Safe Ppm Feeding Ranges For Coco/perlite (grotek)

[Trentski420]

Hi all so I'm beginning week 5 of my 2nd grow so this shows you the importance of needing this question answered asap.. my first grow went off without a hitch using coco/perlite/peat mix... This time however I did 4 that way and another 4 without the peat (closer to hydro;quicker absorbing media etc etc) so for the PEAT mix I went all the way up too a maximum of 1400ppm looking back I over fed and should have stopped somewhere in the 1200ppm range... So for the coco/perlite (NO PEAT) I THINK I read your not supposed to exceed 550ppm in a feeding (I think!) Is this correct? I do understand they feed more frequent etc. I don't need a lecture on this.. I know all nutrient lines are not the same I am using Grotek line from BC Canada if this helps

Edit: 1000w cool tube generally runs between 25-26 C 50% rh

 

[Trentski420]

Shit almost forgot one of most important parts of my question ... So I've read time and time again that coco/perlite feed once up too twice everyday! Now my question is this at the peak of feeding? Say mid bloom? Or is this right from the get go? Mine started out every 3-4 days beginning flower and are working there way to every 2-3 days now (day 28)...

 

[Eli Bloom]

I'm feeding at about 800 ppm right now and my plants seem happy. i'll let someone else weigh in with a definitive answer on that.

regarding watering frequency it's going to depend on the size of your pot, veg time (root mass), and room climate (temp and RH). you're just going to have to get a feel for it but the 2x a day would not be right from the get go (for veg anyway).

with coco you never want the medium to completely dry out as you would in soil, which is why a lot of people have great success using blumats.

what size pots are you in? how long did you veg? do you notice that the pots feel light before feeding?

 

[visajoe1]

First, get away from using ppm measurement. EC is what you want to use. There is two different ppm scales, and EC more accurately measure what we are looking for. The most common ppm scale is .5, so double your ppm number and that is about the EC level.

You said you ran 1200-1400ppm which is an exceedingly high EC of approximately 2.4-2.8.
Most people run hydro/coco at 1.2EC in veg and as high as 1.6EC in flower for heavy feeding.
This is assuming you are using RO water

In coco, you should be in a pot that allows you to water everyday without causing it to be over watered. If you have to wait a couple days or more, the container is too large and you'll have less oxygen at the roots than you could have with a properly sized container. Leave them for now, just know for next time.

My understanding with peat is that its easy to over water because it holds so much. So, I would just error on the side of dry than wet. Never heard anything about a limit to feeding though.

I recommend you flush them, then resume feeding with lower EC levels. You'll be fine.
Dont forget to ph to 5.8

 

[Trentski420]

Ok well the 1200-1400ppm was my previous first grow which I already admitted I over fed and they had Peat In the mix was not 50/50 coco/perlite.. and they are in 3gallon and veg'd for 2 months so it's too small before it would be too big... I water until 10-20% run off which is approx 3L or a gallon.. the answer I get is to go buy new equipment lol thx guys

 

[Trentski420]

I have been PH'ing to 5.8 but since bloom have been letting it slide to 6.0 is this not a good idea?

 

[Trentski420]

When it comes to VPD your taking measurements of leaf temperatures if I have different temp/RH (microclimate) below, because I got a tight SCROG in a closet do the pots evaporate as if the VPD did not represent what it shows atop the canopy? It's not too far off that it should make a difference ... Are my pots going to dry daily if I use a lower EC/PPM? Can no body tell me if I should be going lower than 500-600ppm in week 5 of flower on 50/50 coco/perlite

 

[visajoe1]

I have been PH'ing to 5.8 but since bloom have been letting it slide to 6.0 is this not a good idea?

Letting it slide is good, this chart may help

 

[Eli Bloom]

Are my pots going to dry daily if I use a lower EC/PPM? Can no body tell me if I should be going lower than 500-600ppm in week 5 of flower on 50/50 coco/perlite

A lower PPM will not have any impact on how quickly your medium dries out.

I would not go lower than 500ppm in week 5 of flower.

 

[Trentski420]

Letting it slide is good, this chart may help

Ya I've been meaning to get a copy of that printed out and lamenated

 

[Pimples]

First, get away from using ppm measurement. EC is what you want to use. There is two different ppm scales, and EC more accurately measure what we are looking for. The most common ppm scale is .5, so double your ppm number and that is about the EC level.

