Water, hard water. water

Hello folks. I have not started anything yet.(waiting for seeds) I have a dug well the water is hard. will this water be ok to use for growing?.Not sure of the ph yet.I do drink it other people do not like the taste. I have used it in fish tanks. Thank you for your help.

You could have it tested. I think big box hardware stores sell reasonably priced at home water test kits.

You could buy a TDS meter, if you’re into that sort of silliness.

Or you could try growing one when your beans arrive and find out first hand. :man_shrugging:


You’ll need a pH meter and and TDS meter for your grow, so I would get them now and check the water. Carbon filters will remove off odors and off flavors. If it is too hard you can cut it with RO (reverse osmosis) water. Those water machines at grocery stores are RO water and is fairly cheap (like 35 cents per gallon or even less if you get 5 gallons at a time). Or you could just buy a home RO filter that has a small storage tank that goes under the sink. But RO takes time (it is a slow process) so you might have to plan ahead for larger amounts of water if you buy an RO filter (which is really several filters in series).

You will also need pH up and pH down solutions.

There is a company called Ward Labs that will test your water and tell you exactly what you have. You schedule it, they send you the kit, you mail the sample back and they send you the results. It was about $35 but may have gone up, it’s been a while since I used them.


In most cases you’ll need to adjust ph regardless, and tds tester is nearly worth its weight in gold for new grower. That stuff will tell you just about everything you need to know about your water.


@lumpster1961 I have well water too. It’s moderately hard water and my ppm (as measured by a TDS meter) and pH is about 180ppm and 8, respectively. It’s drinkable water. The good part of having water like this is that is it has minerals like calcium, so I have never had to add cal-mag to my water. Get the TDS meter and check your water, you may be good to go already.

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If it’s safe for humans, it’s probably fine for plants. Just get a digital pH meter on Amazon (less than $20) and ALWAYS check and adjust the pH. Well water is sure to have enough calcium and magnesium. Only rain water or RO water needs Calmag. You want pH 6.5 for soil and 5.8 for hydro or coco coir. You can use common vinegar to adjust pH down.


Really? Source??

Again…false. The sith deal in absolutes… beware

Yep…it’ll lower your pH. And destroy any soil life.

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Easy to find out if your water is safe for plants: Do you actually have any plants you water with your domestic tap water? Do they die? Anybody have domestic water that kills plants? …crickets…

Well water by definition is in contact with minerals in the ground. Calcium and magnesium are incredibly common on Earth. Therefore, well water contains calcium and magnesium. Anybody have well water that does not? …again crickets…

Rain and RO water: You are correct. I did not mention distilled water, which is pretty much identical to RO. My source is basic knowledge of chemistry.

Vinegar Source: BS in Biology, and I have always used vinegar to lower pH and I have grown some fine crops. It’s totally an organic substance and you only need about 1 teaspoon per gallon to lower pH. At much higher concentrations it does hurt plants, but at the concentration needed to adjust pH it probably has a beneficial effect because it kills root rot fungus. When added to water or nutrient solution to adjust the pH as low as 5.8 essentially all of the acetic acid will be disassociated into H+ and acetate ions. The H+ concentration would be the same as with any other acid used to adjust the pH. (That is the definition of pH.) Acetate concentration would be the same as dissolving Calcium Acetate in molar equivalent amounts, and Calcium Acetate is registered for use in several fertilizers.

Didn’t give anyone much of a chance…

So the goal here is just not to kill them? Got it. Absurd.

It’s fuzzy logic, but I can grant that. How much calcium? how much magnesium? enough not to need any more? Still need to add a little? Way too much??? Back to my point of needed a water test of some sort if you want to know for sure.

At least we’ve got two letters we agree on. Let’s not start throwing out who has what letters after their name. You won’t win, and it no accredidation can help in growing optimal plants. But I sure as hell don’t want to be the one telling new growers to use vinegar on their plants. [quote=“1BigFella, post:8, topic:27049”]
because it kills root rot fungus.

You honestly believe that acetic acid is SELECTIVE is killing only the harmful root rot fungi? I can hear the beneficial fungal hyphae (that have symbiotically paired with your plant roots to bring them nutrients in exchange for root exudates) screaming every time you use it on the soil. Of course, that also goes for most “fertilizers”. Let’s not start in on Monsanto.

or magnesium acetate (what’s that do?) or iron (III) acetate (how about that?) or potassium acetate (crickets???)

You do you, man. Just try not to ruin anyone else’s grow for them. I cannot stand unfounded stoner “science”. You should own a hyrdo shop.

People make this a lot more complicated than it needs to be. Perhaps to sell more products to the growers. Perhaps to inflate their egos. I don’t really know or care. I know what has worked for me. I actually know quite a lot about water quality because I’m an old Southern California avocado grower and have had to use water that is sometimes to hard for avocados (until my water district started desalinating). My comments about calcium and magnesium in domestic water supplies is well known if you bother to look up information about Cal-Mag.

