Tap water as temporary cal mag? baby jesus help my plant

So i ordered some cal mag about two weeks ago and it was from michigan and i was ok with waiting a few days becauseb at the time i didnt really need it but now i really do need some asap and the just had a pretty heavy storm so its been delayedb and i dont have funds for it at the moment to go out and buy some at the store so i was thinking about adding some tap water to my nutrient solution. What do you growers think? Itll be just a temporary thing

probably create more problems than it solves. You're assuming the tap water has available calcium and magnesium but without a water quality test it's impossible to say.

Your locality is required to publish an annual water quality report. It's probably on their web site. That should tell you a lot. If the ppms are around 200, I'd say it's ok to use it. If you're not doing organic, the chlorine content shouldn't hurt much. If it's higher than 200, you could cut it with reverse osmosis water to get 100-200 ppm.

az2000 said:

Your locality is required to publish an annual water quality report. It's probably on their web site. That should tell you a lot. If the ppms are around 200, I'd say it's ok to use it. If you're not doing organic, the chlorine content shouldn't hurt much. If it's higher than 200, you could cut it with reverse osmosis water to get 100-200 ppm.

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You got it right on the nail my friend thank you that was the perfect answer i was just going to check the ppm of the tap water when i got home but itd be more useful to research calis water report. Thanks much appreciated dude.

You can use epsom salt to add Mg to the water. There's no easy source of Ca though. You can dissolve eggshells in vinegar to break down calcium carbonate to pure(?) Ca. That takes 2-3 weeks. Then a week or two to let it evaporate, leaving you with Ca in powder form. If you had some of that on hand, you could add it to your water. Then you'd just be lacking the trace minerals which are probably present in your nutrients. (I.e., seems like Ca & Mg are the two which people need to replace the most when using RO water.).

az2000 said:

You can use epsom salt to add Mg to the water. There's no easy source of Ca though. You can dissolve eggshells in vinegar to break down calcium carbonate to pure(?) Ca. That takes 2-3 weeks. Then a week or two to let it evaporate, leaving you with Ca in powder form. If you had some of that on hand, you could add it to your water. Then you'd just be lacking the trace minerals which are probably present in your nutrients. (I.e., seems like Ca & Mg are the two which people need to replace the most when using RO water.).

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Damn i might try that with another plant that just popped, im trying to do organic as much as possible. But i found a chart and it seemed like the one i was looking for. What do you think on it? Should i go for it and do half tap and half distilled?

That looks good. 50/50 is probably ok. Maybe 100% tap. What is the total ppm of the tap? (I couldn't figure that out from the chart.).

az2000 said:

That looks good. 50/50 is probably ok. Maybe 100% tap. What is the total ppm of the tap? (I couldn't figure that out from the chart.).

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im not sure what the ppm is but i just checked on my package and its finally arrived! Im so stoked to get home and feed the lady! Im curios to try the water though on a different for test

My tap water is so hard, you can almost walk on it. RO I had the expected issues. I added tap water (about 10% of the res) and the issues went away and no need for expensive calmag. My hard water tap will increase the PPMs so I add enough tap to add an additional 60-100 PPM.

Most municipal tap water is just fine for MJ and honestly my tap water turned out to be better for me than the expensive ass RO water, no joke..

You can use calcium sulfate to supplement calcium. It's also known as "gypsum" and "plaster of paris" and you can make it from epsom salts and calcium chloride (a.k.a. damp-rid or ice melting road salts.) All readily available stuff if you don't have it already.

Observe & Report said:

You can use calcium sulfate to supplement calcium. It's also known as "gypsum" and "plaster of paris" and you can make it from epsom salts and calcium chloride (a.k.a. damp-rid or ice melting road salts.) All readily available stuff if you don't have it already.

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What is the process of releasing the Ca from the sulfur?

What I mean is, calcium carbonate is a common source of calcium but it's not readily available to the plant because acid(?) has to break the bond between calcium and carbon. I understood this to be a slow process. How does calcium sulfate compare?

When you dissolve CaSO4 in water it produces free calcium and sulfate ions. http://www.gypsoil.com/what-is-gypsoil/how-it-works

calcium sulphate is virtually insoluble in water, the best you`ll do is suspend it in water which isnt much good to plants Go to the local nursery/garden centre and pick up some calcium nitrate, dirt cheap highly soluble and the main ingredient in most Calmag bottles.

fish a handful of pennies out of a fountain somewhere and go buy a small bottle of cal-mag. it's not expensive.

Atomizer said:

calcium sulphate is virtually insoluble in water.

