through, not to do the bulk chlorine removal.

 

[skr791346]

But you'll notice that all of BRS' units have another carbon block before the membrane. That's because chlorine and chloramines will damage RO membranes and punch little holes in it, reducing it's effectiveness. The block added at the end is to polish any small remnants that squeak through, not to do the bulk chlorine removal.

My unit has a carbon block before membrane as well, unless I'm misunderstanding you? It goes from sediment > chlorine carbon block > universal carbon block > membrane > omnipure inline carbon block

 

[amps]

You've got it right then. It didn't look like there was any prefilters in your picture.

I wonder if the TDS creep going up is caused by small bits of the carbon finding their way into the product water?

 

[skr791346]

That’s what I was thinking too. Odd thing is, when the water is “full”, In tds shows 55 after membrane and Out tds shows 23 after final carbon but as soon as I drain the stores water and there’s active pressure, it flips and lowers to 3 In & 9 out

 

[amps]

That's because when the shutoff valve is closed, the high TDS water on the waste side creeps it's way through the membrane into the product side, causing elevated TDS until it gets flushed out again. It's potentially a factor to high nutrients or algae issue in reef tanks that have an RO line plumbed permanently rather than using a reservoir.

 

[skr791346]

Ahh makes sense. Would putting a check valve on the waste line resolve this?

 

[amps]

Unfortunately not. It's the water that's on the input/waste side of the membrane in the actual canister that's slowly filtering through when the unit isn't flowing.

It's called 'TDS Creep'. BRS actually just a good video on this subject, worth checking out: