Understanding Effects Of Water With High Alkalinity

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jumpincactus

jumpincactus

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Did you know that feed water with high alkalinity will substantially raise the medium Ph in the rhizopshere no matter what the Ph of the input water is???

There seems to be a lot of misunderstanding over ph and alkalinity. I seem to remember posting on this a while back but this article seems a tad more informative and easier to understand.

I would think this info to be more useful to those of us that rely on groundwater aquifers or well water supplies that dont get tested or get treated to adjust total alkalinity.

Water Quality: pH and Alkalinity

Recently, some growers have expressed concern about the "high pH" of their irrigation water and its potential adverse effects on plants. The purpose of this article is to allay some of these concerns by pointing out the difference between "high pH" and "high alkalinity".

Alkalinity and pH are two important factors in determining the suitability of water for irrigating plants. pH is a measure of the concentration of hydrogen ions (H+) in water or other liquids. In general, water for irrigation should have a pH b etween 5.0 and 7.0. Water with pH below 7.0 is termed "acidic" and water with pH above 7.0 is termed "basic"; pH 7.0 is "neutral". Sometimes the term "alkaline" is used instead of "basic" and often "alkaline" is confused with "alkalinity". Alkalinity is a measure of the water's ability to neutralize acidity. An alkalinity test measures the level of bicarbonates, carbonates, and hydroxides in water and test results are generally expressed as "ppm of calcium carbonate (CaCO3)". The desirable range f or irrigation water is 0 to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most plants.

Irrigation water tests should always include both pH and alkalinity tests. A pH test by itself is not an indication of alkalinity. Water with high alkalinity (i.e., high levels of bicarbonates or carbonates) always has a pH value ÷7 or above, but water with high pH doesn't always have high alkalinity. This is important because high alkalinity exerts the most significant effects on growing medium fertility and plant nutrition.

High pH and High Alkalinity Effects on Plant Nutrition
Potential adverse effects. In most cases irrigating with water having a "high pH" ( 7) causes no problems as long as the alkalinity is low. This water will probably have little effect on growing medium pH because it has little ability to neutralize acidity. This situation is typical for many growers using municipal water in Massachusetts, including water originating from the Quabbin Reservoir.

Of greater concern is the case where water having both high pH and high alkalinity is used for irrigation. In Massachusetts this situation is most common in Berkshire county. One result is that the pH of the growing medium may increase significantly with time. This increase may be so large that normal lime rates must be reduced by as much as 50%. In effect the water acts as a dilute solution of limestone! The problem is most serious when plants are grown in small containers because small volum es of soil are poorly buffered to pH change. Therefore, the combination of high pH and high alkalinity is of particular concern in plug seedling trays. Trace element deficiencies and imbalances of calcium (Ca) and magnesium (Mg) can result from irrigating with high alkalinity water.

It is much more difficult to predict the effects of irrigating outdoor flower crops, gardens, and landscape plants with water having high pH and high alkalinity. On the one hand, in some parts of the United States, long-term irrigation of crops with water high in bicarbonates and carbonates has led to yield-limiting trace element deficiencies which must be corrected with special fertilizers. On the other hand, in New England, several factors probably act together to partially offset the effects of high alkalinity water. First, rainfall levels are relatively high and historically this has caused Ca and Mg ions to leach from the soil. These are replaced with H+ and the result is acidic soil. Second, this acidification may be helped along by the rather acidic rainfall common in this region in more recent times. Third, acid-forming fertilizers also help counteract high pH and alkalinity.

Potential beneficial effects. For some greenhouse operators, water with moderate levels of alkalinity (30-60 ppm) can be an important source of Ca and Mg. With the exception of Peter's EXCEL and a few other fertilizers, most water soluble fertil izers do not supply Ca and Mg. Also, the Ca and Mg from limestone may be inadequate for some plants. Moderately alkaline water could be beneficial as a source of extra Ca and Mg for crops prone to Ca and Mg deficiencies (e.g., poinsettia).

Other Effects of High pH and High Alkalinity
In addition to nutritional disorders of plants, water with high alkalinity can cause other problems. Bicarbonates and carbonates can clog the nozzles of pesticide sprayers and drip tube irrigation systems with obvious effects. The activity of some pesticides, floral preservatives, and growth regulators is markedly reduced by high alkalinity. When some pesticides are mixed with water they must acidify the solution to be completely effective. Additional acidifier may be needed to neutralize all of the alkalinity. To determine if a chemical is affected by high alkalinity, carefully review the product's label. Unfortunately this potentially important information is not always printed on the label, so considerable extra effort may be necessary to find the inf ormation. A call to the manufacturer will probably be needed for most chemicals.

