EC, PPM???

Okay newbie here having trouble with conversions. Let me explain my set up first. I am using a recirculating system with Canna Aqua nutrients. I have a Hanna Combo Ph/EC/PPM Meter (the black one). I also have questions about adding my initial PPM from tap water. Here is what Canna says about Aqua:
Seedlings EC .7-1.1
Veg phase 1 EC .9-1.3
Veg Phase 2 EC 1.2-1.6
Flower Phase 1 EC 1.4-1.8
Flower Phase 2 EC 1.6-2.0
Flower Phase 3 EC 1.0-1.4
Flower Phase 4 EC 0
Now Canna says they add .4 EC into these numbers for tap water. Do I do this? I'd like to use PPM. My tap water is 210 PPM.
Canna also says they convert with a .74 conversion factor. Please Explain. I know there are different conversions which is confusing, but my Hanna Meter is EC 1.0 = 500 PPM. I do not think these are compatible because a .74 conversion factor would be EC 1.0 = 740 PPM.
I basically have to modify Canna's recommendation from .4 EC to .2 EC?? Then I have to somehow get their PPM Conversion to Hanna's .5 conversion??
What the Heck is going on here? I'm so confused. I don't know what to do to get an accurate reading/ feeding schedule. Please let me know if I should add my tap water PPM to my recommended PPM and include it. thanks

The EC on your meter is the same as Canna`s EC. EC is universal, ppm isnt so you need to know the meters conversion factor to go from ppm to EC. In a nutshell, use EC not ppm

It seems to me PPM gives a more accurate measurement as the PPM will fluctuate with nutrient uptake. Does EC fluctuate as well with nutrient uptake?

The EC will change but (depending on the meter) it`s harder to see changes below 0.1
PPM can be used to track very small changes but for most methods a 0.1EC step is plenty.

.7-1.1 EC would fry most seedlings at the low end of that scale.

In the beginning i'd go quarter strength. Which would be around .2-.4EC numbers i've used on seedlings with success.

firsttimeARE said:

.7-1.1 EC would fry most seedlings at the low end of that scale.

In the beginning i'd go quarter strength. Which would be around .2-.4EC numbers i've used on seedlings with success.

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Ya they're leave are a little yellow and curled over a bit. Right now I have 580 ppm. At what stage do you consider a seedling to be in the beginning stage of veg growth? Mine were doing just fine, but they got some heat stress, then my heater went out so they got cold (about a week ago) and they have stayed pretty much the same since, no growth. But the leaves still look the same. :/ So maybe consider the first 2 weeks seedling growth? I am watering for 30 min every 4 hours.

my ec meter is strange. I have my water at 220 ppm with nothing in it, but the ec meter says its like 400's and I'm sure its not the ppm lol.

Generally a healthy plant will keep adding two fingers. Starts off with cotyledons and two single bladed leafs. Next set will be three bladed leafs. Next set five. Set after 7. Set after 9. And ive seen it in select plants 11 bladed leafs. Havent seen 13 ever.

Generally between 5-7 bladed leafs indicate a plant is vegging

busybee321 said:

It seems to me PPM gives a more accurate measurement as the PPM will fluctuate with nutrient uptake. Does EC fluctuate as well with nutrient uptake?

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Yep.

ya I only have 2 sets of leaves. I wish I could send some pics to show you what I've got. So after I have 5-7 sets of leaves I can fertilize at regular strength, but up until then only about 1/4?

firsttimeARE said:

.7-1.1 EC would fry most seedlings at the low end of that scale.

In the beginning i'd go quarter strength. Which would be around .2-.4EC numbers i've used on seedlings with success.

Click to expand...

My experience is quite different. However, I work hard to maintain higher RH in my veg room and that means the babies take up less water- and therefore nutrient strength can be higher.

busybee321 said:

Ya they're leave are a little yellow and curled over a bit. Right now I have 580 ppm. At what stage do you consider a seedling to be in the beginning stage of veg growth? Mine were doing just fine, but they got some heat stress, then my heater went out so they got cold (about a week ago) and they have stayed pretty much the same since, no growth. But the leaves still look the same. :/ So maybe consider the first 2 weeks seedling growth? I am watering for 30 min every 4 hours.

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Warm them up into at least the low 70s, 75 is ideal.

Its 73 in there right now, I will wait a couple days to see if they do better and if not I have more seed to use, just hate to waste seed and nutes :/

General guide should be good for most.

Seedling stage .2-.6
Early veg .4-.8
Late veg .8-1.2
Early flower 1.0-1.5
Mid flower 1.2-1.5
Late flower .8-1.2

You are recirc so you can go a little higher. I do regular dwc. Most of my plants like around 1.2-1.5 max. I grow 4-5foot plants.

Ultimately you will want to learn what to look for in your plants. It helps running the same strain a few gos as all strains are different.

Take notes and record ph and ec every time you check it. Compare it to pH availability charts and make sure youre hitting all the nutrients that the plant needs. Keep it in range of macros at all times and let it drift occasionally down to the micros and you should be well on your way.

busybee321 said:

Its 73 in there right now, I will wait a couple days to see if they do better and if not I have more seed to use, just hate to waste seed and nutes :/

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You're learning, right? Then they aren't going to waste!

ttystikk said:

My experience is quite different. However, I work hard to maintain higher RH in my veg room and that means the babies take up less water- and therefore nutrient strength can be higher.

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Why what do you feed your seedlings? Most ive gone was .6 but ive had plants that didnt like that high

firsttimeARE said:

Why what do you feed your seedlings? Most ive gone was .6 but ive had plants that didnt like that high

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I run clones exclusively, so my experience is with these.

I am learning, maybe a few grows and I will be giving people advice on the forums here haha. If I can get my meter to work with EC i'll do that. Otherwise its going to be ppm for me. Question, when you say .2-.6 EC on seedlings does that include the EC of the plain water. My water is 220 ppm so I guess .4 EC

No. You dont know whats in tap so u cant count it

Please explain...everything I have read says to include what is in tap. For example, if I need to have 1000 ppm in my solution and my water is 220ppm at tap, I add 780 ppm nutes.