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Wikipedia says "Gypsum is moderately water-soluble (~2.0–2.5 g/l at 25°C)." A dose of Botanicare CalMag+ has 0.128g Ca.[1] It sounds like there would be plenty. Some growers say our plants love sulfur, makes dank buds, etc. (But then I wonder why we advocates of molasses emphasize "unsulfured.").

I'm just concerned about adding things I don't need. I like dissolved eggshell because, as far as I can tell, it's pure calcium. If I want to add sulfur, I'd rather amend that into the soil. (But, it's worth trying gypsum. My concern was that it would be slow acting like calcium carbonate is.).

[1] 3.8ml/gal is 4g by weight. It contains 3.2% Ca.

lushgreen said:

fish a handful of pennies out of a fountain somewhere and go buy a small bottle of cal-mag. it's not expensive.

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For the OP's purpose, that's true. But, for a deficiency I like to have pure Ca. (Gypsum might be ok.). I also don't like adding N via calmag. If my NPK ratios are dialed in, then I don't like to have a variable N through a supplment like calmag. If I add more dolomite to my soil (reducing the need for calmag with each feeding), then I have to rebalance my nutrients to get back to the NPK ratio that works.

Calcium nitrate (the "cal" in calmag) sounds more appropriate for hydro. I'm doubting my use of calmag to replace RO minerals. I'm thinking I just need to mix 1:2 - 1:3 tap to RO to get 100-200 ppm starting water (my tap water is high ppm). Then use epsom salt and dissolved eggshell (or gypsum) to treat deficiencies. Increase dolomite to reduce the occurrence of deficiencies.

Did a test today. After 8 hours of hydration:

If it's true that Gypsum will only go to 2g/L, that would be 370ppm max.

I don't believe dissolved eggshell has a g/L limit (within reason). I think it's possible to dissolve 10g (or more) to get 3700ppm which could then be used as a concentrate to treat RO water (along with epsom salt). Not sure this would be possible with Gypsum.

But, definitely, Gypsum's more readily available for unplanned problems. Dissolved eggshell takes a month.

When you dissolve eggshell / CaCO3 with vinegar (acetic acid) you get calcium acetate. https://en.wikipedia.org/wiki/Calcium_acetate You can make a concentrated stock solution from it unlike gypsum. I know calcium acetate is the main component of "one part" calcium additives for reef tanks which you can get at an aquarium shop but it might have other undesirable stuff in it like calcium chloride.

432g of yara calcium nitrate in a 1 liter bottle is how much I use in my 2M stock solution of calcium nitrate. (yara is the double salt 5Ca(NO3) + 1NH4NO3)

Anyway, my point is you can dissolve a shit ton of calcium nitrate in water. That's what I've been saying! Dry salts fill almost half the bottle before filling the rest with 0ppm water, and it comes out crystal clear, as if it was pure water.

Calcium chloride is the only other highly soluble calcium salt, but like observe & report said, it's undesirable because of the chlorides. That leaves you with only one reasonable option if you want soluble calcium.

Save your money on calmag+ and just buy 1-5 pounds of calcium nitrate. It's dirt cheap from most greenhouse stores.

az2000 said:

Did a test today. After 8 hours of hydration:

Gypsum: 1g/L
PPM: 185

A lot of undissolved material on the bottom. Water looks milky. May not be dissolved but in suspension. I think it would need to be strained so chunks don't sit on top of the soil continuing to contribute when it's not needed.

Dissolved eggshell: 1g/L
PPM: 505

Virtually completely dissolved. I see a few tiny flecks swirling around when I shake it.

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If it's true that Gypsum will only go to 2g/L, that would be 370ppm max.

I don't believe dissolved eggshell has a g/L limit (within reason). I think it's possible to dissolve 10g (or more) to get 3700ppm which could then be used as a concentrate to treat RO water (along with epsom salt). Not sure this would be possible with Gypsum.

But, definitely, Gypsum's more readily available for unplanned problems. Dissolved eggshell takes a month.

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Observe & Report said:

When you dissolve eggshell / CaCO3 with vinegar (acetic acid) you get calcium acetate. https://en.wikipedia.org/wiki/Calcium_acetate You can make a concentrated stock solution from it unlike gypsum.

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After 3 weeks dissolving eggshells the solution is ph 5.4. I used that a couple times but didn't like how I needed more ph up. I left a bowl out for it to evaporate. Crushed up the remaining crystals into a powder. (Wasn't hard to do. It's kind of like Rice Crispies.). When I added 1g of that powder to 1 liter water it didn't change the ph. I assume it's as available for uptake as when it was in vinegar. It dissolves in a few minutes.