Which chlorine/chloramine RO/DI should I buy?

[Miami Reef]

Can someone suggest the proper chlorine/chloramine filter for my RO/DI unit?

I use a 1 micron sediment filter, and I have 2 carbon stage filters.

I live in Miami. I recently purchased a total chlorine test kit, which also tests free chlorine

I usually change the closest carbon block at the same time my sediment filter gets exhausted, then I switch the older carbon block, and put it next to the sediment filter, then put the new carbon block in the 2nd carbon spot.

I’m looking on Amazon, and I see all sorts of carbon types, some better for chloramines, while others look suited for drinking water.

How can I know if I have chloramines? How will I know when to change my carbon blocks? Do I have to change them both at the same time?

 

[jsker]

I was always under the impression that between the carbon and DI, that would filter out the chlorine/chloramine.

It will be interesting to see the responses.

 

[Randy Holmes-Farley]

How can I know if I have chloramines? How will I know when to change my carbon blocks? Do I have to change them both at the same time?

Does you water supply company say it uses chloramine?

Any chlorine kit will detect chloramine too.

I personally would not spend extra money on special blocks without some indication that a normal carbon block was inadequate (detecting chlorine or chloramine in the final effluent). In my tests on my tap water with chloramine, and those of members I sent a chloramine kit around to, a normal block was adequate.

 

[piranhaman00]

You want HACH chlorine test strips.

Chloramine is Total chlorine minus free chlorine.

Test your RO waste water line to see when carbon blocks are exhausted. If chlorine is in your waste you have chlorine getting past carbon blocks.

Chlorine destroys RO membranes and chloramine is not readily grabbed by DI.

 

[Sisterlimonpot]

Typical carbon blocks have a hard time removing chloramine from water. That's why it's recommended to purchase carbon blocks that are rated for chloramine. I'm not 100% sure what the differences are between the 2, whether it's the micron filtration or the actual gac.

unless you know for sure what your water treatment plant uses it's a crap shoot. There are ways to test your waste water from the membrane to see if there's any total chloramine. If you have new carbon blocks and total chlorine is detected then there's a good chance they use chloramine.

Bottom line, if you know there's chloramine in your water, you'll want to get carbon blocks specifically for chloramine.

 

[Randy Holmes-Farley]

Typical carbon blocks have a hard time removing chloramine from water.

Do they? Have you seen this yourself, or just read it from a reseller of special blocks?

Chloramine and the Reef Aquarium - Reefkeeping.com

Consequently, within the capabilities of the Hach test kit (0.01 ppm), there is no chloramine getting through the system. A small amount does appear to get past the carbon to the RO waste water, but it does not get through the RO membrane and DI resin.

A similar set of data (more or less complete) was collected from about 20 aquarists in different parts of the country. These included systems that were stated to have a capacity of 25-100 gallons per day, the higher volume systems being especially interesting because the contact time with the carbon might be shorter. All but one had similar results to those reported here.

 

[rtparty]

BRS has a great video or two on this.

Any block labeled for chloramine is just marketing. The key is using 2 carbon blocks and replacing them more often than normal if your city uses chloramines instead of chlorine.

The BRS carbon blocks are noticeably better. I wish I had the picture comparing theirs to others. It might be on their site even.

 

[KStatefan]

From the specs I have seen chlorimine capacity is about 10% of the chlorine capacity at half the flow rate.

ie specs from a Filtrex filter.

 

[Sisterlimonpot]

When I was stationed in California I ran an an rodi with dual carbon block. The tap water did have chloramine and I was getting total chlorine post carbon block. I used those exact test strips that Miami posted. I remember, I purchased them from the pool supply store.

I don't remember what "chloramine" carbon blocks I ended up with but they removed total chlorine.

Could this have been a case of coming to the wrong conclusion based on my experience? Absolutely. It wasnt until this very moment when my experience was challenged, to question its validity. (It's been close to 10 years now since I left California)

So, it seems that dual carbon filters provide longer contact time and perhaps carbon blocks that are specific to chloramine have more gac??

 

[SteveMM62Reef]

For our Flake Ice Machines we used these; Aquaticlife Carbon Plus Carbon Block Water Filter. We put a Cheap Sediment Filter, before it to extend the life of the Cloramide Filter. Be aware they can start dumping Chlorine if they get overloaded. They start to seep Chlorine at first. BTW We got one too two weeks out of them on high usage Dispensers, in a Food Service Setting.

​

 

[EeyoreIsMySpiritAnimal]

Chloramine is Total chlorine minus free chlorine.

No, chloramine is chlorine plus ammonia.

 

[Miami Reef]

edit. I’m going to call my water supply.

 

[Randy Holmes-Farley]

No, chloramine is chlorine plus ammonia.

He means in terms of testing, how you get a chloramine number, rather than what it is made of.

 

[EeyoreIsMySpiritAnimal]

He means in terms of testing, how you get a chloramine number, rather than what it is made of.

Oops!
Thank you!

 

[KStatefan]

edit. I’m going to call my water supply.

I think it is good to assume you have chlorimines because the water plant can start using them at anytime with no notice.

 

[Miami Reef]

I think it is good to assume you have chlorimines because the water plant can start using them at anytime with no notice.

a quick google search says yes, I do have them.

 

[Randy Holmes-Farley]

a quick google search says yes, I do have them.

Do you have those test strips now?

 

[Miami Reef]

Is the test kit I got even accurate enough for the levels I’m trying to detect?

How low should total chlorine be? I think I’ll just get the chloramine filters and change them when the test shows mildly detectable?

 

[Miami Reef]

Do you have those test strips now?

I do.

 

[Randy Holmes-Farley]

I'd try them on tap water, RO/DI waste water (= water in front of the RO membrane) and on the RO/DI final effluent.

Let the RO/DI run for a bit so you are checking representative water, since water sitting in or near the carbon block when it is off gets a much longer exposure.