Acidification of High Alkalinity Water
Many greenhouse operators inject acid (e.g., phosphoric, nitric, or sulfuric acid) into water with problematic high levels of alkalinity. Acidification of water having high pH but low alkalinity is rarely necessary. The use of acid injection sh ould be considered very carefully for several reasons. First, it is an extra step in production which will require additional materials and equipment. Second, acids are dangerous to handle and may damage some injectors and piping systems. Third, phosphoric or nitric acid are sources of P and NO3, so the regular fertilizer program may need to be modified to take into account the addition of these nutrients. This would depend on how much acid must be used to neutralize the alkalinity and reduce pH. Fourth, sometimes acid injection causes the solubilization of normally precipitated (unavailable) forms of trace elements resulting in levels toxic to plants.

The amount of acid required to reach the desired pH (i.e., neutralize alkalinity) is determined by laboratory titration of a water sample with the appropriate acid or by a calculation procedure. Some "fine-tuning" may be needed later when actual inject ion is started. Acid is always injected prior to the addition of fertilizer or other chemicals.

Prepared by Douglas Cox
Plant and Soil Sciences
University of Massachusetts

https://ag.umass.edu/fact-sheets/water-quality-ph-alkalinity


Heres a second link for another look http://www.greenhousegrower.com/pro...ant-nutrition-irrigation-water-alkalinity-ph/
 
Seamaiden

Seamaiden

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Did you know that feed water with high alkalinity will substantially raise the medium Ph in the rhizopshere no matter what the Ph of the input water is???
Yes. :D And thank you so much for posting this. Many organic growers are stuck in a paradigm that insists no need to pH. I am here to tell you, them, and anyone else willing to listen that is not always true, especially if you're working with a source water that's high in hardness, specifically carbonate hardness, and alkalinity.

Fishies love me.
 
jumpincactus

jumpincactus

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Yes. :D And thank you so much for posting this. Many organic growers are stuck in a paradigm that insists no need to pH. I am here to tell you, them, and anyone else willing to listen that is not always true, especially if you're working with a source water that's high in hardness, specifically carbonate hardness, and alkalinity.

Fishies love me.
Lady Sea I could not agree more. Good to see you BTW. :cool:

I am still looking for a graph I had that shows just how high alkalinity in feed water can raise the ph in our grow mediums. It is pretty astounding. Can drive soil ph levels up into the 8's and 9's
Wish I could find the dang thing.
 
jumpincactus

jumpincactus

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Good day to you bro hows the weather your side of the pond? We are getting hammerred due to El Nino year. Bad for some but Cali really needed a break with some rain and snowpack
 
Ecompost

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I think we also need to be careful to consider the relative biology of acidic or alkaline soils systems. In soil profiles where organic matter is restricted, eg sandy, early basic soil systems, we would see a proliferation of bacteria, these being capable of living in such habit above say a fungus which would not. Bacteria, specifically Nitrate fixers, have bio film excretions that are in the pH range above 7.0. In order to convert N2 to No3- a pH greater than 7 is required. Hence microbes which have existed for billions of years, have developed conditions that better suit the function. As more plant matter is able to gain a hold, we will find more and more fungi appearing. These fungi release organic acids, and as such tend to exist in profiles of less than 6.5. Now since fungi can ultimately consume a wider diet, it is such that given time, all soils would be fungal dominant and so promote perennial plant life as in the case of forests.
How this manifests for us, short day growers, is still being researched, but we can know as a foundation, short lived plants tend not to form relationships with fungi as they wont be around long enough for this to be mutually beneficial and so bacteria are the key.
So knowing bacteria prefer higher pH condtions, above 7.0, and fungus acidic, what does this mean for growers using biology versus those not?
If I take samples of rhizo pH in any one container, I will get about 7 or so different readings, from pH 5.6 to pH 11.0.
Growers not modulating the environment with biology, must consider pH as a priority, they must also find a way to scavenge free radical ions which accumulate in non biologically active, humate weak media, hence the use of flushing. A most bizzare concept of indoor growing if you ask me.
We can know that soils are typically - in charge and so continued use of Cations will likely impact soil charge. - soil charge is the only thing preventing collapse, we destroy the charge, we usher in collapse, we drive out air, we kill fungus, we make pH swing about 7.0+. Water fails to penetrate, we get hydrophobic compaction and zero growth, we add lime as per university instructions and we add to the cation disaster and put increasing amounts of lime via frequency and quantity. We are idiots, we don't learn very well and we have bad habit that are not founded in science but in the human desire to mask not fix. A university still suggesting lime as an answer to soil acidification should be closed as a dangerous proganda channel and not centre of open learning. Rant over. But awesome post and extremely thought provoking. eco
 
jumpincactus

jumpincactus

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I don't use lime. And you are correct, universities a long time ago stopped really teaching students to think outside the box and question the way things have always been done. I am with you 100% I don't nor will I use liming to adjust my substrates Ph thats what bacteria and fungus were designed to do.

