SativaSumo
Well-Known Member
I'm using a Bluelabs EC pen along with GH's Flora series. My question is that I need to know what my target EC should be. How do I determine that?
Help with EC meter
- Thread starter SativaSumo
- Start date
Pinworm
Well-Known Member
SativaSumo
Well-Known Member
Let me ask a different way.... OK, so GH's feeding page (here) lists measurements in .ml and how much of each you should give to the plants at what stage. Am I supposed to be converting that into an EC reading somehow? Or do I continue to dose based on those tables.
Follow-on, if later in the week I find my EC has dropped, how am I supposed to know how much of what to add back in?? Or am I supposed to DTW and replace my rez?
Follow-on, if later in the week I find my EC has dropped, how am I supposed to know how much of what to add back in?? Or am I supposed to DTW and replace my rez?
SativaSumo
Well-Known Member
Yup, first thing the pen touched was cal solution.
nomofatum
Well-Known Member
1200 PPM is the approximate sweet spot for most of my plants. If I run 800 PPM they just drink more and pump more humidity into the air to get the same amount of nutes. So I can run 800 PPM or 1200 PPM with identical results, but I will have to top off the system more often at 800. At 800 PPM in mid-flower I've had a plant drink 5 full gallons in less than 36 hours.
SativaSumo
Well-Known Member
So my final EC after I was done refreshing my rez today was 1200. So later in the week I need to get it back to that same level, yes?
nomofatum
Well-Known Member
It won't hurt the plant to jump back down to 800 or to jump up to 1200 from 800. A decent rainfall would do something similar to plants outdoors in soil, the extra water dilutes the nutes and PPM drops. Or the opposite, they get fertilized (pee, poop, or chemical.)
They will adjust how much they consume to compensate.
Just keep it under the point where the plant begins to burn and you will be fine.
SativaSumo
Well-Known Member
Right. So I get feedback from the PLANT on how much is too much... so what exactly does the EC pen do for me???
THE KONASSURE
Well-Known Member
starting out is like 100 to 400ppm
mid veg 300 to 600ppm
end of veg 600 to 1000ppm
flower 1000 to 2000ppm some strains can take up to 3000ppm but not much need to push over 2200ppm most of the time
gotta get to know your set up and the strain your running and keep on top of your ph
Also remember to get a base reading off the water before you start some people take the whole number off some people like to assume half of the ppm`s in your "empty" water is nutes so only subtract half
mid veg 300 to 600ppm
end of veg 600 to 1000ppm
flower 1000 to 2000ppm some strains can take up to 3000ppm but not much need to push over 2200ppm most of the time
gotta get to know your set up and the strain your running and keep on top of your ph
Also remember to get a base reading off the water before you start some people take the whole number off some people like to assume half of the ppm`s in your "empty" water is nutes so only subtract half
nomofatum
Well-Known Member
It's clear we aren't all using the same nutes and starting water PPM. 2000 PPM will kill some strains I've grown, but will burn most of them, even in the hungriest part of flower. When you increase your PPM, just do so in increments of 200 PPM or less so if it starts to burn it will be very minor and you can back off the PPM by diluting.
Resinhound
Well-Known Member
This is kinda one of the reasons we are all here learning to grow this plant.Start with one quarter to half of the recommended dose.Measure the ec,watch your plant,reasearch and learn before next feeding so you can apply what youve learned.
ttystikk
Well-Known Member
It's your growing style. Mine love EC 2.0 because they're under 860W CDM lighting and I keep my RH much higher than most, closer to 70% and low 80s F, this to help optimize VPD and CO2 uptake.
There is a conversion chart here.
That's an interesting question: what are the ppms published by GH? There are different TDS "scales" for meters. But, when you calculate ppms from the weight of chemical compounds.... what does that relate to? I think it's 0.5 scale. For example, 1g of table salt dissolved in 1 liter of distilled water = 1000ppm (by calculation.).
FWIW: I used GH Flora 3-part with the so-called Useless schedule. That worked really well. He seems to have the strength right at the edge of what you can run. People usually run 1/2 GH's label. He does about 2/3 to 3/4.
FWW, this is what you get using GH Flora 3-part at full strength:
--------------- R A T I O S
---------------- N-P-K ---------- K-Mg-Ca ------- PPM
Seedlings -- 1.21-1.00-1.82 -- 5.48-1.00-2.67 --- 126
Mild veg --- 1.21-1.00-1.82 -- 5.48-1.00-2.67 --- 503
Aggr veg --- 2.07-1.00-2.98 -- 7.98-1.00-3.57 --- 970
Transition - 1.21-1.00-1.82 -- 5.48-1.00-2.67 --- 1005
Flower ----- 1.00-1.28-1.59 -- 4.00-1.00-2.12 --- 1040
This is what results from the "Useless" schedule[1]:
--------------- R A T I O S
-------- N-P-K ----------- K-Mg-Ca -------- PPM
VEG
week-1 1.32-1.00-2.41 -- 6.76-1.00-2.15 --- 323
week-2 1.85-1.00-3.06 -- 8.08-1.00-2.82 --- 574
week-3 2.06-1.00-3.31 -- 8.54-1.00-3.07 --- 667 [2]
BLOOM
week-1 1.00-1.29-1.88 -- 4.54-1.00-1.77 --- 745
week-2 1.00-1.47-1.70 -- 3.75-1.00-1.90 --- 767
week-3 1.00-1.52-1.70 -- 3.65-1.00-1.88 --- 875
week-4 1.00-1.72-1.87 -- 3.53-1.00-1.66 --- 946
week-5 1.00-2.21-2.25 -- 3.33-1.00-1.31 --- 966 [3]
week-6 1.00-2.70-2.36 -- 2.91-1.00-1.23 --- 966
week-7 1.00-3.16-2.72 -- 2.88-1.00-1.06 --- 930
That's the results using the unmodified schedule. However, I added GH liquid Koolbloom (LKB) during flower, and powdered Koolbloom (PKB) the final week (prior to 10-20 days of water only). The following is how it turned out:
week-2 1.00-1.92-2.16 -- 4.75-1.00-1.90 -- 888 [4]
week-3 1.00-2.12-2.31 -- 4.95-1.00-1.88 -- 1055 [5]
week-4 1.00-2.53-2.68 -- 5.06-1.00-1.66 -- 1187 [6]
week-5 1.00-4.09-3.34 -- 5.07-1.00-1.22 -- 739 [7]
[1] Useless schedule: http://forum.growkind.com/showthread.php?t=35174#.UmIsPhDK7Kc
[2] Repeat until bloom.
[3] Cut dose in half if using bloom booster.
[4] 2ml/gal LKB
[5] 3ml/gal LKB
[6] 4ml/gal LKB
[7] Cut base nutes in half, as described in the Useless schedule. Use 1.25g/gal PKB.
The above information was calculated using this spreadsheet. You can adjust your NPK ratios using that spreadsheet. You don't have to follow a rigid schedule. I wouldn't use LKB again. I think it's pointless. Maybe use half what I did (so it raises the PK ratio less).
Last edited:
rocko369
Well-Known Member
Replace res. Every 7-10 days until then just replace with water. unless your doing an ro type of situation then u would add wat ever the plant drank in notes,so if u start at 1200ppm and the next day it drank 300ppm just replace wit 300ppm back to 1200ppm.just my 2 cents!
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