when to use calmag?

caper40

Active Member
just wondering when to start using cal mag my seedlings are now 2 weeks old and i am thinking about feeding them in a few days as i have repotted them today and am gonna let them them settle in their new home
 

moondance

Well-Known Member
Hi how are you? I am sorry I didn't not see your post till this morning! At this stage I would use a baby food mix for them, kelp juice is fine too. So I am assuming your into a 1 gallon pot now - correct. I would wait for 2 more nodes to grow out till I gave them Cal-Mag at say 2ml with feeding, and increase as time goes on, I don't any more than 10ml by the end of flower. Keep us up dated on the grow, and the following smoke report - we freakin love the smoke reports around here! Thanks for Growing! Peace, be safe MD.
 

Chorse

Well-Known Member
Adding CaMg is not a necessity in all grows. It depends on on your soil and water. What is your medium and what is your water source? I personally have not needed additional Ca but discovered I did need Mg. It was discovered on my first couple grows years ago and now I know to start adding Mg (Epson salt) late in Veg to the point I switch to plain water at the end of flower. I also only add the epson at a rate of just less than 1/4 tsp per gallon.
 

jwreck

Well-Known Member
Calcium is usually the first deficiency to show up for me, im in soil and use plain tap water and my seedlings still get those copper patches around day 9 so i have started adding 3-5ml a gallon from the starts and the seedlings the last 2 grows have been doing great and no brown copper spots or necrosis in any part of the seedlings
 

Chorse

Well-Known Member
Calcium is usually the first deficiency to show up for me, im in soil and use plain tap water and my seedlings still get those copper patches around day 9 so i have started adding 3-5ml a gallon from the starts and the seedlings the last 2 grows have been doing great and no brown copper spots or necrosis in any part of the seedlings
is your water softened?
 

jwreck

Well-Known Member
All i know is that its city water, i onced used a ppm meter and it was like .40 or something and the ph was 6.9 i dont even use ph meters anymore since the recommended nutes only drop my ph to 6.4
I guess im just lucky but calmag shouldnt hurt the seedlings atleast a 2-3ml a gallon shouldn't
 

moondance

Well-Known Member
I would give them 1ml, wait 3 days and see if they want more, like a week from now you can give them 5ml no problems. Thanks for Growing! Peace, be safe MD. I have city water myself and they add all kinds of shit to it, mine sits for a week before using it just to try and dissipate the bad.
 

Roger A. Shrubber

Well-Known Member
I would give them 1ml, wait 3 days and see if they want more, like a week from now you can give them 5ml no problems. Thanks for Growing! Peace, be safe MD. I have city water myself and they add all kinds of shit to it, mine sits for a week before using it just to try and dissipate the bad.
chlorine will dissipate overnight, chloramine takes 2 to 3 days, if you let it sit longer than that, you're raising the ppm of things that won't evaporate while the water does.
 

moondance

Well-Known Member
chlorine will dissipate overnight, chloramine takes 2 to 3 days, if you let it sit longer than that, you're raising the ppm of things that won't evaporate while the water does.
Good to know, I actually have never checked the ppm here, I have always just let it sit for a week or more before using it, and then throw a air line in for a few minuted before adding nutes. I may pick on of those up just to see what it is at because you have me curious now. Thanks for Growing! Peace, be safe MD.
 

caper40

Active Member
thanks for the replies guys and gals gonna wait and see how they rebound im only using tap water right now from now on will let the water settle for 24 hours before using it though
 

OldMedUser

Well-Known Member
chlorine will dissipate overnight, chloramine takes 2 to 3 days, if you let it sit longer than that, you're raising the ppm of things that won't evaporate while the water does.
Chloramine doesn't dissipate no matter how long you let it sit. Most tap water is crap for your plants so I never use it. RO from day one!

People that do should contact their town or water supplier and get a water analysis report to know what's really in their water. Often very high sodium and other things you don't want to feed your plants. Or yourself for that matter. Shouldn't cost you nothing for the info and it might just save you a lot of grief down the road.

:peace:
 

Roger A. Shrubber

Well-Known Member
you don't actually have to let chlorine or chloramine gas out, thats really more for fish than plants. neither one is good for your plants in high doses. chlorine IS good for your plants in low doses, and chloramine is harmless in the amounts that go into water treatment. the real problem with either is they're bad for your benes if you're using them. if you aren't adding benefical mocrobes, makes no difference to your plants.

far as ro, its ok, but you need to add cal mag to it for most uses, unless you're in amended soil or very charged coco. my tap water is 25 to 30 ppm 6 days a week, mondays they do w/e they're doing and it might jump to 80-100 for a day. not saying thats usual, but thats the way it is here, so no need for ro water where i am
 

OldMedUser

Well-Known Member
You're a lucky man Roger to have such nice water out of your tap. Most don't and many I've seen and informed on various forums have tap water that test at 400+ ppm and has lots of other nasty crap in it. I usually tell them to get a water report and post it so I can decipher the results for them. Diploma in environmental chem helps with that.

Chloride is good for your plants in low doses. Chlorine not so much. Apples and oranges there.

For sure a little CalMag is good with RO water or coco as a medium but if you use quality nutes like I do I never noticed any deficiencies in either in 10 years of DWC growing tho I did add small amounts of epsom salts regularly.

Most people use the max on the bottle label and that's more than needed. With most tap water there is more than enough Mg and Ca so adding more is overkill that can lock out other nutrients.

Mg deficiency is pretty easy to spot even tho it mimics low N as both are mobile nutrients so if either is low the older leaves give them up to feed the newer growth. Ca on the other hand is immobile so the older leaves aren't affected until it become chronic and the first signs are in newer growth.

Slow growth and young leaves turn very dark green.
New growing shoots discolor.
New shoots distort, shrivel and die.
Bud development slows dramatically.

Ca also gets washed out with regular foliar feeding or spraying with plain water. Don't know why people do that unless it's for bug treatment or an attempt to get Mg etc fast into a plant that has root problems.

Don't spray your plants folks as they don't need it! I don't even spray cuttings when I'm getting some clones. Just spray the inside of the dome to keep the RH as high as possible.

:peace:
 
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