Alkaline irrigation water and its effects on your growing media

[pinecone]

hey pine, perhaps your water has low alkalinity for it's pH reading too. the fact you also successfully recycle your soil means it's unlikely there is much build up of calcium in there.

I did a bit of analysis and I think you may be onto something.

Our city water is very alkaline. For this reason we run a water softener which makes the water pretty bad for growing plants in (so I'm told). In the summer I use rain water, but it is not practical to harvest snow and ice so in the cooler months I water my plants with the same water we buy for drinking at the store. I have purchased RO water also to save on cost, but with mulch and no run-off I have not been using enough water to justify the effort.

Anyway, I did some calculations from the nutritional label and have determined that my water has 84.4 ppm of Ca, which doesn't sound like a lot. For reference my city water comes out at 311 ppm calcium carbonate (CaCO3) and about 70 ppm Ca (they are listed separately on the report).

Pine

 

[mad librettist]

let's not go overboard.

the reason for the flaming was a persistent insistence that everyone needed to check pH. Hydro-store style growchem was being ported over to organics so that people had familiar rituals to see them through. The vast majority of people don't need to bother with pH. Further, the vast majority of organic growers will do more harm than good if using the pH pen.


Your soil has a potential for buffering. That is fixed in the moment. If your water includes enough alkalinity to overcome that potential, you will have problems.

Also, calcium carbonate in particular is harmful to any soil when used in excess. To really decide on how much lime he needs, someone with lots of it in the water needs to do some math. Lime may be totally unnecessary. Adding an acid, on the other hand, gives you something similar to the eggshells and vinegar trick on top of buffering it down.

imo its always a mistake to presume that one idea will work equally as well for everyone else as it does for you, or that some method will be the best one to use the world over. i think local conditions and knowledge need to be taken into consideration when deciding which methods to employ/

This is exactly what Fukuoka stressed. If anything needs to be the party line, this is it.

It's also true that more than one way to solve a problem may exist. For the problem of alkalinity, some steps need to be taken in the soil, in the water before it is used, or both. Showing that it can be done with either doesn't show it can't be done with the other.

VG, have you checked out the Luebkes? Using their methods, which includes tilling in green manure with a spade plow:

In a ten-year period, the organic matter content of a clay loam soil on their farm was changed from 2% to 15%
Following downwind fallout from the Chernobyl nuclear reactor accident, root vegetables raised on their farm were uniquely free of radioactive contamination in comparison to other farms in the region
The nitrate content of vegetables raised on their farm was significantly lower than conventionally-grown produce in Austria
Soil and compost samples on their farm have well developed humus crumb and high numbers and diversity of microbes, as revealed by a specialized light microscope

 

[mad librettist]

VG, doing this test would let us know way more than just water testing:

http://www.ibiblio.org/steved/Luebke/Luebke-compost2.html

Potential pH Test

The potential pH test is a simple method for determining the exchange capacity of a soil or compost sample. Indirectly, it is a measure of biological activity and degree of humification. This test is described by Struchtemeyer in Basic Properties of Forest Soils (7).

In brief, two samples are prepared. The first sample is diluted with distilled water. A pH reading of this sample will provide the actual pH. The second sample is diluted with potassium chloride (.1 Molar KCl solution). A pH reading of this latter sample provides the potential pH.

The degree to which potassium ions displace hydrogen ions on the soil or compost colloids in solution will be reflected in the difference between the actual and potential pH readings. This is an indication of the ion buffering capacity, or the cation exchange capacity, of the sample. When the pH readings are further apart, they are an indication of poor exchange capacity. The aim is to achieve as little difference as possible; less than 0.5 pH units for soils and 0.3 pH units for compost is ideal.

During the humification process, microbes are actively building long-chain polymers of polysaccharides and other molecules. Well-developed humus has numerous exchange sites and therefore holds hydrogen ions more tightly. The actual pH and potential pH readings will be close together and indicate a high degree of microbial activity, humus structure, and surface area. Conversely, pH readings with divergent numbers are an indicator of poor humus development.

