How do I tell if my PPM/EC is too high or too low?

Smokin Moose

Fallen Cannabis Warrior & Ex Moderator
It's simple to find out if you are using too much food or not enough by watching the nutrient concentration levels in your tanks day to day. Don't be concerned with the exact reading, rather watch how it rises and falls from each day to the next. The differences between when you put the solution into the tank and the readings you get several hours later or the next day are what tell you if your plant is eating, drinking or happy.

Start with 1.00 EC (or a SAFE nutrient strength). Next day, if it reads 1.4, it means your plants have been using water and your nutrient solution is becoming more concentrated. This means the concentration of nutrients is too high, so you dilute.

If the meter reads lower than the previous day, 0.7 say, it tells you that the plants are eating nutrients faster than they are drinking water, so you should increase your nutrient strength. If it remains the same, your feeding schedule is on target for now. The nutrient/water intake fluctuates with the growth of the plant, so you must continually monitor it day to day.

Your plants will tell you the optimum nutrient levels. When they are receiving optimum food and water, the readings remain constant. The more you do it, the easier it gets. The reason no one can tell you what PPM/EC levels to use is because every garden is different and every plant has different requirements due to their particular environment. That's why you have a ball park starting figure, but after that your plants will tell you almost exactly what they require.
 
ok lets see, i checked my water for 3 days know and my reading on the 1st day was at 3.0 ec. On the 2nd day it read 3.1 ec, so i added a gallon of ph checked water to dilute correct? Now on the 3rd day today it read 2.6 ec, so according to your post i must add some nutes correct? The question is how far can the number slide up or down before you add more water or more nutes to your res. Also how much water or nutes to put in if you must add??? Hope this is understandable, please advise.
R.E.C.
 
redeyechiller,
i have no knowledge in hydro grows, but from reading smokeys post, it appears you want the level to be at 1.00.
if its below that, the plant is using more nutes than water, there fore add more nutes to the water.
if its above the 1.00, the plant is drinking more water than using nutes so you need to dilute with more water.
the one factor i dont have a clue about is what number you want the ppm/ec to be at.
 
im also wondering this same thing.... i just started my 3rd ------------ grow and have done without a PPM meter for the past 2...finally once my PH meter decided to take a shit...i figured id splurge and get a ph/ppm meter...and for the past 2 grows iv always had problems with nute burn or undernuting so im trying to get a good grasp on how much to start with and whatnot. and also im interested in redeyes question as well. cus i feel like this may be a situation i run into
 
redeyechiller,
i have no knowledge in hydro grows, but from reading smokeys post, it appears you want the level to be at 1.00.
if its below that, the plant is using more nutes than water, there fore add more nutes to the water.
if its above the 1.00, the plant is drinking more water than using nutes so you need to dilute with more water.
the one factor i dont have a clue about is what number you want the ppm/ec to be at.

what he was saying there is the number you start with doesnt mater but if you start at three and the next day it is at 3.5 nutes too strong add water back to 3. the next day if its at 2.5 nutes too low add little more nutes to 3. the next day if it is at three you are on about the correct feeding schedule. it will flucuate but the closer to the base reading you stay, the closer to optimal water to nute intake ratio. I hope this helps alittle
 
what is your base number based on is it based on what your water is at when you add what you think is an ideal mix of nutes
 
Dont think this thread was to tell you what ppm/EC to set your res at it was to explain how to tell and manage your res if your girls are eating to much or not anoth.

Think max strength nutes should be about 1.8EC in veg and 2.8 in flowering well thats what dutch pro are.
 
I was told by a grower with vast experience that you should use the double up method. So if your nute is EC 1.00 then the next day it is EC 0.8 you should then bring up the nutes to EC 1.2 as your plant has used 0.2 and then you need to give it another 0.2 to to make up for what it is using. If you keep doing this.. you will be giving the plant what it needs and be one step ahead. I did try this a got a mega beast of a plant.
If you carry this on through all stages the plant will keep telling you what it needs.
Then run the last week with no nutes at all but just water.
 
This is a very good read - Personally-I would never exceed 2.5 in flower!

For veg I keep The EC(ppm) @ 1.4-1.8
And in flower 2.2-2.5
PH 5.5 - 5.9

Like the article states though.. every garden is different!
 
