Vinegar is acidic, so it might help in that it keeps cacti soil slightly acidic for acid lovers.

Here we go again ...
(This is something that has been debated many times on different forums etc.)

Yes, many growers, including me, add acids to tap water before we use it, both to obtain a more suitable pH of the water and to avoid formation of limescale in the soil.

Usually 1 tablespoon of vinegar per gallon of tap water is recommended. The text you linked says per 5 gallons, which points at problem: the amount is not a universal constant, it depends on the amount of dissolved alkaline salts (mostly calcium/magnesium carbonates) in the water. You should preferably have some information about the chemistry of your tap water before doing this, at least the hardness. The subject is complex, and while I easily could write several pages on it I don't know all details, especially not how cactus roots respond to water that is too acidic (i.e. after an overdose of vinegar), and how fast this acid is neutralised by different soil types.

It is not clear why the water is spoiled if stored for more than one day. The added acid might serve as food for microorganisms, but I have never noticed any smell or other ill effects of longer storage (a few days).

The common reason why people let the water sit for a day or two is to get rid of chlorine. If there is a surplus of carbon dioxide in the water, some limescale may precipitate as well.

Ooops! Sorry, I didn't know it had been brought up before. I did do some surfing online last night to try and understand why it said most cacti like acidic soil.
Guess it depends on the type of cactus also, some like alkaline soil.

Anyway, it was something new for me and I wondered about it is all.
Thanks!

I don't remember if it has been brought up here, but I have seen it discussed before. It was not a criticism, I know how difficult it can be to find old threads and other information on a particular subject.

Some cacti are said to like acidic soil, especially epiphytes. A few need a alkaline soil (information from skilled growers, but I don't know why they think so). Many like a pH around 6.

I've used purified water for years on my plants (I have a reverse osmosis purifier...) All I add to my water is Eleanor's VF-11 (which is a very dilute fertilizer and mostly a shot of micronutrients) which is supposed to balance PH, and a little hydrogen peroxide to aid in oxygenating the roots.

Denise in Omaha

I might add that sulfuric, citric and nitric acid are used as well, but acetic acid (vinegar) is the most common as it is readily available as a stable, non-toxic and relatively non-corrosive solution.

denise -

I am curious - have you gotten the miraculous results that are claimed for Eleanor's VF-11? Thinking about trying it...

Tom

I use vinagar because I have hard water. Well water (soft water) that the Huntington uses, makes a big difference. Some succulents grow in shale, others ancient coral beds, some sandstone, granit, quartite. Can we please all of them? We have pumice available and that helps, Eastern states I have been told do not, so we need to adjust and use what we have. It would be nice to be given instructions on just how to do that. Norma

Can we clarify terminology a bit? "Hardness" is different than pH (acidity). "Hardness" is mineral content, general hardness gH --various minerals, kH -- is calcium carbonate.

kH and gH are measured in ppm parts per million.

pH is acidity measurement. It is measured on a scale of 0 - 14 with 14 = extremely base and 1 = extremely acid.

Generally, very soft water (low gH/low kH) is lower in pH, but not always! You could have highly acid water with low or high gH, high or low kH, highly base water with high or low gH and kH, etc.

Here the water has almost zero kH, By law your water company should publish the average numbers of your average kH, gH, pH, iron, etc.

I really don't think hard water will stop them from growing, but will stop them from growing as well as they could. You can also correct this by the soil you use. And I will not get into a soil discussion with anyone. Norma

> "Hardness" is mineral content, general hardness gH --various minerals, kH -- is calcium carbonate.

General hardness is approximately "dissolved things that precipitates soap", in tap water this means almost exclusively calcium and magnesium. "Various minerals" is more close to another parameter, TDS (total dissolved solids).
Carbonate hardness is not calcium carbonate, it is the bicarbonate and carbonate content (in tap water), if the counterion is calcium or something else doesn't matter, as long as it not too acidic (like H+). The result is just recalculated to the corresponding concentration of CaCO3, for convenience, I guess. I just find it confusing, lots of people misunderstand it.

One thing we do seem to know is that all plants prefer acidic rain water, even those that "prefer" soil pH that is basic.

x

Ah, the next step. Still, a correct amount is needed. Adding a volume of vinegar calculated for pure water will not do much difference in the same volume of hard water.

I use tap water, straight from the hose. If I bother to water the cactus/succulents/relatives at all.

If you don't get a report from your city on the water check their webpage. It's a federal law that it has to be posted and available.

You wanna get really grossed out take a class on water, or an irrigation class. I still won't drink the stuff!
Tally HO!

Regardomg Eleanor's V-F 11 I have used it for years, I'll swear by it. Vinegar in water was told to me by professional growers at the last Convention. Norma

Here's some reading on the topic by the guy who suggested the theory based on his own findings.
tjicken - What other forum did you discuss this on? if you don't mind me asking. you can PM me if necessary.

Here is a link that might be useful: Cactus and Alkalinity.pdf

I did not say that I discussed it, but I have seen threads on the subject on CactiGuide and BCSS (and here). Maybe it is not as common on forums as I recalled it, but it is something I often see mentioned in web pages/documents such as the one you linked to and the ubiquitous "Recognition and Culture of the Holiday Cacti", it might have affected my memory.

I love VF-11. Or more to the point, my plants seem to love it. It's worth every penny. I use it year round, both water it in and foliar feed (though I'm not sure how useful that is with succulents...) I order it 4 gallons at a time directly from Eleanor, though you can get smaller quantities to try from various on-line retailers.

Denise in Omaha

I use one third peat moss with my cacti mix.Have many cacti 15years old,they seem to do well with this mixture.The water is 8ph and using peat moss it brings it down. fRANK

hello, when the article was in the journal I brought it up in this forum and asked for opinions.I've been using vinegar since then and it seems to make my caudexes more green and healthy.and I think its been talked about in the journal a couple of different times.I just use maybe 2 drops per gallon. joe

joeplant, what is the hardness of your water?

tjicken, I don't know and I don't think it matters because the article also states that lightning varies the ph down to as low as 4.6 so when ever it rains the rain is different ph's and I would'nt doubt that your water hardness varies a little. joe

hey tjicken, I wasn't attacking you :-) I was just curious as it has been discussed on a few of the other groups I belong to.

One things for sure - ever since I started fooling around with adding vinegar to water a few years back, my pots no longer accumulate a calcium crust along the edges.

I cannot say for sure that I have noticed better growth, but certainly no harm has been done.

x