 

[Scrappy4]

VG, just curious if you have tried gypsum as a liming agent? As I understand it can both raise or lower the ph of soil. I have pretty much replaced dolomite lime with gypsum, azomite, oyster shell, crab meal and so on.....scrappy

 

[VerdantGreen]

hey scrappy, i have been considering gypsum, but really i probably dont need any extra calcium in my mix as i suspect that i have build up problems that mean i cant really recycle my soil. dolomite at least is adding more in the way of magnesium than calcium.
but as i mentioned earlier in the thread, rock phosphate, high P guano (which is basically fossilized guano and pretty much rock phosphate afaik) and even bonemeal are all liming agents.
what im trying is reducing the liming agents and adding a light dose of manure based ferts to keep the nutrient levels up. i've also used just rainwater during my present grow to see what difference that might make.

its not like im getting problems with my mix as such, i just suspect that there is a build up of calcium from all the different sources including my tapwater.

 

[ixnay007]

I have major league hard water, extremely alkaline stuff, using it even after letting it sit for 24 hours I would end up with PH problems towards the end of flowering, after a bit of experimentation I found the best solution wasn't adding acid (as the water has some incredible buffering properties) but to cut it half and half with distilled water from my dehumidifier. I add a little lime to my mixes, but the tap water here requires "cutting", since then, I've got happier plants, as they like cal/mag in the water, just not as much as comes out of the tap.

 

[Bennyweed1]

Damn I add lime and gypsum to my soil. Issues like this really spook me out and make me stress a little bit. I have a fancy little pH pen I use to check my levels but am often surprised with the results. My tap water is 8.1 usually but after it goes through my RO/DI it not only comes out at 0.0 EC but a prefect pH of 6.3-6.8. It is hard to get a pH reading on such clean water because I think there is no electrical conductivity but once I brew a AACT the pH issue is solved. I have never had a AACT out of the prime zone of 6.5-6.8.

Now I dont know if that is because of the RO/DI filter or just the nature of AACT but the pH after brewing for 24hrs is always perfect.

 

[StrictlyHerb]

Hey verdantgreen!
I know this is a really old thread by now, but what you are talkin about here is exactly the situation im in!
My tapwater ppm is 140 (american conversion) and has a ph of 8!??

in other areas I've always grown in soil without major problems but here my plants yellow and wilt after 3 weeks of tapwater.
Ever since i bought strong acidic PH down i went over to coco with mineral ferts, and it just breaks my heart as the best ganja is grown from the natural soil.

Soo; how did you manage your alkaline water in soil? what did you do? Do you have a soil recipe to share?

Best regards

 

[jonhova]

hey scrappy, i have been considering gypsum, but really i probably dont need any extra calcium in my mix as i suspect that i have build up problems that mean i cant really recycle my soil. dolomite at least is adding more in the way of magnesium than calcium.
but as i mentioned earlier in the thread, rock phosphate, high P guano (which is basically fossilized guano and pretty much rock phosphate afaik) and even bonemeal are all liming agents.
what im trying is reducing the liming agents and adding a light dose of manure based ferts to keep the nutrient levels up. i've also used just rainwater during my present grow to see what difference that might make.

its not like im getting problems with my mix as such, i just suspect that there is a build up of calcium from all the different sources including my tapwater.

NECRO BUMP
I have the same problem as the last guy. what did you do to solve your 8.0 PH problems in recycled organic living soil? Are you still using 2 teaspoons per gallon of dolomite lime??

 

[VortexPower420]

Use citric acid to lower water to your liking.

Do it Everytime, you will not be disappointed.

In the winter my water changes and bicarbonates go up. Citric solves the issue.

 

[jonhova]

Use citric acid to lower water to your liking.

Do it Everytime, you will not be disappointed.

In the winter my water changes and bicarbonates go up. Citric solves the issue.

Is Phosphoric Acid ok? I have it laying around already.

Is Citric acid preferred?

 

[MedResearcher]

Good topic, sad its such an old thread. Maybe some new life will be pumped into it. Slownickel has a lot of information on a similar subject, some data from golf courses and gypsum use.

Our well water is pretty damn hard, a lot of calcium in it. Enough to to fill a hot water heater a foot or two with chunks of calcium once a year.


