RO Water / Calmag with Soft Water Nutrients?

Just a quick one. I'm now using RO water. It's ppm is 35 and pH 7. I'm using Hesi soft water nutrients.

Now, in theory the nutrients should have everything I need (including the correct amounts of calcium and magnesium) and I shouldn't need to add anything.

However, I'm wondering if I should Calmag anyway, just incase? i.e. Bring my RO water up to 100-150ppm with Calmag before adding the nutes?

Any suggestions?

If your nutes are designed for soft water and you are using soft water, not sure I understand why you want to add more cal/mag unless plants are showing signs of needing it.

overthinking this

RO water with a pinch of calmag each watering is all

water softener not needed if RO and Ph'ed

good luck

Justin Freidman said:

Just a quick one. I'm now using RO water. It's ppm is 35 and pH 7. I'm using Hesi soft water nutrients.

Now, in theory the nutrients should have everything I need (including the correct amounts of calcium and magnesium) and I shouldn't need to add anything.

However, I'm wondering if I should Calmag anyway, just incase? i.e. Bring my RO water up to 100-150ppm with Calmag before adding the nutes?

Any suggestions?

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First off, ignore Vostok, as you can see. He doesn't even know what your talking about......

IT'S RO WATER. You always add back ca/mg at 5ml per gallon of water.....

Like Doc says, RO needs a supplement or it is rusty leaves all round and a Calcium deficiency in a late stage goes deformed and blackens the roots and the plant is good as dead for sure, although this is mostly the old blurple LED that done that to cause a Calcium issue .

In theory quality nutrients have enough Ca and Mg to work with RO water just fine and I never used CalMag for the first ten years of doing DWC without seeing any deficiencies. I did use a little epsom salts tho. With all the talk about CalMag I finally got some a few years back and use about 1/4 the recommended dose, just-in-case.

I still use some epsom salts later in flowering as the sulfur in it promotes trich development and we all want that.

Most calmag in water is not in its available form, carbonates are not the same as calmag. I do have a touch of calcium chloride in my analysis which i believe is plant available.

Really wish id paid more attention in chem classes now i grow weed

The Ca in most CalMag is derived from calcium nitrate which adds extra N that I don't want in later flowering. The GrowTek Cal-Max I got is 2%N which is half of what my Grow nutes are at 4%.

Think I'll make me some calcium sulfate and use good old epsom salts for the Mg. The extra S shouldn't be enough to cause problems like too much Ca can.

Some calmags are sulphates already i think.

OldMedUser said:

The Ca in most CalMag is derived from calcium nitrate which adds extra N that I don't want in later flowering. The GrowTek Cal-Max I got is 2%N which is half of what my Grow nutes are at 4%.

Think I'll make me some calcium sulfate and use good old epsom salts for the Mg. The extra S shouldn't be enough to cause problems like too much Ca can.

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The thing is really that the Mg will give problems faster then any S.. Sulfur is the magic elixir for cannabis

You should try K sulfate. I have yet to have any problem upping the K. Even to very high amounts in supplementing.
It's rather hard to overdose it on K sulfate.....Increases trich's and terps.....It also increases potency.
I run "high" K ratios in my soils and all through the run (other then seedling stages - once they actually go into my soils).

The other thing is that as a rule "most" nutrients, don't have enough Calcium for use in RO! Not to actually carry a cannabis plant - They have the same higher Ca needs as a tomato. Most marketed nutrients (even many that say so) aren't really formulated for cannabis. Fox farms is one of those - PERIOD.

For the use of buffering RO. I found years ago that using a Calcium carbonate over any Calcium Nitrate based formula. Is a far better choice for actually buffering RO.

I always liked G&H CALi MAGic....after I tried it as a new product years ago.

Great info Dr Who thanks for clearing that RO buffering as I was using the other method in the past with piss poor results now I know why.

i was asking myself also what to add to my Hesi (Coco)in regards for cal and mag.

But i can not tell how pure RO behave with Hesi (Coco), i use a 60:40 RO/Tap mix since a week, before Tap only.

So far it seems i prefer to mix it with Tap as otherwise there isnt enough buffer and Hesi plus pure RO give me a too low PH.
So i use Tap anyway as PH up,but would need more experiments for the best ratio, did you tried a mix and meassured the PH? (of course if ph+ is planned anyway, never mind)
This could point you in a direction, if you want to use pure RO, just that you take the PH in to account, you may allready did.

