Ppm/ec

Mhogs

Well-Known Member
Quick question. I think I have my answer but curious to see what others have to say.
Dwc grow, barneys farm ww, and headband clone from a friend.
Setup: 5gallon bubble buckets. Hydrafarm airpump 15L/min. 5in air stones each bucket. 3x3 tent, 1300watt led,100watt supplement CFL, humidifer, 4in inline running air out to dryer duct.
Running Advanced nutrients (grow,micro,bloom). Temps with lights on run 76-79f, off 71-73f. Humidity stay around 50- 60%. Bucket temps between 63-67f.
Vegged for 5weeks. Topped and lst throughout.
Started with175ppm, ph5.9 each bucket until tru 5 finger leave present since they were clones(6-8days?). Jumped to 375-400ppm for 1.5 wks. 3rd actual week of veg, jumped to 700ppm. 4th&5th week to 950-1200ppm. Res change. Flipped to 12/12.
Never any sign of burnt tips or stunting.
Plants look great, bushy and healthy.
I started looking at my 'ec' readings and I'm always 2.7-3.0 which I'm reading is way to high. I feed on mondays only and always top up with filtered water that has a ppm of 120 and ph'd to 5.9. I might bump each bucket with a few mls of bloom to keep my ppm up near my target #.
2nd week of flower. I started adding 'moab'.
My water level is fluctuating as it should, ph always stays at 6.0-6.2 now that I'm in flower. I never need to put any buffer in mid week when I'm checking numbers. No sign of any problems. Should I even be concerned about these 'ec' readings?
First hydro/dec grow.
Thoughts?
 

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Mhogs

Well-Known Member
You're right. I was confused. Hence my question. So having a ppm of 1400-1600 will never give me an ec of 2.2-2.4. Thank you for clearing that up. For some reason I thought I could continue feeding heavy but somehow manage an optimal ec reading.
 

Renfro

Well-Known Member
So having a ppm of 1400-1600 will never give me an ec of 2.2-2.4
EC of 2.2 = 2200uS and that is 1100 PPM @ 0.5 conversion.
2.4 = 1200 PPM

Know that if the PPM meter uses a 0.7 conversion rate:
EC of 2.2 = 1540 PPM
2.4 = 1680 PPM
 

Renfro

Well-Known Member
I like to stay at no more than 2.4 EC / 1200 PPM. Beyond that I get tip burn on many strains. Staying a hair lower like 1150 PPM is where I like to be.
 
I like to stay at no more than 2.4 EC / 1200 PPM. Beyond that I get tip burn on many strains. Staying a hair lower like 1150 PPM is where I like to be.
I just noticed that the tips are burnt and curling on mine. When I set the res last Friday I set the pH at 6.0 and the ppm at 1000. I noticed that as the week goes on the ppm and pH went up. Is this normal for a hydro table indoor grow? Using rw cubes and feeding for 15 minutes 4 times daily. Ppm are currently at 1550. Should I reduce even though I will be resetting res tomorrow?
 

diggs99

Well-Known Member
you'll probably think i'm full of it but my last run was 0.7 with 0.2 of it being well water. 250ppm nutes 1xday feed

Nah i think ppm/ec is very strain dependent and im also a believer in that many growers could probably get away with using much lower ppm mixes.

I grew one strain from seedsman(gelat.og) i had to keep ppms low for that bunch, they werent fond on the strong stuff.
 

Aye1frmDay1ny

Well-Known Member
EC of 2.2 = 2200uS and that is 1100 PPM @ 0.5 conversion.
2.4 = 1200 PPM

Know that if the PPM meter uses a 0.7 conversion rate:
EC of 2.2 = 1540 PPM
2.4 = 1680 PPM
I have tds/Ec reader in Us/cm ... I have no decimal so how do I convert it? Is an eC of 2000 = to 2.0 EC ? And how does one lower EC and keep ph and vice versa ?
 

AquaTerra

Well-Known Member
I have tds/Ec reader in Us/cm ... I have no decimal so how do I convert it? Is an eC of 2000 = to 2.0 EC ? And how does one lower EC and keep ph and vice versa ?
You lower EC by adding in more plain water. This will of course change the ph but would depend on what the ph of your water is.
 
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