For years I used Earth Juice, to bring the PH down. Really struggled, because our mixing tank was 300 gallons, but I could easily use 1,000 gallons on a July day. Eventually I noticed none of my neighbors, similar water table, added nothing and had great gardens. So I stopped.


We do use compost, and compost tea. I have been avoiding coco as well, figure the peat decomposing helps to bring the ph down, so choose it over coco. So far has worked well, and no PH tinkering. The sulfur leaches out easily also, so needs to be watched since it does bring the PH back down. Last year we didn't need to add elemental sulfur, got it all from sulfates that we needed anyways.


Not sure I have any answers, mostly just stuff I have noticed. Earth Juice is very acidic, so for a small garden a tiny amount in the water will do the trick. Think it was like 1/2 tsp apx. Its good stuff anyways, the grow/bloom/catalyst all nice organic stuff.

Was told for a large irrigation system, industrial strength vinegar in a dosotron style in line passive tank is the organic route if you must lower the PH in the source water.

One year I may try that out, don't think it will be this one though.

Also read somewhere, bacterial dominate vs fungal dominate. One lowers the PH the other raises it a bit. So imagine if you4 fighting one way you could try to use teas or specific compost to shift it back. Mushroom compost vs green waste.

Mr^^

 

[jonhova]

Good topic, sad its such an old thread. Maybe some new life will be pumped into it. Slownickel has a lot of information on a similar subject, some data from golf courses and gypsum use.

Our well water is pretty damn hard, a lot of calcium in it. Enough to to fill a hot water heater a foot or two with chunks of calcium once a year.


For years I used Earth Juice, to bring the PH down. Really struggled, because our mixing tank was 300 gallons, but I could easily use 1,000 gallons on a July day. Eventually I noticed none of my neighbors, similar water table, added nothing and had great gardens. So I stopped.


We do use compost, and compost tea. I have been avoiding coco as well, figure the peat decomposing helps to bring the ph down, so choose it over coco. So far has worked well, and no PH tinkering. The sulfur leaches out easily also, so needs to be watched since it does bring the PH back down. Last year we didn't need to add elemental sulfur, got it all from sulfates that we needed anyways.


Not sure I have any answers, mostly just stuff I have noticed. Earth Juice is very acidic, so for a small garden a tiny amount in the water will do the trick. Think it was like 1/2 tsp apx. Its good stuff anyways, the grow/bloom/catalyst all nice organic stuff.

Was told for a large irrigation system, industrial strength vinegar in a dosotron style in line passive tank is the organic route if you must lower the PH in the source water.

One year I may try that out, don't think it will be this one though.

Also read somewhere, bacterial dominate vs fungal dominate. One lowers the PH the other raises it a bit. So imagine if you4 fighting one way you could try to use teas or specific compost to shift it back. Mushroom compost vs green waste.

Mr^^

did you ever use lime as a buffering agent in your original mixes and if not did you substitute extra oyster shell or crab shell to buffer your soil from ph fluctuations?

 

[VortexPower420]

EJ is just over priced citric acid. You can get it in bulk of very very cheap and 1/8tsp will drop a 7 gal bucket to where I want it.

 

[HyDroid]

Bumping this because it solved some chronic problems that would occur within a single grow followed by plant life threatening problems when reusing soil.

I have high alkalinity (lots of carbonates) in my water and the pH is over 8.5 out of the tap. Now I use EM-1 or citric acid to lower the pH to 7 or just below. Plants are so much healthier, no chronic problems in my reused soil. Took a week or so to kick in for the reused soil, only took a couple of days to correct a new batch of soil with only 3 weeks of seedling growth. For the reused soil I pH'd to 6 initially to make up ground faster. New seeds didn't like 6 but thrived in 7 (no chronic issues like untreated tap water), old soil got back on track and now everybody does really well in pH 7 water.

I prefer organic acids over strong acids like phosphoric for their buffering abilities and because accumulating more P over time isn't good either.

I will also say for completion that watering frequency plays a role in how quickly and strongly the problem manifests but I believe that addressing this issue is fundamental. You can get lucky or temporarily solve the problem with the right lime balance in the soil but this is likely substrate, plant, and water source dependent. Better in my mind to remove the potential problem out the gate.

