High UB!Dave, just posted the same thing about Brita in CountryFarmer's thread. A point reduction is about right especially if high in bi-carbs. Brita filtered water would be perfect regarding his well water.
What I do before planting to drop the soil's pH:
1. Add quite a bit of peat moss,
2. Add granulated sulfur (pastules).
After planting:
1. Add/scratch in peat moss,
2. Add/scratch in about a Tblsp. of powdered sulfur to a 3-5 gallon pot,
3. Use acid foods like azalea, 21-7-7,
4. Use sulfate type salts - ammonium sulfate, iron sulfate, and finally,
5. Don't worry about it unless you can directly attribute some deficiency or imbalance to pH. Cannabis is very pH tolerant contrary to forum "popular' thought.
Run the tests - pH adjusted water does little to adjust the soil's pH on a long term basis. Soil is a powerful buffer.
If you must - an inorganic acid like sulfuric, phosphoric, or nitric is much more stable (effective) than an organic acid like citric. Adding it may (temporarily) change the top 1" or so but what have you got at the bottom of the pot where the majority of your feeder roots are located? A cheap source of sulfuric is battery acid from an auto parts store.
UB
The soil I'm using was mixed up at my last grow location, where the TA wasn't this high. We tested the well water, and everything was OK....but it changed, got a lot harder.
The soil had some lime mixed in, and combined with the very hard water, I was worried.
I really appreciate your comments on sulfur.....I've got some. Shall I go ahead and put a tbsp in each pot? They are 3 gallon pots.
I have the ability to mix with RO without too much trouble....but I really miss being able to crack the hose bib and water with the wand.
The plants are superbly healthy at this time....but I did see signs of stress when using untreated well water. What with the gypsum, epsom salt and lime added to the soil, I think there was just too much.
The new soil has no lime and is peat based....with a good amount of poop. Should be able to handle to water.