I don’t think acetic acid is selective, but I do think in the quantities I am suggesting it will have little effect. That’s because of direct experience: I once “watered” my mother plant with straight 5% acetic acid by picking up the wrong bottle. I realized my mistake and immediately flushed it with a couple of gallons of water and the plants was fine. So much for the “vinegar is toxic” theory.

I think optimal is the enemy of good enough: I have read many more posts about newbies killing their plants by doing too much than not doing enough. Enough light, a good cannabis veg fertilizer, a good cannabis bloom fertilizer, pHed solutions, and decent water is all you need to grow great weed. This is a weed, after all. You can likely spend a lot of money and make it 5% better. Or you can just relax, not get obsessed about it, and smoke 5% more.


Don’t forget arsenic and radon. I get that in my well water too. Mmmm arsenic and radon. I appreciate the invention of filters.

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If it wasn’t toxic, why’d you flush it?

If your well water is harmful for humans to drink without treatment, I would certainly treat it and test the resulting water, just to be sure I was not drinking poison! Wells that are not fit for human consumption are the exception that proves the rule. Almost every supply of domestic water that people can drink is okay for plants. When people try to over-manage their water by using only RO or distilled water, they have to add a lot of stuff or the plants can get obscure deficiencies. They create a problem where there was none to begin with. Instead of switching to RO water and having to add in precise ranges of 17 different nutrients, I would just use half tap water and half RO if my tap water was too salty, and then add a commercial cannabis fertilizer. That is precisely what some avocado growers have been doing for years. Most water districts publish a yearly water quality report which is free! No need to pay for one if you have that.

If it wasn’t toxic, why’d you flush it?
Mostly because it’s pH was down below 4. And if you have all those degrees you should know very well that almost everything has a dose response curve. Water is good for you, but drink too much and you could die. A little salt is fine, too much and you die. etc. Dimethyl fumarate is a banned anti-fungal that can kill you, but in moderate doses it prevents MS attacks. I saturated the pot with 5% acetic acid. I meant to use 1/750th that concentration.

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We test annually and have a filtration system to take out the nasties. Here in the northeast trace arsenic and radon come with the earth here. It’s shocking though when you do a home inspection and find out something like arsenic is present. But that’s why we do home inspections in the first place, and then make the prior owner pay for the filtration system.

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My well water is over 2500 ppm and ph of 14
State says anything over 500 ppm is bad for you…
I have $3500 dollars worth of filtration that brings it down to 285 ppm and ph of 8 but I only use it to shower and flush toilets…
Plant and drinking water comes from a health store with a ppm of 0 and a ph of 6.5 for 20 cent’s a gallon…
Now that I might be buying the house I will be looking into more filtration… :thinking:


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pH 14! Jesus Christ, that’s not water, that’s lye solution. Even PPM 500 is not a sure thing from that well. What if it’s 500 parts per million of arsenic? You really should install an RO system taking it’s input from your existing filters. The health food store is selling you RO water at that PPM 0 and price. You might not save any money, but you can haul less water.

Then you need to create water with all the trace and major elements. Most commercial weed fertilizer makers don’t add Calcium or Magnesium because almost everybody gets enough in their water. So you will probably have to add it yourself. Ask your fertilizer maker.

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Ya , are area has a class action lawsuit going right now , kinda like the Aaron brockavitch movie… water is no good… but dont really have a choice … I just filter the crap out of it and hope for the best… I will be having my water tested here in a few weeks… I’ll let you know what I find out… :wink:


Are you all suing some mines or something like that? Hard to sue for something no company or person caused. I’d be really interested in the results of your water test. Kind of problematic though because it’s only as good as your filters. As they go bad, the water they produce will get worse. So you really have to maintain them. A cheap dissolved solids water tester would be a good investment so you can tell when to change filters.

Ya , I grow hydro rdwc … I have lots of water checking equipment… :wink:
And the lawsuit has to do with an electric company in my area… at some point what ever they were doing wasn’t being monitored and some how polluted the crap out of the water underground where we live… :wink:
They knew what they were doing was hurting the environment , but continued to do it until someone in the company blew the whistle… :wink:
I’ll probably be dead when it gets settled , but the money will go to the kids when and if that day comes… :wink:


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Great Thread! I had issues on my last 2 grows, and water seems to be a prime culprit. I based how I amended my water using Jellas test strips, but bit the bullet and bought a APERA pH tester,and TDS meter. The same water tested 7.1 (strips), and 8.3 using the meter. I also know I’ve got 317ppm in my well water.
One question, does pH down effect the calcium in well water, or any other minerals which may be present ?