At what point do you need Cal Mag?

Hi RIU!

I'm working with tap water with ~120ppm and was wondering if Cal Mag would be necessary. This would be for DWC by the way.

Tap seems clean enough already as my RO gives me ~50ppm.

Of course I'd add it if I started seeing weird leaf growths/yellowing but what about normally?

Thank!

I grow rdwc and dont add cal/mag. Theres plenty in most nute brands. Imo most cal/mag 'issues' are caused by lockout due to flucuating ph. Now soil and RO water is a different story

I start calmag as soon as I start nutes. That's usually 2 weeks from seed.

I only use it on certain genetics that show deficiency without it. Read your plants, give them what they want, not what nutrient companies and strangers on the internet tell you they want...

Good question! My tap water is around the 200 mark and have never added calmag. My plants have never suffered but just finished the one year mark so real nube. Kinda wondering if it would be beneficial re bigger yields as well.

Doobius1 said:

I grow rdwc and dont add cal/mag. Theres plenty in most nute brands. Imo most cal/mag 'issues' are caused by lockout due to flucuating ph. Now soil and RO water is a different story

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Hi Doob. I'm curious what you mean by soil and RO is a different story. The reason I ask is I'm wondering if there are common issues with using RO in soil? That's what I use and I wonder if I am having PH issues or need a calmag supplement. My soil PH is a little too high and my fan leaves have looked a bit washed out. I don't flush and I use mostly FFOF and organic nutes. Any suggestions are appreciated!

I use calmag in week 2-4 of flower with the strain I have. It always shows calmag def without it in the first weeks of flower. If I supplement in weeks 2-4 it seems to hold it over until week 8.

I use tap around 110ppm but still use 1/4 strength calmag in my recipes as a safety factor. With ro water it is very important to use calmag because you don't have that buffer amount that has been removed.

Im a hydro guy no soil expert so take this with a grain of salt. For straight watering of plants in soil, I would add 1/4 of tap water back to my RO water to bring the ppm up to around 125 like SS said. Straight RO will suck the life right out of your plant. like humans, plants need a steady source of micronutiants and RO has zero but generally tap water will have enough micronutriants to last between feedings. Not just cal/mag. Theres zinc, iron etc. Humans shouldnt drink straight RO water either imho.

Of course this depends on your tap water. Mine is over 400 ppm of disolved crap. I would never pour that garbage straight on a plant

There is nothing wrong with tap water in hydro...

Thanks Doob! Very interesting. I'll try that. I need to find out the ppm of my tapwater now.

Agreed, you'll run into more problems with RO'd water if you don't have your system and nutrients dialed in almost perfect.
I've been running a flood-n-drain for cpl yrs now and haven't had to use calmag once. If you have to add calmag, then you might wanna switch brands.

This is a good thread. So if you were going to use a calmag sup what brand do you guys recommend? Cmag+, Calimagic? Thanks.

If you watch your girls closely they will tell you when they need a fix. Most strains will show signs around that 6th week of veg all the way thru the 5-6th week of flower. You may not need it so by watching them you will understand the cycle better and given a dose when noticed will straighten her right up. Once you see signs I would implement cal/mag from that point on. I don't think brand name is a real issue as long as its compatible with your main line of nutes.... JAS

Marijuana is a cal mag monster.Always add it to everything.The theory dont give it to it if it dont need it..well..it needs it..and it needs it bad and yes it is part of getting your grow dialed down and maintaining the best health for your plant.
Another thing that will keep your plants in tip top perfect shape is azomite .It is a mined mineral with every known micro nute your plant could ever want.You will never had a deff of any kind using it.
Silica.This makes your plants stems strong able to hold more weight,also makes your plants more drought resistant. also keeps plant resistant to PM.
Humic and Fulvic Acids.These makes your roots soft and melts the nutes so the plant uptake of the nutes better.
One or Two drops a gallon of super thrive(Vit B) This if you want to think of it as a energy drink for your plant.
Carbs,Molasses ,ext.Made by about everyone take your pick.
Adds starch and carbs .Same as body builders increase carb intake to get BIGGER.
All this being explained, do you have to use all of this to get a nice plant? NO.
It is a good idea to use it if you want to keep your plant in max health to produce to the best of its potential.
I didnt even mention feeding.Almost all of these items are just considered more for the health of the plant and have what is needed to assist the nutes in bud production.
You ever have PM? Whats it worth to keep it from ever happening?
You ever miss a watering or have a pump failure? whats it worth to come back and have your plants still alive?
Whats it worth to NEVER have a micro problem again?
Whats it worth to increase your size quality and potency of your bud?
You know how many times i hear someone on here say..oh man.i had to leave town for whatever reason and come back and stupid brother in law didnt water the plants and they were all dead..or someone who had a pump failure comes back in the next morning all all of his shit was dead.
How about the ten million questions from people on here..whats this ..whats that deff..all of that shit can be solved with some micros or azomite.Azomite cost like 40 bucks for a 40 lb bag and it will last like 200 years.
Walking on on your plants them 6 weeks into flower and every thing dead.WOW..you just wasted at least 2.5 to 3.5 months and the money you invested.You talk about heart breaking.Almost as bad as a male plant popping nut all over your bitch's when you aint looking.
Or spider mites.WOW..i really hate those cock suckers.
If your shit is good and healthy..when a problem happens..and it will. you will see it faster and be able to correct it faster when you know ALL other variables are covered.
I hope this opinion helps.