This isnt that easy for Hesi, as Hesi just list that they include "all" Calcium, Mgnesium,Sulfur and "others".
But never saw how much in percentage for any Hesi fertilizer so hard to tell if it is enough.
At least they made their mind about that, should be pretty complete, some fertilizer are missing some of the above listed elements.
Ratio of the elements also matters a lot, Hesi may did a good job there and it is all enough, but who knows, google didnt want to tell me.

And soil contains quite the handfull of cal and possibly mag carbonates, stuff builds up on all my drainage holes like a mofo.

OldMedUser said:

The Ca in most CalMag is derived from calcium nitrate which adds extra N that I don't want in later flowering. The GrowTek Cal-Max I got is 2%N which is half of what my Grow nutes are at 4%.

Think I'll make me some calcium sulfate and use good old epsom salts for the Mg. The extra S shouldn't be enough to cause problems like too much Ca can.

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That's very interesting about the extra nitrogen. I have plant magic cal-mag. The calcium is derived from calcium oxide. Does this product contain too much nitrogen for flowering?

http://www.plant-magic.co.uk/products/magne-cal-/7/

Interesting read.

I use CalMag with RO in Promix HP.

Mixed at 1ml/L I still seem to have a defeciency.

sleepless_canuck said:

Interesting read.

I use CalMag with RO in Promix HP.

Mixed at 1ml/L I still seem to have a defeciency.

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Its not cal/mag deficiency then...

Justin Freidman said:

That's very interesting about the extra nitrogen. I have plant magic cal-mag. The calcium is derived from calcium oxide. Does this product contain too much nitrogen for flowering?

http://www.plant-magic.co.uk/products/magne-cal-/7/

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I wouldn't want to use that in flowering. It has 8% N which is twice as high as the Grow bottle with the AN nutes I use and I'm pretty sure GH hydro nutes are the same at 4%N in the Grow.

The calcium oxide is just common quicklime. Same stuff they use to paint the lines for a baseball diamond in the grass.

During the first 2 - 3 weeks of flowering while the plants "stretch" they use a lot of N and need a full compliment of all nutrients to do their best. Extra P and K at this time is important for bud, (fruit), set. That can be added with just more of the Bloom or like many growers do bloom boosters. I've used Big Bud for over a decade as not only extra P and K it has 20 amino acids that supposedly enhance flowering. I like what I get so will keep using it.

After the stretch feeding drops off rapidly and after that excess N has an inhibiting effect on flower formation. Some is needed but not at the levels used during late veg or during the stretch. Look up "Lucas Formula" for more in-depth info.

OK perfect. I'll use it up until the stretch finishes. Thank you.,

Dr. Who said:

First off, ignore Vostok, as you can see. He doesn't even know what your talking about......

IT'S RO WATER. You always add back ca/mg at 5ml per gallon of water.....

Click to expand...

I have a soft water system and my plants been showing slight signs of cal mag deficiency at like 3 weeks old man, so I baught sum cal max 2-0-0 and gave 3.5ml per gallon .. it says to use 5ml per gallon though as u say... I believe my water runs like 90ppm after it’s softened .. what do I do I’m at day 31 on the bigger plants and I’m not sure if I should be buying 5 gallons of distilled for the next week to figure shit out or what I just wanna know whether I need to add the calmax at 5ml per gallon every single feeding or ??

canadiantoker420 said:

I have a soft water system and my plants been showing slight signs of cal mag deficiency at like 3 weeks old man, so I baught sum cal max 2-0-0 and gave 3.5ml per gallon .. it says to use 5ml per gallon though as u say... I believe my water runs like 90ppm after it’s softened .. what do I do I’m at day 31 on the bigger plants and I’m not sure if I should be buying 5 gallons of distilled for the next week to figure shit out or what I just wanna know whether I need to add the calmax at 5ml per gallon every single feeding or ??

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They sure look healthy enough but I wouldn't be using softened water as it adds sodium to the water and that's bad for the plants so maybe that's causing the issue. You could switch to using potassium chloride in your brine tank instead of the sodium chloride but remember not to use as much high K nutrients when feeding your plants as they will be getting some from the water.

When I bought this place the previous owner was already using the KCl in the softener but I decided I didn't need softened water so switched it to ByPass and it's been like that for the last 16 years. Water from my dugout was going in around 400ppm and coming out over 800. Used a lot of brine too so I don't think it was working properly anyway. Now it's just filtered down to 5micron before going to the taps and he had the filters in backwards with the 5 upstream of the 30micron one. lol