Reliable ppm chart for marijuana??

CobKits

Well-Known Member
fwiw i had been using oakton tds meters for decades and finally got around to calling them to get a definitive answer on what factor they use. they say every oakton meter that has ever been is 0.5 scale. i couldnt find that published in any of their literature
 

bckushman

Member
I'm gonna add somethinh others seem not to have. Different brands of nutrients will have different appropriate ppms especially depending on what your using. I'm running seedlings at 700 right now BUT this is because I use an assload of beneficial microbes, and enzymes to prevent slime.(I run aeroponics) plus some sugar to feed to microbes.
With this I'm actually using less than 1/4 strength base nutes and 3/4 strength rapid start, and 1/8 strength cal mag(you always need at least a bit of cal mag if you use an RO system)

Also if you have a ro system remember to sterilize it regularly. Theres quite a bit of data proving virus's and bacteria build up in filters; in tests where people drank ro water vs. tap water more people drinking ro water ended up with nasty gastrointestinal diseases
 

Altered State

Well-Known Member
I use a Bluelab ppm Truncheon and it has all the different conversions on it: EC, CF, .5 ppm, and .7 ppm (Truncheon on the chart). Most people use the .7 conversion. It is the one on the left in the pic, was about ~$143 and worth every penny. It also has a five year warranty.
Hey Santos , Its my understanding the .05 scale is used in North America with the .07 used in the Eu ?
 

Beachwalker

Well-Known Member
I've been looking and looking but have not seen a reliable ppm chart for growing marijuana? I have heard people say use full strength, use half, use a quarter..I just want to know what you guys keep your ppm's at and when. If there is a nice chart somewhere out there that would be great too. Thanks! :)
I start them around 440ppm, heavy veg them 900-1100. Transition nutes at 1100 PPM, I run my normal flowering plants about 1100 and my heavy feeders about 1400PPM hope this helps, good luck!
 

Greez

Member
Hey Everyone!
I am using RO water, and it seems like my plants are yellowing from the center out. It is the top part of the plant, the new growth. I believe it is an Iron Deficiency. I add Cal-Mag Plus to my ro water, and use about 5 ml per gallon which makes it about 5-600 ppm. I just started an operation and am 6 weeks into vegging. I am using Growth Science organic line. 10ml each of grow, root magic, abundant-sea, and humic-tonic. The day after I gave them these nutes 2 of my plants started looking bad, now another is. While all the rest look great. So my question is, how do I correct this? Any pointers would be great.
 

OldMedUser

Well-Known Member
Hey Everyone!
I am using RO water, and it seems like my plants are yellowing from the center out. It is the top part of the plant, the new growth. I believe it is an Iron Deficiency. I add Cal-Mag Plus to my ro water, and use about 5 ml per gallon which makes it about 5-600 ppm. I just started an operation and am 6 weeks into vegging. I am using Growth Science organic line. 10ml each of grow, root magic, abundant-sea, and humic-tonic. The day after I gave them these nutes 2 of my plants started looking bad, now another is. While all the rest look great. So my question is, how do I correct this? Any pointers would be great.
Measure the height on your plants and check a day or two later and I'll bet they are growing fast and that's why the grow tips are yellow in the center. It can take a day or two for them to green up during rapid growth. That's a good thing and tells you they are happy.

If low iron they will stay yellow as they grow out and low iron is pretty rare in soil grows. Generally when micro-nutrient deficiencies are found it's due to the pH being too high and locking them out.

Looks like pretty good nutes and probably have plenty of iron even if not listed from the ingredients they use. None in Canada tho as I'm weaning myself off hydro nutes for some of my medical growing.

Iron.jpg


JorgeCervantesCannabisDeficiencyChart.jpg

:peace:
 

Greez

Member
Sweet! Thanks! I am not sure If I can post pictures cause I am such a new member; however, I would like to. So you can see what I am dealing with.
4.JPG This is actually another plant that started showing symptoms MUCH earlier. And has now developed what you see in the picture.

I cant take pictures of the plant that lead me to believe it was an Iron deficiency, because the lights are off. But the upper half of the plant was droopy, and the center of all the tips were a yellow tint with the veins green and the outside tissue yellowing. In the center, but the outside was normal. It was strange because the plant was perfect, than I went in and saw that the upper half of the plant was droopy.
 

OldMedUser

Well-Known Member
Got a bit of nute burn going on with that plant. Plants will go droopy at different times then stand up and pray to the light at others especially after a good watering. At least mine do.

Mine are lime-green in the centers too and up praying to the light right now. Got a good watering about 12 hours ago. Been having to raise the light at least an inch every day for the last week since repotting.



YellowCenters.jpg

I have 13 plants and 6 strains on the go atm. All under a 400W Philips CMH bulb. Nice white light so looks perfect with no white balance correction needed. Runs off a magnetic HPS ballast.

One of each Dutch Kush, Hindu Kush, Ayahuasca Purple and AK47 are all in bigger pots and going downstairs ASAP into even bigger pots and flipped in a couple weeks. The white pots are 4 - Island Sweet Skunk X DJ Short's Blueberry in 1L pots and 4 - Hi-CBD fem plants called Sebring's Revenge in 2L pots. And one Hindu Kush clone that's now as big as the others in another 1L pot. Not liking that one for growth traits but will see how it's mom is once flowered out before deciding to keep it or not. Want to start some more strains as well but don't want to get swamped. :)

YellowCenters2.jpg
 

Greez

Member
@OldMedUser

Nice! I suppose people are a lot more open to sharing these days. I started my operation about 6 months ago. I am growing for a handful of cancer patients. I used to grow when I was younger and was told I was pretty good at it.

