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water Very high pH tap water (9.8pH) & irrigating raised beds

Water quality report from November 2012:
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This report lines up with what I saw during my hydroponic grow. I was getting about 9.3 pH at the tap according to my meter. Couldn't measure EC of plain tap water with my meter since it was below the cutoff level of my truncheon. In the past with hydro & container gardening I've always pH balanced my water which is fairly easy to manage on a small scale.

However, I do not have very much experience gardening in raised beds, only 2 good seasons under my belt. So far I haven't noticed a problem with nutrient imbalance due to pH but I was wondering if continually watering with such high pH water will cause problems in the long run? There really isn't a good way for me to pH balance the water I use on my raised bed due to location & size. The bed is in a community garden at work & there isn't really a good way for me to set up an irrigation system & thus am stuck watering straight out of the hose.

So basically I'm wondering if this will be of concern & if so is there anything I can do about it? Soil amendments to buffer pH perhaps? I'm going to test the pH of the garden soil before planting & again a couple times during the season to keep an eye on it.

Luckily where my container garden will be this year the tap water is much better, measuring right at 7.4.
 
I wish I knew the answer for you but I have no real idea but I wouldn't think that a pH that high will be good for the plants since some neutrients might be locked out. Couldn't you get a couple 5 gal buckets and fill them up off the hose then adjust the pH of the water??? It doesn't take much pH Down to get you in the 6-6.5 ball park.
 
damn dude, 9.6 is crazy way high.

your carbonate hardness is pretty low tho, so it would not take very much acid to bring it back down.

you might want to test out some soil mixes with this water. id use a bunch of UNTREATED peat... to bring the ph down alot then work from there with soil amendments like aluminum sulfate and or ammonium/ urea.

its hard to say how your soil effects the ph of the irrigated water without testing. some things like peat have reletivly high cation exchange capacities....these will tend to buffer the soil ph keeping it acidic for a long time. there are about a jillion grades of peat that have different cec's tho, its guess and check as far as i can tell.

the way i see it... you water is way high ... its going to trend upwards as carbonates concentrate in your raised beds. now you can pretty much leach the carbonates out by watering the beds untill you get heinous amounts of runoff, or start adding things that acidify soil, or mixing in more peat or other acid things. its hard to say how long it will take to trend upwards and get too high... hell your water might even change to a diff source at some point as surface water treatment plants come online. i think its all going to depend on how much CEC your beds have, more peat =more cec generally and = more buffering of ph.



theres volumes of info on soil ph, id dig deep and make sure to get it right before moving forward. its a common thing to deal with, so it shouldnt be hard to dig out some information.


fwiw, peat will need to accumulate cations before it will buffer against a ph raise.
 
There's test strips for soil-pH values. I'd recommend to buy some and test the pH (some time after watering). If the soil isn't able to bring it down to a reasonable level, add peat.

Also chose a pH-stable fertilizer (since you're experienced with hydroponics I guess you already had that idea yourself) - Adding nitrogen as NH4[sup]+[/sup] instead of NO3[sup]- [/sup]will prevent the pH from climbing.
 
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