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Filtering Chloramine from Compost Tea

By on July 09, 2009

PVFS Customer Email with Staff Response


I am an avid home brewer of compost tea.  I use to rid my water of chlorine by running the pump 1 hour prior to brewing.  However, I have now moved to an area that has chloramine treated water.  It is my understanding that chloramine cannot be removed using the same process as the chlorine.  Will the subject Gard ‘N Gro Garden Filter remove chloramine to the extent that it will not kill off the microbial activity in the “soil soup” or compost tea?

Thanks for your help!  I need to find an answer as I don’t want to have to buy bottled water to make the tea!


I spoke to the manufacturer of the Gard ‘N Gro Dechlorinating Filter about your question.  Although that filter does remove some of the chloramine (maybe about a 25-30% reduction), to remove more requires slower flow rates and more of the media in the filter.  They make a product called the Green Knight Hydroponic Dechlorinator made for your type of situation.  It is designed to reduce the chlorine and chloramine in tap water when filling hydroponic nutrient tanks.  It removes 85-90% of the chlorine and reduces chloramine over 60%.  It uses a much slower flow rate and has twice as much filtering media and surface area than the Gard ‘N Gro Dechlorinating Filter.  It does not use replaceable cartridges, but has a 30,000 gallon capacity.  It reduces more chloramine if the water pH is in the low sevens or lower and the warmer the water, the more effective it is.  We haven’t offered the Green Knight in our catalog, although we may in next year’s catalog.  We can get one in with our next order, if you want to order one.  They are approximately $10 more than the Gard ‘N Gro Dechlorinating Filter.  We will be placing an order with the manufacturer within the next week or so.  Let me know if you want to order one.

Thank you for growing organically!

This correspondence Continued:

Reply from Customer:

Wow!  Thanks for all the research!

I do think I may want to order the Green Knight Hydroponic Dechlorinator.  However, before I do I need to know more.  Does this filter hook up “in-line” between your faucet and a hose, or is it bigger than that requiring some sort of installation?  And I still don’t know if the 60% reduction is good enough for brewing compost tea.  Do you have a sense of that since you are offering compost tea brewers now?  Is this something that you would recommend to customers buying your compost tea brewers and supplies?

Many, many thanks.  This issue with chloramines in the water and compost tea is a tricky one.  A google search on the internet indicates that there are a LOT of people looking for answers but there aren’t any out there really.  Humic acid and fish aquarium neutralizers are the only suggestions.  The fish aquarium neutralizers are all sodium based…..not good for the soil!  All this is food for thought for a New Product Development Manager…..........

Response From our Staff:

The Green Knight comes with the same 3 foot vinyl reinforced hose saver that comes with the Gard ‘N Gro Dechlorinating Filter.  It attaches to the hose bib and then to the filter.  The Green Knight also comes with a built in pre-filter for particulate matter, so you don’t have to buy a separate pre-filter.  I am trying to find out from some compost tea experts if 60-70% reduction in chloramines is adequate.  If I get more info, I’ll let you know.  I’m also not sure if the amount of sodium in the aquarium neutralizers is significant enough to be a detriment to the soil or the compost tea itself.  I am not familiar with what is in them or what chemical reaction occurs when it eliminates the chloramine.  If you know, please let me know.

  Comments (7)


The chlorine/ chloramine discussion has piqued my interest.  Sometimes when I’m feeling ambitious I’ll use ‘pond’ water to irrigate my garden.  It’s a black plastic pond shell not earthen and the water is pumped up through tubing and splashes back down.  I figure that the aeration dissipates most of the chlorine over time.  I’m wondering if chloramines in the water would also be dissipated.  And (as I’m reading my city’s annual water report) I’m wondering about bromate haloacetic acids trihalomethanes—-all of them disinfection residuals/ byproducts.  Anyone want to take a crack at these?



Posted by david allen on Jul. 13, 2009 at 7:55:54 PM


Chloramine doesn’t produce the same by-products as chlorine does and that is one reason some municipalities are switching to it. Neutralizing can be done according to the following (as I have read from reputable sources however I myself am not an expert of course- I mean reputable and internet ... an oxymoron right?)
1) chloraminated water that is left to sit out over several days will mostly be neutralized. this is compared to the shorter time period of letting chlorinated water sit out.
2) carbon filters
3) adding vitamin C to the water - 1 gram is enough to neutralize a bathtub’s worth of chloraminated water
4) gently boiling water for 20 minutes. obviously highly inefficient since much of your water boils away and you’re left with hot water

what i read is that through the preparation of most foods the chloramines are neutralized. so your tea coffee soups etc are actually chloramine free.

Check here:

Posted by jason hiller on Jan. 24, 2011 at 5:31:19 PM


I have been “brewing compost tea for a year now.
1. In my experience, If you leave the water witht the pump and aeration on for 72 hour at least it seems to neturalize the chloramine.
2. I dunno if it is feasable but you may think about setting up a rain barrel or rain catch system.
3. ^^ Jason Hiller has the rest lol

Posted by Jason L. on May. 03, 2012 at 9:33:00 PM


Chlorine and Chloramine are a pain to brewing beer as well. To get rid of either or both in about 1-2 minutes, home brewers use Potassium Metabisulphite or Sodium Metabisulphite, commonly called Campden tablets. They are available from homebrewing or home winemaking stores and usually cost less than 5 cents each.

Use one tablet, prior to making the compost tea, to 100% eliminate chlorine / chloramine from 20 gallons of water. It works by converting the Chlorine or Chloramine to calcium chloride and calcium sulfate (gypsum), both naturally occurring compounds and beneficial for plants.

Posted by Mark Foster on Aug. 05, 2012 at 7:06:31 AM


Make a liquid humic acid solution by filtering water through some compost. It is great for neutralizing both chlorine and chloramine in compost tea’s water.

Just slowly add drops of your liquid humic acid solution till the water just starts to show a color change. The chlorine or chloramine will have been neutralized.

Posted by John Bridges on Mar. 02, 2013 at 1:36:56 PM

Thanks to you all for your helpful information!

Posted by on Mar. 02, 2013 at 7:52:27 PM


I called my local brewshop.  He insisted that the campden tablets work fine for chlorine but won’t for chloramine.  Chloramine is too stable for sulfite products like campden.

He suggested there is more hype around chloramine because it’s usually not strong enough in municipal water supplies.

Posted by Micky Lee on Jan. 08, 2015 at 3:28:49 PM

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