Chloramines

[Treefer32]

I've recently bought a bottle of Seachem chlorine remover / treatment. It says it also removes Chloramines. Which got me thinking. I know that chloramines can make it through RO systems maybe even through DI Reson (not sure).

I run 1 sediment filter and two carbon filters on my RO unit plus two RO membranes and DI resin. My biggest question are what are the side effects of Chloramines on a reef? If I were to just inspect the tank for signs of it what would the signs be? I know they're "bad", but what would the impact be?

I was wondering if I should be treating all my fresh RODI water and waterchange salt water with the chlorine / chloramine remover. It says that it removes it as ammonia on the bottle.

But it got me thinking what if chloramines are making it into the display what would I look for? Are there visible signs?

 

[jccaclimber]

Let’s go stage by stage.
1. Chloramines will always pass through the sediment filter, nothing to stop them there.
2. The carbon block(s) should stop all chloramines. Detectable chlorine (and I suspect ammonia, but someone else can chime in on that) past the carbon blocks are a sign that they need to be replaced.
3. Both ammonia and chlorine are dissolved gasses, so they can pass through the RO membrane just like dissolved CO2. It won’t do your membranes any favors on a long term basis.
4. Your DI resin should catch any chloramine or it’s byproducts that make it that far, but I suspect carbon blocks are a cheaper way to extract it than DI resin.
5. If it’s showing up in your product water your DI isn’t doing it’s job. You can use something like Prime to neutralize it, although I’m not sure how long that applies for, I should start a thread and ask Randy about that. I’d bet you will still end up with very mild nitrogen source from the ammonia.

Back when I used a ton to RO water, but didn’t use DI (needed a couple hundred gallons of soft water for a fresh water tank per week) I figured out it was cheaper to trash an occasional RO membrane and put Seachem Safe in my product water than it was to constantly change carbon blocks. This math greatly changes however when you want 0 TDS water and are using DI resin. Carbon blocks have also gotten better in the decade since then.

Side note, I’m proud I’m of my phone’s autocorrect. I grossly misspelled a word writing this post and it guessed ATO, even capitalized (I didn’t tell it to) as the autocorrect option. Not the right word, but a good guess.

 

[jccaclimber]

Found my own answer. I won’t link to the source as it’s a page selling the product, but here is the quote:
“ Q: How long does Prime stay bound to the ammonia, nitrite, and nitrates?
A: Prime will bind up those compounds for up to 48 hours. If they are still present after that time frame, they are released back into the water, unless Prime is re-dosed accordingly. Also, if your ammonia or nitrite levels are increasing within a 24-hour period, Prime can be re-dosed every 24 hours.”

Following this, if you’re using it to take care of chloramine or ammonia in your product water, add it when you use the water, not well in advance.

 

[Treefer32]

Then, I probably don't have it in the display. I was curious because I hadn't been on top of my DI Resin. TDS had crept up to 11 with my last making of 75 gallons. I replaced the DI and input TDS was 9 and output was 0 again.

I also was wondering the "side effects" of Chloramine. Would it cause algae outbreaks, diseases in fish, or something else? Just curious if it made it into the tank what would happen?

 

[Rybren]

If you have any TDS after your DI stage, then it could be releasing ammonia into your product water.

 

[Randy Holmes-Farley]

The easy way to check Ro/di water for chloramine is with any cheapo chlorine kit. Don’t be fooled into buying special equipment unless you find you need to. Most people using a quality ro/di will not detect chloramine.
Be careful to not let the di deplete because the ammonia released when that happens can be much higher than from the starting water alone.

 

[Dkeller_nc]

3. Both ammonia and chlorine are dissolved gasses, so they can pass through the RO membrane just like dissolved CO2. It won’t do your membranes any favors on a long term basis.

Technically, ammonia and chlorine in the form of chloramine aren't dissolved gases. And while it is true that a solution containing the ammonium ion will off-gas ammonia, the actual dissolved form isn't quite a gas either. The same is true for chlorine.