You said you ran 1200-1400ppm which is an exceedingly high EC of approximately 2.4-2.8.
Most people run hydro/coco at 1.2EC in veg and as high as 1.6EC in flower for heavy feeding.
This is assuming you are using RO water

In coco, you should be in a pot that allows you to water everyday without causing it to be over watered. If you have to wait a couple days or more, the container is too large and you'll have less oxygen at the roots than you could have with a properly sized container. Leave them for now, just know for next time.

My understanding with peat is that its easy to over water because it holds so much. So, I would just error on the side of dry than wet. Never heard anything about a limit to feeding though.

I recommend you flush them, then resume feeding with lower EC levels. You'll be fine.
Dont forget to ph to 5.8

Listen to this ^^^^.

 

[Eli Bloom]

So using EC I don't like to go higher than 1.2...

 

[Pimples]

So using EC I don't like to go higher than 1.2...

Only one way to find out

 

[MidwestToker]

When it comes to VPD your taking measurements of leaf temperatures if I have different temp/RH (microclimate) below, because I got a tight SCROG in a closet do the pots evaporate as if the VPD did not represent what it shows atop the canopy? It's not too far off that it should make a difference ... Are my pots going to dry daily if I use a lower EC/PPM? Can no body tell me if I should be going lower than 500-600ppm in week 5 of flower on 50/50 coco/perlite

What do you want to know specifically? I rarely feed my coir over 1.0 ec or 500 ppm max in flower. Most of my veg is in the 400-450 ppm range.

 

[Trentski420]

What do you want to know specifically? I rarely feed my coir over 1.0 ec or 500 ppm max in flower. Most of my veg is in the 400-450 ppm range.

Thank you very much that was like pulling teeth all this EC thus EC that thx guys I will switch it up but an answer that helps today is nice

I took her around 550-600ppm and noticed tiny burning of tips so I figured it out but the confirmation is nice

 

[Trentski420]

My girls been getting fed every 2-3 day(500-600ppm) my plan is too give em a good flush keep ppm at or below 500ppm drop runoff from 20-30% too 10% and attempt to force em daily unless they're clearly not ready... if there's any reason someone thinks that's not a good idea let me know please... (they do seem to be doing good enough that I actually don't see a need to get them feeding daily but it's what I've come to understand is best w/ 50/50 coco/perlite)

 

[MidwestToker]

My girls been getting fed every 2-3 day(500-600ppm) my plan is too give em a good flush keep ppm at or below 500ppm drop runoff from 20-30% too 10% and attempt to force em daily unless they're clearly not ready... if there's any reason someone thinks that's not a good idea let me know please... (they do seem to be doing good enough that I actually don't see a need to get them feeding daily but it's what I've come to understand is best w/ 50/50 coco/perlite)

I just make sure I have a 20% run-off once a week.

 

[Trentski420]

I just make sure I have a 20% run-off once a week.

Ya I like that idea I just gave them all a mid cycle flush only 1 needed more time to dry the coco/perlite followed flush with 340ppm and the coco/perlite/peat followed the flush with 720 ppm

 

[straincreation]

What do you want to know specifically? I rarely feed my coir over 1.0 ec or 500 ppm max in flower. Most of my veg is in the 400-450 ppm range.

What are your yields like at 500 ppm?

 

[UncleRomulus]

Ok well the 1200-1400ppm was my previous first grow which I already admitted I over fed and they had Peat In the mix was not 50/50 coco/perlite.. and they are in 3gallon and veg'd for 2 months so it's too small before it would be too big... I water until 10-20% run off which is approx 3L or a gallon.. the answer I get is to go buy new equipment lol thx guys

I don’t really see anyone telling ya to go buy new equipment but then again I am half blind and stoned.
Anyways 3 gallons is a fairly big container for coco, especially coco/perlite. (Maybe just keep in mind for next time) if you are running a scrog or sea of green with several small/moderate sized plants 3 gal is slightly overkill IMO. 1-2 gal would be fine. It’s fine that you used 3 gals just don’t water as much as often recommended, at least till they are mature. Doesn’t matter what it says online, if it don’t look like you should water and it’s heavy, don’t go near it with the ol waterin can