[ShroomDr]

No im telling you that

if you water with 2.0ec and your run off is 2.2, they are being slightly over fed
if you water with 2.0ec and your run off is 1.8, they are being slightly under fed.
if you water with 0.1ec, your run off reading is useless because it cant be lower than 0.1ec.

(The run off of a previously fertilized substrate is always going to be higher than the plain water. Getting a reading of 2.0 or 4.0 is useless, you would only be guessing as too how much under/over fed they are) (However 4.0 is very hot imho).

Feed the plants with the exact same mix twice. The second time take the run off reading. If output is higher than input you are feeding too much, if its WAY higher, you are feeding WAY too much. The specific reading is irrelevant, its the change from previous that is important.

Im pretty sure i already said some of this, but i (re)use coco (90:10 fine coco:chunky perlite), in smart pots and 5Gal buckets, vertical lighting during flowering, on flood tables, using a recirculating reservoir, in tents, and normally use 5+8.

@ 6+9, my ec generally rises, and the girls seem a little too dark (thats why i adjust the micro [containing N] more [percentage wise; ie 1/6th less micro but only 1/9th less bloom].

This is what works in my environment under my conditions.
Im pretty sure 4.0ec is way way high. I had an AK-47 that was taking 2.8-3.0 before i understood ferts a little better. The AK did just as well @ 2.2, saving me $ on ferts.

[prophecy]

Thank you shroom I understand perfectly.

But if my water is 0.1EC and my run off is 4.0EC ... that could mean that they are so overfeed?

I think testing run off with 0.1EC water give me the real amount of nutrients in my soil. Doing this everytime is useless but for me that never tested it...it give me a real good idea if I'm on the good way or bad way. Now I know that I'm on bad way.

Remember I'm in pro-mix not in coco.

[ShroomDr]

Originally Posted by prophecy

Thank you shroom I understand perfectly.

But if my water is 0.1EC and my run off is 4.0EC ... that could mean that they are so overfeed?

First, i dont know shit about promix. I thought it has ferts in it already, and if it does, it should be watering with less nutrients, however i am not sure about the product.

Second, from my experience, if i ran 5Gal of 1.0ec through 5Gal of coco (note the equal vol nutrient:substrate) of 3.0, the substrate would be real close to 2.0. Same as, and more practically, if your run off is 2.2 and you want the substrate at 2.0, you would run an equal vol of nutrient @ 1.8. (Or half the vol, with twice the difference [half vol of sub @ 1.6ec]).

I have seen some say this doesnt work, but its always worked well for me.

Again i dont know shit about promix, but 4.0ec is really high; And its super-fucking-incredibly high if that is a run off reading after a 0.1 flush, regardless of substrate. Vol is a key factor here too, how much run off?

Originally Posted by prophecy

I think testing run off with 0.1EC water give me the real amount of nutrients in my soil. No it wont, If you follow the examples and find the sweet spot, where your feeding equals the runoff, you will then know a very good approximation of your 'real nutrients in your soil'.


Doing this everytime is useless Yes, but only after you have found your sweet spot

[prophecy]

My plant was ready to water. So I watered them normally and I measured the first 200ml of water that came out the pot.

The first reading was ALWAYS unmeasurable (too high more than 4.0EC).

After 4 liters of 0.1EC water into the soil the reading was at 0.5EC with 200ml sample.

[ShroomDr]

How much substrate (aka promix)? (Your runoff sample vol is not necessary; nor is an initial runoff reading useful.)

If there are nutes in the promix, you would have to adjust your estimate. So not knowing how 'hot' promix is, but guessing its relatively mid to light, and assuming you had 4l of promix, i would say your ec is close to 0.8-0.9. I would say it was 1.0 if the promix added nothing to the equation.

[prophecy]

I think pro-mix have no nutrients in it or very very few. After 1 week a clone already need nutrients.

My pot have 6 liters.

[dizzlekush]

@ShroomDr here's the breakdown for Dyna Gro Foliage Pro. i consider it the best Dyna Gro nutrient for MMJ growers and seeing as you don't have it added to your list why not make it available.

Fresh from Dyna themselves. the P2O5 and K20 conversions seem a bit off to me.

[the_extremist]

I get different numbers when I plug it into Cannastats.

Based on this label from Dynagro:

an 8oz bottle has a net weight of 310 grams. 8oz converted to milliliters is 236.5 ml.

Plug all this into Cannastats at 5 ml per gallon and I get:

-N----P----K--Ca---Mg-S
156--23--86--35---9---1

Still pretty far off, imho. Too much N, not nearly enough K, not quite enough P, still needs a Ca/Mg supplement.

[dizzlekush]

i kinda disagree. the NPK ratio works pretty perfect for vegetative growth, yes some Cal Mag supplementation is needed for veg and you need to do some tweaking for bloom but when it comes to a one part liquid nutrient the only thing that comes close in my eyes is CNS17 Hydro Grow and im not aware of it really comparing in side by side. but thanks for posting the Nutrient PPMs.

[the_extremist]

Oh yeah, for veg it would be great I agree. Definitely would have to add K for flower though.