Hi
Not sure were you're located in florida but in my area alkaline water is no problemo,just turn on the tap lol
Obviously it would depend on the plant. Blueberry is a great example that one that would hate it lol. There are many others. I water most of my plants with rainwater particularly epiphytes. Some are notoriously finicky while others don't seem to mind. One water source is much easier to manage. Yard plants are watered from the tap though again in certain species you can see a difference.
If you want to grow acidic plants avoid alkaline sources gary

Sounds like this company is trying to take someone's hard earned money !
Rain water is naturally slightly acidic . That's why you see such dramatic improvements in plants after a good rainfall .
I could not find any info to support the claim of the company you cited . Here is what little science based info I could find :

Alkalinity or hardness is a measure of water's ability to neutralize acids while the pH of the water will indicate the actual acidic or basic nature of the water. Thus it is important to know not only the pH of your water but also the alkalinity in order to determine the influence irrigation water will have on changing media pH during the crop cycle. Alkalinity is generally presented as ppm hardness or as milliequivalents/liter calcium carbonate (meq CaCO3). Alkalinity levels of 2 to 4 meq CaCO3 (100 to 200 ppm) are considered normal. Lower levels may result in undesirable medium pH depression during the crop cycle and higher levels may result in media pH levels above desired levels (> pH 7).

Here is a link that might be useful: Irrigation and Water Quality

Out here in the high deserts of the mountain west the water is often quite alkaline. Using a aquarium dip stick test our city water is about pH8. Because water here is so expensive people don't grow a lot of stuff but I have never seen any obvious harm, or benefit, to plants attributable to the water. Some aquarium fish cannot handle it. My late in-laws grew berries of some sort.

Alkaline water?....Come here to Cornville AZ I will give you all you want. I'm on a private well and grew my garden the first year with compost, manure, and well water. The first year everything went well, the second year everything was stunted. Okra grew a whopping 8 inches tall, cukes were yellow and hard at 2 inches, and even Zuccinni which will grow everywhere, was hard and yellow even at a few inches long. They looked and felt like gourds. I did a pH test before first year planting, 7.1 at the end of second year 9.2. Left the ground fallow for 2 years and will try it again, with a filter

It all depends on your soil and its buffering capacity. If your soil pH is below 6, then using alkaline water may be helpful. If your pH is higher, it won't and may even be detrimental.

AZ Native--what else is in your water? Just high pH shouldn't generate that kind of rise. Do you have high sodium also? getting a pH that high can indicate salting the soil out. You may need to flush the soil to get rid of the salt and if your water isn't too high in sodium and dissolved solids, use more water to irrigate to flush the ground on an annual basis to take the salts down and out. Talk to the guy in the home-made electric car that runs around town--he grows quite a garden too!

Yes beeone, my water has so much stuff in it I have to take the water supplies off every sink in the house every six months or so and clean them of the salts or they will leak at the threads. I was gardening in raised beds so the affected soil is contained. I will spread it across the yard and dig it in to 'dilute' the problem soil, and use regular rows for planting next year. With a filter on the soaker hose supply. Thx for your input

I contacted my water dept and found out my PH is very high(no measurable acid) and the alkalinity is very high as well. I add a teaspoon of acid per gallon of water (in a miracle grow hose end sprayer) and the plants have really changed for the better, very deep green, much higher bloom and growth rates.

Alkaline Water + Blueberry = slow dance of death , unless you treat the water with something to bring it back to PH7 or less.

Alkaline water is not good for most plants. Slightly acid is best for most. It is easier on pipes then acid, and some municipalities will deliberately raise pH of water to reduce maintenance. If your soil is too acid it can help. In pots, it's a nightmare, locking out nutrients such as magnesium. In sandy soils, not usually a major issue as salts don't often build up in sand due to high drainage.

We have fairly high PH water (8.0 or so) here in Central IN. We've always added about 1/2 teaspoon of sulfuric acid to our irrigation water for vegetables - Makes a huge difference, for sure.

I finally got an old dug well going a couple months ago and have really gone wild with giving my water-starved plants and trees some moisture. Some are thriving and others, while initially responding well, are responding with smaller leaves, almost shriveled in some cases. The citrus trees don't seem to like the water whereas pineapple guava, the nut trees, geraniums, avocados, etc. do seem to like it. Bamboo I'm not sure yet. Lots of yellow leaves but this could be leftover from this summer's drought.

Besides watering the ground around the plants I've been shooting streams of water onto the leaves and branches for foliar feeding. Maybe that's not a good idea in this situation.

My groundwater is known to have high levels of Total Dissolved Solids, notably magnesium and iron and other salts. It's possible I've got some chemicals in the water too - need to get it tested and see just what's in it and what the pH is.

Everything has always responded well to city water so obviously there's something in the well water which isn't good, at least for everything.

If anyone knows of other forums on Gardenweb which relate to well water for irrigation, please point me there. The search function on Gardenweb seems very much a shotgun approach.

Thanks,

Mike

i have found an excellent primer explaining in pretty clear language the relationship between soil PH, water alkalinity, effect of various fertilizers, and how PH effects absorbtion of var. nutirients,etc.
some plants prefer the extremes of PH, but most fall somewhere closer to the middle. blubs are acid outliers.
i've also seen articles talking about how some plants can move the PH of the soil towards more alkaline or more acidic (never knew about that) - but it's not in this one.
it is for greenhouse/container growers, but it is highly applicable to garden growers too, i think.
tell me, what you think about it. i myself only garden in containers and mostly indoors, and i know i have hard water, and i never analyzed. but i might be moving into an area with alkaline water and wanted to understand the issues, if any. and apparently there are issues - but it's possible to correct them also by using various fertilizer formulations.

Here is a link that might be useful: soil PH-water alkalinity- correction with fertilizers

Since my last post I've observed that the plant that is responding in a bad way most obviously to getting a lot of my well water is golden bamboo. It's always grown prolifically and was suffering badly from lack of water. I've always been generous with watering everything (using city water) but have cut back a lot since last winter as the drought has gotten worse and water more expensive. Most of my yard plants and trees (except for citrus but others I'm not sure about since trees react slowly) seem to be okay with the well water, but not the citrus or the bamboo - which is a shame since I have a lot of bamboo.

I haven't gotten the water tested yet. I'm curious more than anything about what's in it. Actually correcting the issue may be impractical considering the quantity of water involved in one of my watering sessions. I use at least 500 gallons whenever I turn on the well pump. If the water is too alkaline I suppose I could dump a gallon of acid into the well before I turn the pump on. I'll have to look into this further as time goes by. Meanwhile I'm hoping we get some rain here in San Diego to flush the plants and soil. Nothing makes plants happier than rain.