Tap water: acidified or boiled? Or both?

[From0to10in2weeks]

Hi,

I am wondering what is the better treatment when using tap water: acidifying or boiling it? In both cases, (hydro)carbonates get removed albeit in different ways. When boiling tap water the carbonates precipitate as calcium carbonate. That process effectively removes calcium ions as well whereas they stay in solution when acidifying.

So, how important are calcium ions for plant health/growth?

Thanks. Best.

[mmcavall]

Not directly answering your question about the importance of calcium ions for the plants (which I would like to know) I would say that boiling all tap water would be very complicated. You would give up the idea after a while. I use vinegar in my tap water and it is simple and easy.

[From0to10in2weeks]

Not directly answering your question about the importance of calcium ions for the plants (which I would like to know) I would say that boiling all tap water would be very complicated. You would give up the idea after a while. I use vinegar in my tap water and it is simple and easy.

You're of course absolutely right. That's why I used citric acid so far to acidify the tap water. But there are suggestions out there that boiled tap water or water that has been standing around for a while also are suitable, and preferable over untreated tap water. But the Ca content should be different compared to using acid to adjust the pH.

Now, does it matter?

Best.

[Steve-0]

Newbie answer: We have hard water here in the western USA. So tap water is out. I collect snow in winter, rain in spring and fall, creek, river or pond water when other sources aren't available. I got this from online cactus care sources. Pond water needs no fertilizers added. Snow and rain get some very diluted low nitrogen food added. Haven't used any acidifying agents in my waters yet. Should I? So far so good.

[keith]

Any excuse to not work.

I ran some quick experiments boiled water and tested it no change form TAP water about 7.5-8.0

tested Brita about a 5.0 ???? It does have a new filter activated Charcoal I think ?

tested distilled water about a 6.0 so tester is working

tested old Brita ( wife gave me to water my cactus with ) about a 7.5 it has a old filter so its not even working.

When I test the AC condensation it is about a 5.0 which I always thought was weird.

Conclusion somethings wrong with this new Brita filter in the past it always just lower the PH a color scale going from a 8 to a 7.

Its radically screwed up But why ? when I test the boiled water I see a PH of about 8.0 which was about 5.0 when it came from the Brita so around here boiling water increases PH.

[Steve Johnson]

I am wondering what is the better treatment when using tap water: acidifying or boiling it? In both cases, (hydro)carbonates get removed albeit in different ways. When boiling tap water the carbonates precipitate as calcium carbonate. That process effectively removes calcium ions as well whereas they stay in solution when acidifying.

So, how important are calcium ions for plant health/growth?

I don't know if this answers your question, but the following article is what got me into acidifying my tap water starting way back in 2012:

https://docs.google.com/file/d/0Bwfo_53 ... l=en&pli=1

This article is incredibly detailed, and to be honest, all the chemistry being discussed there was (and still is) way over my head. If you have a good grasp of chemistry, the answer you're seeking may be in there somewhere.

[MikeInOz]

From0to10in2weeks post_id=378506 time=1600772010 user_id=16812]
Hi,

I am wondering what is the better treatment when using tap water: acidifying or boiling it?

Acidifying it. Boiling will do next to nothing.

So, how important are calcium ions for plant health/growth?

Extremely. Calcium deficiency will result in a proliferation of root rot diseases among many other disorders.
One way or another, your plants MUST receive calcium. This can be from the water, from the soil or from additions or from all three. There is no such thing as too much. The important thing is to keep the pH under control and this is done by the use of acids (if needed) or a p/mix adjusted to the correct pH by the use of various ingredients and kept there (within reason).

[From0to10in2weeks]

https://docs.google.com/file/d/0Bwfo_53 ... l=en&pli=1

This article is incredibly detailed, and to be honest, all the chemistry being discussed there was (and still is) way over my head. If you have a good grasp of chemistry, the answer you're seeking may be in there somewhere.

Thanks. Now, I am a PhD Chemist but it's been a few decades since I looked at such basic chemistry. That being said the discussion in the paper is not at all clear to me either. It seems like a rather circular argumentation. I don't have the time at the moment to deep dive this. If I get around to it I'll provide a hopefully clearer description here.

That being said I agree with their suggestion to use vinegar (acetic acid) or citric acid instead of the other acids. Both for the reasons they list (no need to account for changes to N/P ratio and the formation of soluble salts) but also safety. Especially, if you're using conc. sulphuric acid make sure to use proper safety PPE and procedures (add acid to water!).

Needless to say the authors don't gain any favours with me making statements about the definition of the pH value like "This is an odd number invented by chemists to confuse people.".

[From0to10in2weeks]

tested Brita about a 5.0 ???? It does have a new filter activated Charcoal I think ?

In addition to activated Charcoal, the Brita filters contain an ion-exchange resin. This "absorbs" soluble metal ions and releases protons (H+) into the water. That's why it becomes acidic. So, you can actually monitor when you should replace the Brita filter by measuring the pH value of the filtered water.
That being said I am surprised that it lowers the pH to 5. Seems like a lot. Remember, the pH scale is logarithmic. So, a change in one pH unit corresponds to a change of 10x in the concentration of H+ or OH-.

[From0to10in2weeks]

So, how important are calcium ions for plant health/growth?

Extremely. Calcium deficiency will result in a proliferation of root rot diseases among many other disorders.

Thanks for the clarification. Best.

[keith]

Thanks. True ? A Brita filter will acidify water in other words release protons (Hydrogen atoms) in the water. My PH tester says yes but usually only a one color bar change like from a PH 8 to a 7 this one is extreme.

Soil will buffer any PH change but I don't want to pour low PH water directly on my cactus and now I'm not even sure I want to make coffee with it .

Vinegar is a good weed killer doesn't kill the roots but sure kills the leaves.

[From0to10in2weeks]

Thanks. True ?

Yes. You can go to the Brita website and read it for yourself. Or read about ion exchange resins/filters.

... release protons (Hydrogen atoms) in the water.

Not quite. The molecule that actually exists in acidified water is H3O+. In other words a water molecule H2O that carries an excess positively charged hydrogen ion. It's common to describe it simply as H+, e.g. a hydrogen atom that lacks its electron. A hydrogen atom is neutral (= carries no charge). And in fact, under common conditions hydrogen (gas) itself only exists as a molecule of two hydrogen atoms bound to each other. H2. But that doesn't play a role in here.

My PH tester says yes but usually only a one color bar change like from a PH 8 to a 7 this one is extreme.

As I said, yes, that seems extreme. What pH tester do you use?

Best.

[From0to10in2weeks]

...I'm not even sure I want to make coffee with it .

And oh, if you're concerned about using Brita filtered acidic water for your coffee you really don't want to measure the pH of some other foods you might be consuming. Fruits, pasta sauces, salad dressings etc.

[keith]

"And oh, if you're concerned about using Brita filtered acidic water for your coffee"

Coffee at home makes me sick coffee at work I'm OK so IDK ? Werid. And thanks for the chemistry I usually just add vinegar to water right out of the city pipe to my hose bib. I have used Brita on occasion with no vinegar for small watering of small seedling cactus. Usually they both test the same on my "General Hydroponics pH Test Kits make pH testing easy. Simply fill a test-tube halfway with nutrient, add a few drops of pH Test Indicator and observe ." tester kit thing.

And sometimes I just water some cactus and succulents with no vinegar at all and I cant tell the difference. I don't think its as big a deal as getting the water scheduled right and the soil composition right . Maybe after 10 years calcium carbonate will build up in the pot if its not flushed out once and awhile ?