Spliffy Twojoints
Active Member
I recently read a very interesting article about chlorine and chloramine levels in drinking water, relative to average houseplants. I will attach a link at the bottom of this post for anyone interested in reading it in detail.
To summarize, the levels of chlorine and chloramine in drinking water are far too nominal to affect most plants in any serious way, even in an organic grow. The article is very clear that hydroponics systems may be different because of the sensitivity of plants growing hydroponically.
The basic idea that these chemicals are essentially harmless to many plants is backed by the University of Nebraska and a few different studies are cited.
What exactly is chloramine? It’s just chlorine with ammonia added to make the chlorine’s effects more stable and therefore last far longer. It will not simply evaporate over a few hours like chlorine would, it actually takes months or more!
Here’s some brief excerpts about levels of chloramine and chlorine and removing both chemicals, quoting from the article:
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Levels of Chlorine in Tap Water
The World Health Organization suggests using no more than 5 ppm (mg/L) of chlorine in drinking water. “Most people will smell or taste the chlorine at higher concentrations.”
Levels of Chloramine in Tap Water
The Center for Disease Control (CDC) suggests a limit of 4 ppm for chloramine. Most municipalities in North America have values below this level.
Toxic Level of Chlorine for Plants
A lot of greenhouse horticulture uses municipal water and chlorine toxicity is a concern for them. They have determined that levels under 150 ppm are not a concern for toxicity, in potted ornamental plants. Hydroponics might be different
Does Chlorine Kill Soil Microbes?
Since chlorine is used to kill microbes, will it also harm the microbes living in soil or compost piles?
Chlorine tends to bind to clay particles and organic matter which makes it much less toxic to microbes. Soil and compost piles contain huge amounts of microbes and even though some are killed they quickly repopulate. Any effect that does occur is short lived.
“In one study, researchers continuously applied highly chlorinated water to soil for 126 days. Two days after they stopped, the soil microorganism populations reached pre-treatment levels at all depths of soil.” This is just one example of how quickly microbes grow in soil and why adding things like biostimulants, humic acids and mycorrhizal fungi have no effect.
Another study measured the chlorine concentration that is needed to kill all the microbes in the top 6″ of soil. A concentration of 65 ppm would be needed, a value that is more than 10 times higher than any drinking water.
Chlorine in tap water does kill a few microbes, but it has little effect on the total population, and numbers quickly rebound.
Removing Chlorine and Chloramine from Water
Both chlorine and chloramine can be removed from water by boiling. Removing half of the chloramine (half-life) takes 30 minutes, while doing the same for chlorine takes 2 minutes.
Chlorine will also offgas from water just by letting it sit, but chloramine does’t in any reasonable period of time . The latter can be filtered out with a special charcoal filter.
——————————————————-
Hopefully copying and pasting those excerpts isn’t breaking any rules.
I’m curious if anyone here has done or found any studies themselves, but it seems to me it shouldn’t matter if it’s cannabis or another plant, the organisms in the soil and their health are the key concern.
I will also point out from a practical perspective that keeping open water containers takes up space, adds humidity to a room, without intervention the water will be less oxygenated after standing, and it’s a spill waiting to happen.
All this makes me reconsider keeping buckets of water in the veg room and a garbage can full of water outside the flower room.
I really think the pros of more oxygenated water fresh from the tap far outweighs the con of potentially killing a very small amount of microbes in the soil for a very short time.
Thoughts or experiences?
Here’s the link to the original article:
www.gardenmyths.com
To summarize, the levels of chlorine and chloramine in drinking water are far too nominal to affect most plants in any serious way, even in an organic grow. The article is very clear that hydroponics systems may be different because of the sensitivity of plants growing hydroponically.
The basic idea that these chemicals are essentially harmless to many plants is backed by the University of Nebraska and a few different studies are cited.
What exactly is chloramine? It’s just chlorine with ammonia added to make the chlorine’s effects more stable and therefore last far longer. It will not simply evaporate over a few hours like chlorine would, it actually takes months or more!
Here’s some brief excerpts about levels of chloramine and chlorine and removing both chemicals, quoting from the article:
——————————————————
Levels of Chlorine in Tap Water
The World Health Organization suggests using no more than 5 ppm (mg/L) of chlorine in drinking water. “Most people will smell or taste the chlorine at higher concentrations.”
Levels of Chloramine in Tap Water
The Center for Disease Control (CDC) suggests a limit of 4 ppm for chloramine. Most municipalities in North America have values below this level.
Toxic Level of Chlorine for Plants
A lot of greenhouse horticulture uses municipal water and chlorine toxicity is a concern for them. They have determined that levels under 150 ppm are not a concern for toxicity, in potted ornamental plants. Hydroponics might be different
Does Chlorine Kill Soil Microbes?
Since chlorine is used to kill microbes, will it also harm the microbes living in soil or compost piles?
Chlorine tends to bind to clay particles and organic matter which makes it much less toxic to microbes. Soil and compost piles contain huge amounts of microbes and even though some are killed they quickly repopulate. Any effect that does occur is short lived.
“In one study, researchers continuously applied highly chlorinated water to soil for 126 days. Two days after they stopped, the soil microorganism populations reached pre-treatment levels at all depths of soil.” This is just one example of how quickly microbes grow in soil and why adding things like biostimulants, humic acids and mycorrhizal fungi have no effect.
Another study measured the chlorine concentration that is needed to kill all the microbes in the top 6″ of soil. A concentration of 65 ppm would be needed, a value that is more than 10 times higher than any drinking water.
Chlorine in tap water does kill a few microbes, but it has little effect on the total population, and numbers quickly rebound.
Removing Chlorine and Chloramine from Water
Both chlorine and chloramine can be removed from water by boiling. Removing half of the chloramine (half-life) takes 30 minutes, while doing the same for chlorine takes 2 minutes.
Chlorine will also offgas from water just by letting it sit, but chloramine does’t in any reasonable period of time . The latter can be filtered out with a special charcoal filter.
——————————————————-
Hopefully copying and pasting those excerpts isn’t breaking any rules.
I’m curious if anyone here has done or found any studies themselves, but it seems to me it shouldn’t matter if it’s cannabis or another plant, the organisms in the soil and their health are the key concern.
I will also point out from a practical perspective that keeping open water containers takes up space, adds humidity to a room, without intervention the water will be less oxygenated after standing, and it’s a spill waiting to happen.
All this makes me reconsider keeping buckets of water in the veg room and a garbage can full of water outside the flower room.
I really think the pros of more oxygenated water fresh from the tap far outweighs the con of potentially killing a very small amount of microbes in the soil for a very short time.
Thoughts or experiences?
Here’s the link to the original article:
Chlorine, Chloramine and Plants - Everything You Need to Know
You have probably heard that chlorine in tap water is harmful to plants. Some cities have switched to using chloramine in tap water and that is also a concern for plants because it is much harder to remove before watering indoor plants. What is the difference between chlorine and chloramine...
www.gardenmyths.com
