Feel silly asking this but....

COflower

Member
What is ppm? I know it is parts per million, but what does that mean exactly and what is it referring to? Could someone please help me out and break it down for me so i understand?

Thank you
 

bioWheel

Well-Known Member
It's a ratio. And it means, for instance, that there's one part of some element in a million parts of water (for this example). So 1ppm Na (sodium) is one part Na and 1 million parts water. 1ug/ml is another way of saying ppm.
 

DeeTee

Well-Known Member
It's best to look at it this way, ppm's (parts per million) is the measured strength of you nutes, the higher the ppm's the stronger you nutes are, example: a seedling and young sprouts can take 100 to 250 ppm's, any stronger and you seedling will die from nute burn, as the plant gets older it can take up stronger nutes (higher ppm's) and so forth, use this chart as a guidline, you can adjust by observing your plant, I've also converted to ec should your meter read ec rather than ppm's, they are both the measurement (strength) of you nutes.

PPM for Hanna Chart PPM

Seedlings, Early Sprouts .......100 to 250 = .2 to .5 EC
Early Vegging ......................300 to 400 = .6 to .8 EC
Full Vegetation ....................450 to 700 = .9 to 1.4 EC
Early Blooming .....................750 to 950 = 1.5 to 1.9 EC
Full Mature Blooms ...............1000 to 1600 = 2 to 3.2 EC
 

JohnnySocko

Active Member
...And not taking away from what DT just said, but for clarification (from someone whose tap water starts at 600ppm) ...but ppms are just that: an assortment of dissolved solids are in water...all I'm saying is take into account your starting value (could be sulfur, iron, calcium, whatever ....many of us start with RO water (water at or near zero ppms) for just that reason
 
start yourt ppm at 500 and keep it there through out the grow and use advanced nutreints
thats what my they say at the hydroponic store
 

flippinkeysmakinGs

Well-Known Member
PPM is the EC (electro conductivity) times 500 or 700 usually. most ppm meters have a ppm500 and ppm700 setting.

example: your EC is 1, ppm500=500, PPM700=700. Your EC is 2.0 PPM500=1000, PPM700=1400. Equation ECx500=ppm500,,, ECx700=ppm700

Its just easier to read then EC because an EC of 1.6 and 1.7 is quite the difference. Also it might be good to inform you that if your are following feeding charts or advice from other using same nute line make sure to confirm if they are using ppm500 or ppm700 because a ppm of 1400 on ppm500 is a lot different than a 1400ppm of ppm700. Hope i was able to simplify that enough for you. REP+ would be appreciated
 

COflower

Member
Thanks for the clarification everyone. Deetee, i will be using this chart http://www.cannagardening.com/growguide. Your saying seedlings usually can only handle 100-250 ppm of nutrients but on the canna feeding schedule 910.

It's best to look at it this way, ppm's (parts per million) is the measured strength of you nutes, the higher the ppm's the stronger you nutes are, example: a seedling and young sprouts can take 100 to 250 ppm's, any stronger and you seedling will die from nute burn, as the plant gets older it can take up stronger nutes (higher ppm's) and so forth, use this chart as a guidline, you can adjust by observing your plant, I've also converted to ec should your meter read ec rather than ppm's, they are both the measurement (strength) of you nutes.

PPM for Hanna Chart PPM

Seedlings, Early Sprouts .......100 to 250 = .2 to .5 EC
Early Vegging ......................300 to 400 = .6 to .8 EC
Full Vegetation ....................450 to 700 = .9 to 1.4 EC
Early Blooming .....................750 to 950 = 1.5 to 1.9 EC
Full Mature Blooms ...............1000 to 1600 = 2 to 3.2 EC
 

COflower

Member
Do i need to measure my water and fertilizers ppm separately and add them together to make sure that they are at the appropriate level for the specific stage of growth?
 

DeeTee

Well-Known Member
You measure the two (water,ferts) combined then adjust your ppm's, and I seriously doubt any seedling can handle 910 ppm's, but it's your choice, don't say I didn't warn you.
 
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