Rainwater, after all, doesn't come with substantial CaCO3.

I hope this helps somebody avoid chasing their tail as much as I did. I'm very happy that things are looking good at the moment.

The long term solution to this problem is to grow companion snails at a rate which offsets the irrigation CaCO3 inputs. #snailtech

 

[flylowgethigh]

interesting idea LAMBS - why do you think that would be better?

tbh i took more notice of the lime and pH stuff, need to read it again about the perlite/vermiculite thing

VG

I got to the synopsis and pulled this out:

" Mixes containing vermiculite settled more, had higher water holding capacity (WHC) and percent plant available water (%PAW), and similar air filled porosity (AFP), compared to mixes containing perlite. Dry mass was measured in corn, peas, tomatoes, and soybeans, and chlorophyll content was measured in corn. The addition of dolomite increased pH and decreased dry mass in corn, soybean, and tomato, but peas were unaffected. Chlorophyll content in corn also declined with increased amounts of dolomite. After a week of daily irrigation, pH 7.8 nutrient solution neutralized the acidity of the peat, without the need for addition of dolomite. Mixes containing vermiculite improved growth and chlorophyll concentration compared to mixes with perlite. The higher cation exchange capacity (CEC) of vermiculite-containing mixes may have improved nutrient availability.

I just found this interesting thread. This morning I added vermeculite to the soil mix for my run #2, for the CEC and added drainage to water the 10 gallon bags on the SWICK. Here is a thread I started that may have what I think is a way to measure the level of ionic exchange going on in our soils.

https://www.icmag.com/forum/marijua...il-ph-changing-during-a-run-real-mystery-here

 

[thailer]

Now I use EM-1 or citric acid to lower the pH to 7 or just below.

have you tried just using EM1 as a ph down? Seems like it would work similar to using vinegar? How well did it work long term if ya know? Most people I know with alkaline water are using the citric acid after chasing their tail for a long time.

nice bump

 

[VerdantGreen]

I got to the synopsis and pulled this out:

" Mixes containing vermiculite settled more, had higher water holding capacity (WHC) and percent plant available water (%PAW), and similar air filled porosity (AFP), compared to mixes containing perlite. Dry mass was measured in corn, peas, tomatoes, and soybeans, and chlorophyll content was measured in corn. The addition of dolomite increased pH and decreased dry mass in corn, soybean, and tomato, but peas were unaffected. Chlorophyll content in corn also declined with increased amounts of dolomite. After a week of daily irrigation, pH 7.8 nutrient solution neutralized the acidity of the peat, without the need for addition of dolomite. Mixes containing vermiculite improved growth and chlorophyll concentration compared to mixes with perlite. The higher cation exchange capacity (CEC) of vermiculite-containing mixes may have improved nutrient availability.

I just found this interesting thread. This morning I added vermeculite to the soil mix for my run #2, for the CEC and added drainage to water the 10 gallon bags on the SWICK. Here is a thread I started that may have what I think is a way to measure the level of ionic exchange going on in our soils.

https://www.icmag.com/forum/marijuan...l-mystery-here

yeah, the CEC is good, vermiculite will keep the soil wetter than perlite.. i use perlite 20% and calcined clay at 5-10%(which is Probably more similar to vermiculite). I'll be interested in how you get on.

VG

 

[HyDroid]

have you tried just using EM1 as a ph down? Seems like it would work similar to using vinegar? How well did it work long term if ya know? Most people I know with alkaline water are using the citric acid after chasing their tail for a long time.

nice bump

Thanks for the reply!

I've been using only EM-1 as my pH down and it seems to work great (ran out of citric acid a while ago). I worried about stability but I mixed a batch and left it for 24 hours and it read the same as when I mixed it, so I figure that it will be stable in the soil long enough. Not sure how it would work with hydro though.

My understanding is that EM-1 contains a number of organic acids, probably dominated by lactic and citric.

EDIT: Likely mostly lactic acid; the primary yeast doesn't seem to make citric, but I hear there are a lot of things in EM-1 so who knows.

I'd love to hear more about this if anyone has more insight, or a reason not to do it this way.