I think i get it...

so if the base is 1.0

and the next day it's at 1.4.
The nutrients are too strong!! so i add more water to get back to 1.

so the next day if it's at 0.7
The nuts are too low so i add a little bit more nutrients. to equal back to 1.
 
what if your using coco coir and there isnt a reservoir to work out if they drinking or eating :)

I'd consider that to be a run-to-waste hydroponic growing method. You can measure your runoff and compare it to what went in (assuming you water enough to have runoff, which is a good idea to help flush any nutrient (salt) buildup out of your containers.

I had better results by not using 100% coco coir but, instead, mixing it with perlite. This gave me better drainage and allowed the roots to get oxygen. I assume that you are also not using 100% coco as your medium - but that is just a guess.
 
I'd consider that to be a run-to-waste hydroponic growing method. You can measure your runoff and compare it to what went in (assuming you water enough to have runoff, which is a good idea to help flush any nutrient (salt) buildup out of your containers.

I had better results by not using 100% coco coir but, instead, mixing it with perlite. This gave me better drainage and allowed the roots to get oxygen. I assume that you are also not using 100% coco as your medium - but that is just a guess.


yeah no ,im using 75/25 coco perlite and am watering with run off though, how often do you water?

I thought until it starts to dry out but for mine is taking sometimes 5-7 days and concerned im not doing it as much as i should. Kinda feel i should be watering more but dont want to in case of root rot ? *shrug
 
yeah no ,im using 75/25 coco perlite

I've become wary of using too much coco. I'm starting to wonder if even a 50:50 mix is a little to much (for me). Instead of using perlite to cut the coco, I have almost begun thinking of it as using coco to cut the perlite, lol.

how often do you water?

At the risk of appearing to be a smart-***, I water whenever the plant needs it. It's going to vary depending on the size of the plant, the size of the container, amount of root mass, temperature - and humidity - of the grow room, and so on. The amount of air that is moving across the plants will play a big part, too, because plants use transpiration as sort of a natural cooling device (I have read that a large oak tree can actually transpire up to 40,000 gallons of water in a year).

I thought until it starts to dry out

You thought correctly, methinks.

but for mine is taking sometimes 5-7 days and concerned im not doing it as much as i should. Kinda feel i should be watering more but dont want to in case of root rot ? *shrug

Ah, the old feeling of, "I should be doing something... even if it's wrong." That has been the bane of many new growers' grows (and no few new cooks' first meals), lol. The pots will get a lot lighter as their moisture content drops. Then the plants will start to droop. At that point, if you water, they'll perk right up and the container will be heavier again. I would not consider that to be unduly stressful on the plants (only, perhaps, on the grower ;) ) - and certainly far less stressful than regularly overwatering - as long as it is not taken to extremes, and the knowledge and "feel" one gets from the experience is useful.

A man who is thirsty will, if offered water, drink his fill - but a man who has drowned will never drink again.
 
I have plagron terra grow/bloom, on package is writen max. 5ml per liter - is this per plant or ... ? If I have 4 plants, then I must add 20ml per liter and water all of them?
 
It's simple to find out if you are using too much food or not enough by watching the nutrient concentration levels in your tanks day to day. Don't be concerned with the exact reading, rather watch how it rises and falls from each day to the next. The differences between when you put the solution into the tank and the readings you get several hours later or the next day are what tell you if your plant is eating, drinking or happy.

Start with 1.00 EC (or a SAFE nutrient strength). Next day, if it reads 1.4, it means your plants have been using water and your nutrient solution is becoming more concentrated. This means the concentration of nutrients is too high, so you dilute.

If the meter reads lower than the previous day, 0.7 say, it tells you that the plants are eating nutrients faster than they are drinking water, so you should increase your nutrient strength. If it remains the same, your feeding schedule is on target for now. The nutrient/water intake fluctuates with the growth of the plant, so you must continually monitor it day to day.

Your plants will tell you the optimum nutrient levels. When they are receiving optimum food and water, the readings remain constant. The more you do it, the easier it gets. The reason no one can tell you what PPM/EC levels to use is because every garden is different and every plant has different requirements due to their particular environment. That's why you have a ball park starting figure, but after that your plants will tell you almost exactly what they require.

Thanks for explaining to us...
 
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