It is going to take a long time to get the traditionalists to drop their insane ways and get right with the planet and the world above and below our feet. All the answers are there if we can open our eyes and make the change. Mother Earth is the greatest biological engineer there is.

Like to see someone argue that........... :D
 
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Ecompost

Ecompost

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I don't use lime. And you are correct, universities a long time ago stopped really teaching students to think outside the box and question the way things have always been done. I am with you 100% I don't nor will I use liming to adjust my substrates Ph thats what bacteria and fungus were designed to do.

It is going to take a long time to get the traditionalists to drop there insane ways and get right with the planet and the world above and below our feet. All the answers are there if we can open our eyes and make the change. Mother Earth is the greatest biological engineer there is.

Like to see someone argue that........... :D
I will pass picking that one up mate LOL. I love the fact I can inject biology in to compaction layers and really fix the root of soil pH flux. If we google acid soils, we will get 2000 results say lime. You are quite right mate there is a lot of work to do. I try to get people to use Humates, drop out lime, drop out espsom which is also bollocks but used all the time with no data to back it. :-)
 
scubascrog

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I just added slow release lime to my mix of soil that I'm transplanting into because my runoff is constantly dropping below 5. I add microbes with humics and yucca but I think my water needs to sit out longer, it comes out at 8.5 and drops to 7.5 overnight, usually ph down after 2 days still to get it to 6.8, then runoff comes out with a massive cal-mag lockout and a runoff of 5 or lower. they were fluctuating when they were on water only, now that I am feeding them they seem to be doing better. just going to slowly cut out cal-mag until I see the plants reach the dolo after I transplant. also I didnt use extra perlite in the 1 gallons and I'm using 30% more in the 5 gallon transplant.
 
Ecompost

Ecompost

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y
I just added slow release lime to my mix of soil that I'm transplanting into because my runoff is constantly dropping below 5. I add microbes with humics and yucca but I think my water needs to sit out longer, it comes out at 8.5 and drops to 7.5 overnight, usually ph down after 2 days still to get it to 6.8, then runoff comes out with a massive cal-mag lockout and a runoff of 5 or lower. they were fluctuating when they were on water only, now that I am feeding them they seem to be doing better. just going to slowly cut out cal-mag until I see the plants reach the dolo after I transplant. also I didnt use extra perlite in the 1 gallons and I'm using 30% more in the 5 gallon transplant.

What is the media bro?
I would only apply bacteria, no fungus when you input extra biology, use Bac Sub and other Azobac etc. I would use a humic only, no fulvic. A Potassium Humate will likely work a bit better than a fulvic acid at raising the pH. Do you have lots of Al+++ hanging about, it will be in your plant if you don't have enough bacteria at that low pH range. Trichoderma will help you plant limit the uptake of Aluminium, Cadmium etc? I would get some kind of filter for the water, do you use one? Why would you add pH down at all if you know the media is acidic? If you add humates, you don't need pH adjustment.
Are you using too much P? what are your P inputs based on PPMs?

Perhaps a mulch will be the answer, depends on your set up of course
 
scubascrog

scubascrog

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I was just using roots 707 and water when I started having these issues, I have them feeding now on age old fish and seaweed 3-2-2 but I think its the coco content in the 707 thats dropping it. now that they have nutrients in the soil it seems to be stabilizing, my calcium content wasn't there in the soil after a lockout so it doubled down on the effect on the lower leaves, (main stalk leaves with the shoot removed big whut whut) but they are getting half doses of cal-mag every watering now until I transplant, then i'll slow off the cal-mag once the roots reach the dolo lime.
And I meant bacteria, Im not using fungus, I use root by RX green solutions jsut added with my last feed (yesterday) fish and seaweed and cal-mag. I will be using PHOS Indonesian seabird guano 0-12-0 in act with this stuff in flower. as well as terpinator for k, does this stuff have k? I though seaweed extract has some in it.
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