Instead, the reason that these will pass through an RO membrane is a bit more complex. Specifically, the RO membranes that we use are highly selective with respect to charged, ionic solutes such as potassium, sodium, chlorides and the like. They are also highly selective with respect to larger molecules such as proteins. They are not so good at rejecting small neutral molecules, and in the case of ammonia in particular, the molecule exists as an equilibrium between a charged ammonium ion (NH4+) and a neutral ammonia species (NH3). The neutral ammonia species will pass through an RO membrane much more readily than something like sodium, potassium, magnesium, etc....

 

[Treefer32]

Interesting. So, chloramine equals Chlorine+ Ammonia. So, if chlorine remained bacteria populations would be dying off and Ammonia would be polluting the water killing the livestock. Given that fish and corals appear healthy so far. I do not think there's ammonia.

 

[Dkeller_nc]

Interesting. So, chloramine equals Chlorine+ Ammonia. So, if chlorine remained bacteria populations would be dying off and Ammonia would be polluting the water killing the livestock. Given that fish and corals appear healthy so far. I do not think there's ammonia.

From the standpoint of the effect on the tank, it would strongly depend on the amount of evaporation make-up and/or water change %. For municipal water, the max concentration of chloramine that's allowed is 4 ppm. That works out to 0.078 millimole/L of chloramine. Since there's one mole of ammonia per mole of chloramine, that works out to 1.3 ppm of ammonia if all of the chloramine was converted to chlorine and ammonia.

While no one would want to expose their animals to 1.3 ppm of ammonia, that's the max that could be in untreated municipal drinking water. So presuming that your top-off was at most 3% per day, you'd only be adding 0.04 ppm of ammonia per day. Any cycled tank would very rapidly reduce that to near zero. And that's if your RODI system was totally non-functional and your municipality was using the maximum chloramine concentration.

 

[jccaclimber]

I didn’t know our membrane efficiency is impacted by charge In addition to size, interesting.
On the topic of chlorine, what is the concentration/time at which we would expect it to harm the bacterial population in our systems? I’m not planning on using untreated tap at top off any time soon, but I am curious as to where the limits are.

 

[Randy Holmes-Farley]

Interesting. So, chloramine equals Chlorine+ Ammonia. So, if chlorine remained bacteria populations would be dying off and Ammonia would be polluting the water killing the livestock. Given that fish and corals appear healthy so far. I do not think there's ammonia.

No. It is different than either chlorine or ammonia.

 

[Randy Holmes-Farley]

I didn’t know our membrane efficiency is impacted by charge In addition to size, interesting.
On the topic of chlorine, what is the concentration/time at which we would expect it to harm the bacterial population in our systems? I’m not planning on using untreated tap at top off any time soon, but I am curious as to where the limits are.

Thats complex, but it is not charge directly. It is still size, but charged ions attract from one to a dozen tightly bound water molecules, and that makes them effectively much larger than an uncharged molecule like chloramine, methanol, water, or similar small neutral molecules.

 

[Randy Holmes-Farley]

I’ve not seen any data in which organisms in our aquaria are most sensitive to chlorine or chloramine, or what the safe limit is, but I would not assume it is necessarily bacteria.

 

[tvan]

Or you could let your water sit out 24-48 hours. Chlorine off-gases. Or in the case of chloramine you can hyper-chlorinate then let the chlorine off-gas. I believe the bio-load in most tanks would overwhelm the small amounts of chlorine in tap water.

 

[jccaclimber]

What is the mechanism by which carbon blocks treat the chloramine? Do the absorb it directly, or break it down and absorb those byproducts? Is there a partially functional stage where part but not all of this process occurs, or does the % of treated/bound molecules simply decrease as the carbon block fills?

 

[Randy Holmes-Farley]

What is the mechanism by which carbon blocks treat the chloramine? Do the absorb it directly, or break it down and absorb those byproducts? Is there a partially functional stage where part but not all of this process occurs, or does the % of treated/bound molecules simply decrease as the carbon block fills?

Carbon catalytically breaks chloramine down into chloride and ammonia. It does not fill up, but can get clogged with sediment and other things.

I discuss the details here;

http://reefkeeping.com/issues/2003-11/rhf/feature/index.htm