I’ve searched here and the web and cannot find a definitive answer. Im growing indoors in live soil. I have hard water, calcium 83.5mg/l magnesium 42mg/l ph 8.4
Im adjusting the ph with vinegar. My questions are, how much calcium and magnesium in my water is too much? Is there a definitive number? Will this sub for having to use calmag? Should I just ignore the hardness of my water and just stay the course, or do i need to remove the minerals?
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I don’t know the correct answer to this. I have very hard water and I just ignore it.
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What’s the TDS of your city water?
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Be careful with this. Some people have experienced issues using vinegar as a ph adjuster. Just a thought. I have hard water too. If you look up your municipalities water report you can find the numbers there.
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The TDS is 444
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That is about what mine is, mine might be a bit higher but not much.
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If you are soil growing I wouldn’t worry about it and likely do not need Cal Mag. If you are supplementing you may want to transition to R/O. The reason for this is all salts are additive and you have to account for the base water’s TDS when adding nutrients. This means that you can only had 500 to 600 ppm to your base water or you will burn plants. Using R/O you can use nutes for the entire TDS (target is 900 to 1,000 ppm).
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If you google you can find a calculator online where you enter your results and they will give an explanation. I am retired now but with your alkaline pH I would think the cal and mag are in carbonate/bicarbonate forms. You probably don’t need to supplement with cal/mag at those levels.
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With living soil I would send some out for testing after some run time to evaluate any accumulation, I do this every few months or so.
Calcium is used in very large amounts by cannabis plants and magnesium is a hard micro to cause toxicity, I believe you would be fine but testing is always a great tool to use!
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What about using peat moss to lower water ph?
I read where you can soak it in water overnight then strain. The water should be quite a bit lower in ph. Has anyone tried this or know about it?
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Pear moss is slow and gentle. It is not what you are looking for. I have used it for breeding Amazonian fish as ph down. Now days I use day old coffee as my favorite ph down. Or straight Coca-Cola.
Coke ph: 2.4
Pepsi ph: 2.5
Coffee ph: 4.5-5 depending on beans
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I didn’t know coffee would lower ph, thats good to know. My wife and I buy freshly roasted beans and grind our coffee each morning. Normally I throw that in a coffee can on the counter until it’s full, then take it out with the rest of my compost.
Now im thinking that it should go straight into a bucket of water and see what happens 
Unfortunately, the spent grounds are closer to neutral ph. All the tannins (acids) in coffee are water soluble and pass thru with the water. Spent grounds are more of a great fertilizer than an acidifier. But the left over beverage is up for the task.
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I mix spent coffee grounds in with my dry amendments when i add them… they tend to like coffee too! 
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Never thought of that. Lotsa sugar too. I use citric acid crystals if I need to lower pH. Just a pinch.
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Peat moss does have a low ph which is why I love it! You can load it will calcium to balance it out.
I guess the point I’m trying to get across is if you water with hard water with let’s say 50ppm magnesium and the plant only uses 35ppm between waterings after weeks, months, years, you will eventually build up an excess, yes peat would lower the ph but the more important part is what’s causing you to need to lower ph.
With living soil you don’t or shouldn’t water to runoff so nothing leaches out, what you put in is there to stay if not used by the plant.
Living organics is “easier” and less maintenance BUT it also requires a good bit of knowledge.
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Unfortunately it’s my only choice at the moment. Too expensive to buy as much water as i need. An RO system is in the future, but I’ve spent about as much as I can while keeping my wife from melting down
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It will work and definitely think you should use it,
Just be mindful you are adding 126ppm of cal/mag every single watering.
I’m only trying to explain the what’s and the whys of soil chemistry.
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Do you happen to have the rest of the data sheet I could take a look at?
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