Need some more RODI help please.

Squadir · Sep 22, 2016

Me again guys

So last night I decided to test my unit to make sure everything is ok.
I did a chlorine test on the waste line output (yellow tubing on my unit) and guess what there is some chlorine, its slightly pink but not as pink as the first reading of 0.2 ppm.
When I took a look at the carbon block chamber I noticed that the housing was taking quite a while to fill all the way up, 25 mins and still didn't fill all the way, had about an inch more to go. The last 2 times I made some purified water which is all I ever made (100g), both pre filter chambers just filled straight up.
Is there something wrong or is that normal? Also any ideas why would a carbon block be exhausted after just 100 gallons? To be exact it would be 400 gallons total including waste.

The Rook · Sep 22, 2016

What's your incoming water tds and chlorine?

Squadir · Sep 22, 2016

source water is 260ppm tds
haven't checked the incoming chlorine, will do that tonight when I get home.

The Rook · Sep 22, 2016

The big thing lately is chloramine. If your water dept switched to that it'll eat up the carbon block quickly. There's been alot of discussion lately on the subject.

gtbarsi · Sep 22, 2016

If you are getting lower than normal output and the Carbon chamber seems to be the first to be filling slowly you may need to replace your sediment filter. Do you have a pressure gauge on your RO feed line? If so what is it showing?

Squadir · Sep 22, 2016

gtbarsi said:
If you are getting lower than normal output and the Carbon chamber seems to be the first to be filling slowly you may need to replace your sediment filter. Do you have a pressure gauge on your RO feed line? If so what is it showing?

output is normal, the carbon chamber starts out filling fast till about 1/3 up then slows down. psi on the RO line is the same as when first installed - 65PSI
even if the sediment filter is clogged, it wouldn't affect the chlorine passing through a relatively new carbon block, would it?

gtbarsi · Sep 22, 2016

If your output is normal than it is probably trapped air that is being compressed in the carbon canister.

Regardless the only thing that affects chlorine removal really is the state of the carbon block.
While testing the RO waste line can give you an idea about what is making it through your carbon it is not the best test. The best test is to check the water coming out of the block before it gets to the RO membrane. You have to disconnect the line to do this, some people add a 3 way valve between the two to make gathering a test sample easier.

If chlorine is making it through your carbon block you have a problem. First I would test your water supply to get a reading of the different types of chlorine that are in the water to be filtered. Then I would test the water after it passed through the carbon block. I have never heard of a carbon block failing after a couple of hundred gallons.

I would double check to make sure the carbon block is seating properly, and if you are still seeing chlorine breakthrough I would buy a new carbon block.

What type do you have presently? BRS did a video study of chlorine filtering and a number of different carbon blocks including their new at the time Universal carbon block, which is designed specifically for chlorine, and chloramine.

Happy testing let us know what you find...

AZDesertRat · Sep 22, 2016

What are you testing the chlorine with?
What system do you have and what filters are installed in it?

Squadir · Sep 23, 2016

gtbarsi said:
If your output is normal than it is probably trapped air that is being compressed in the carbon canister.

Regardless the only thing that affects chlorine removal really is the state of the carbon block.
While testing the RO waste line can give you an idea about what is making it through your carbon it is not the best test. The best test is to check the water coming out of the block before it gets to the RO membrane. You have to disconnect the line to do this, some people add a 3 way valve between the two to make gathering a test sample easier.

If chlorine is making it through your carbon block you have a problem. First I would test your water supply to get a reading of the different types of chlorine that are in the water to be filtered. Then I would test the water after it passed through the carbon block. I have never heard of a carbon block failing after a couple of hundred gallons.

I would double check to make sure the carbon block is seating properly, and if you are still seeing chlorine breakthrough I would buy a new carbon block.

What type do you have presently? BRS did a video study of chlorine filtering and a number of different carbon blocks including their new at the time Universal carbon block, which is designed specifically for chlorine, and chloramine.

Happy testing let us know what you find...

I will try testing straight out of the carbon stage before RO and see what I get tonight when I get home. I will also rinse the block in RODI water and reseat to see if it helps. I have a standard 1 micron carbon block from spectrapure.

AZDesertRat said:
What are you testing the chlorine with?
What system do you have and what filters are installed in it?

I'm using the Spectrapure test kit. I have a Spectrapure 90 gpd MPDI 4 stage unit. Standard 1 micron pre filters, 96% rejection membrane ( I get closer to 98% at 95 PSI), and Silica buster color changing DI.

AZDesertRat · Sep 23, 2016

That is strange then, you are using a good carbon block and good test kit and sounds like you have not made much water through it.

Squadir · Sep 23, 2016

It is very strange

not much water made at all and my waste ratio is good, just about 2.8 waste to 1 product. I will take everything apart and rinse with RODI water and re assemble it making sure everything is seated properly when I get home. I have some spare filters so if need be I will change them out and retest.
Is it normal for the second housing (carbon) to take a while to fill when the system is turned on?

gtbarsi · Sep 23, 2016

As you noted the water is moving through at the normal flow and pressure so if you are worried about the air in the carbon housing, slightly loosen it while making water until the air which has likely pressurized can escape, then tighten it back down. Put a bucket underneath it before you try this, to catch any leaks if you are not able to tighten it up before water escapes.