This time I am using Reverse Osmosis water, which is throwing some serious wrench's in my gears cause I have to add Cal-Mag, and constantly adjust the PH.

I got my seeds from PacificSeedBank. I got ACDC, Cannatonic, Blue Dream, Girl Scout Cookie, White Widow, California Big Bud. I got in touch with Resin Seeds, the Breeders of Cannatonic in Amsterdam. They informed me that PacificSeedBank is not selling their seeds and sent a cease and desist. With that said I really have no clue what I have.

I got in touch with Growth Science yesterday and sent them pictures of my plants, and they told me it is likely a PH lockout issue I am having. I calibrated my PH pen and it was showing 6.8 in 7.0 calibration solution. So I re-calibrated it, and it is likely that the PH was too Acidic or Low. So they told me to flush with 7.2-7.5, and refeed with 6.2PH. I also did not adjust my PH after I mixed my nutes together, and they explained they had a very low PH to increase shelf life. Also catalizing to a nutrient lockout of Cal, Mag, and Iron.

I never had to deal with all this PH and PPM and adding Cal-mag to RO water. Its very time consuming, but after not growing for almost 10 years. I absolutely LOVE it. Every second I am with my plants is a second I realize I belong. Its quite spiritual. xD
 

OldMedUser

Well-Known Member
This time I am using Reverse Osmosis water, which is throwing some serious wrench's in my gears cause I have to add Cal-Mag, and constantly adjust the PH.
I hope you're not testing pH of the RO water and making adjustments to it before adding your nutes and CalMag.

RO and distilled water have no real pH of their own. They get their pH from whatever is added to them.

The hydro nutes I use are AN's pH Perfect nutes with RO so I never even think about the pH whether in DWC or soilless. The only time I check pH is if I'm adding silica to the water first and I use the AN Rhino Skin so don't really worry about it and just add 4 or drops of conc sulfuric acid after mixing in the silica then add my nutes.

I use CalMag at half the rate you do at 2.5ml/gal and only about half the time in DWC. The ProMix HP I'm using has lots of dolomitic and calcitic lime in it already so I use even less for plants growing in it. The first ten years I grew DWC I never used CalMag and never saw a calcium deficiency tho did seem to have low Mg at times and fixed that with Epsom salts.

A lot of growers here seem to think CalMag is some sort of magic bullet and advise people to use lots for every issue they may be having. It's not.

I'm pretty sure you don't have an iron deficiency. Just normal growth is all I see and new leaf growth needs exposure to light before it can turn green so when the plants are growing fast the newest growth looks yellowish until the chlorophyll gets active and greens up.

I've seen too many people mess up their grows tossing stuff at a perceived problem only to make it worse.

The forest fires here in northern Alberta have us socked in with smoke today. Visibility is down to about 300yds and I woke up thinking the house was on fire. Not even June yet so it's gonna be a hot and smokey summer for sure. :(

:peace:
 

guitarguy10

Well-Known Member

Attachments

Last edited:
I have been looking into nute levels etc over the last few days, and was given this link by another member on this forum, it talks about 'usable PPM's' rather than the ones you'll get from your actual reader.

For example, I am using the Botanicare KIND BLOOM, if I add 1ml to exactly 1 litre of RO water, my meter reads 332 uS/cm. However using the calculator in the link below, it suggests that there is only 246 uS/cm available to the plant. The reason being is that most liquid fertilizers use Phos P2 O5 - technically the plant only has access to 43.7% of what is on the label...

Another example..

KIND BLOOM
0.0% N
6.0% P
6.0% K

Actually translates to:

0.0% N
2.62% P
4.98% K

I have an extremely complicated spreadsheet, which I can share if anyone wants it. You'd just need to swap out the products and the analysis to tailor it for yourself. Can have up to 11 different products on it in its current form.

Link is here:

http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm

Annoyingly it keeps coming up with a Java pop up which I just close out, but it works pretty well.

Also a print screen of my PPMS based on 5 weeks of veg, 8 weeks of flower with a flush in the 9th week.

Screenshot 2019-08-18 at 02.14.37.png
 
I have been looking into nute levels etc over the last few days, and was given this link by another member on this forum, it talks about 'usable PPM's' rather than the ones you'll get from your actual reader.

For example, I am using the Botanicare KIND BLOOM, if I add 1ml to exactly 1 litre of RO water, my meter reads 332 uS/cm. However using the calculator in the link below, it suggests that there is only 246 uS/cm available to the plant. The reason being is that most liquid fertilizers use Phos P2 O5 - technically the plant only has access to 43.7% of what is on the label...

Another example..

KIND BLOOM
0.0% N
6.0% P
6.0% K

Actually translates to:

0.0% N
2.62% P
4.98% K

I have an extremely complicated spreadsheet, which I can share if anyone wants it. You'd just need to swap out the products and the analysis to tailor it for yourself. Can have up to 11 different products on it in its current form.

Link is here:

http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm

Annoyingly it keeps coming up with a Java pop up which I just close out, but it works pretty well.

Also a print screen of my PPMS based on 5 weeks of veg, 8 weeks of flower with a flush in the 9th week.

View attachment 4381027
Forgot to add, the plant can only use 83% of K20 - Potash
 
Top