Runoff Ph 5.1 and EC 3.1 what does this mean?

[Bangarang]

I have been researching this and have not been able to come up with a clear answer.

Long story short. I am in W6/7 and have fed GH 4 Micro 7 Bloom 3 Cal/Mg and 1ml Moab with 2ml Fire. The EC is 2.2 and the Ph of 6.0. I fed every three days and am in Canna Coco. My girls seem to have stalled out on me. The look beautiful but are not getting there last push. Ok any plant with a hint of purple looks great if it has green leaves aka Headband or OG they are yellowing fast.

I fed today and gathered some runoff and found that my EC: 3.1 and Ph: 5.1. What have i done? Does the plant remain healthy looking but stop growing because it is able to take up elements within its range but is locking out P and K? Any information would be great and even a clear lesson on how to interpret these reading in the future.

 

[Joe Fresh]

ph at 5.1 means your on the verge of a lock out..below 5 is for sure lockout...

i would flush...but i read on canna's site about coco to never water is less than 0.6 EC...so when flushing i would maybe give 100ppm cal/mag, and 200 ppm base nutes...

i have not used coco yet..but sounds to me like this is the route to go...i would get EC to 1.5-2.0 in the runoff...but thats just me, others mught suggest you flush till runoff is less than 500 ppm or 1.0EC..i have not used coco so listen to those who have


to answer "what have you done"...simple...you over fed, not nute burn, but rather by consistently feeding by say 100ppm too much, it wont hurt the plant, but it will build up in the medium..causing salt buildup...salt build up lowers the ph of the growing medium leading to lockout...fist nutes to get locked out will be calcium and potassium....and sometimes when your right on the verge of lockout like you are, plants look healthy because they have been able to still take in some nutes, but not all...but by time you see there is a problem, and decide to flush even though plants are still looking healthy but you know something is up...you will see plants yellow a bit following the flush, next watering or even that same day with after the last flush, its best to recharge the medium with a 3/4 feeding, this will make sure the PH stays and does not fluctuate after a large flush...

but my experience is with soil and peat, not coco....next run i plan to try coco

 

[Seamaiden]

I'm in agreement with Mr. Fresh regarding nutrient build-up in the media, I'm damn near hunnert percent positive that's what you've done IF you've been feeding at every watering and not tapering down at any time.

However, I'm in disagreement with others who use run-off to try to figure out what's going on IN the root zone. Do a slurry test, IME that's really the best way to figure out what's actually going on.

Since you say you're in coir and you've been feeding only at a pH of 6, I'd say that you've not only caused sufficient build-up to cause a toxicity, but if indeed the pH in the rhizosphere is not within the better coir range (again IME, but not everyone's) of 5.8-6.2 then you'll be adding lock-out on top of toxicity.

Considering how far along into flowering you are and assuming no more than 10wks flowering time, I would immediately start tapering down really hard on the feed until either the numbers are more in line or the girls are looking better (there's really not a lot that's going to happen at this point other than building more bud).

Also, you've never mentioned environmental parameters (temps and RH), and those parameters play quite a role in this stuff as well.

 

[Bangarang]

Temp - 79-81 with Co2 1200 45-65% rh
This always seems to happen when i try using moab. I am not hitting them hard by any means. I can slam them with Overdrive and never have problems; in fact great results. But wanted to figure out Moab and i guess i just cant win. Third try and i am going to have to tap out on this. I flush with OgBiowar anytime i make a major change in additives. I.e. amino aid to big bud to moab.
I have two that i am using Moab on and two that i am using overdrive and the OD is right in range.

 

[Coir]

Have you ever mixed MOAB in water and checked the pH? You might find it rather revealing.

 

[Seamaiden]

Temp - 79-81 with Co2 1200 45-65% rh
This always seems to happen when i try using moab. I am not hitting them hard by any means. I can slam them with Overdrive and never have problems; in fact great results. But wanted to figure out Moab and i guess i just cant win. Third try and i am going to have to tap out on this. I flush with OgBiowar anytime i make a major change in additives. I.e. amino aid to big bud to moab.
I have two that i am using Moab on and two that i am using overdrive and the OD is right in range.

I can't say the parameters would have played such a huge role here, especially if you're running CO2 (which I'm not very familiar with). But it seems you kinda know the answer here, especially if this *isn't* a problem you've been watching develop over time and can repeat by using that product. I'm going to assume you're staying super on top of monitoring pH in and out here, too, but if not then Coir makes a good point.

 

[Jalisco Kid]

You might have a bioherd getting out of control. If you have 5.1 pH coming out imagine what is setting at your roots. I like to use a big syringe with 1/4 drip hose attached one end cut at a 45*. I usually will take a reading, then inject about 4 oz into the root ball wait 10 min and take a reading. You do this enough and you will get a sense of what is going on down there. Next run water with 250 ppm every 4 th watering. better at lights off. JK
If you have enough plants stop guessing and take a water and leaf sample to a lab.

 

[ftwendy]

If you have enough plants stop guessing and take a water and leaf sample to a lab.

How does one go about finding a lab for testing? I know most Universities have them, but can't imagine waltzing in there uninvited with my reefer leaves and pot lingo.

Any tips on where and how to ask?

 

[Jalisco Kid]

You look up a lab that work ag. Most labs can do this but ag labs are cheaper. Your leaf will be dried and chopped so it really does not look like you think. You send it in with not pot lingo and wait for your results. Do this with your best plant also to give you a guideline to shoot for. Most labs will email you a guideline how they want plant/root soil/water to be treated for shipped. JK
And make up a name like Hidden valley organic farms and use that as your email.

 

[Coir]

All three of these labs do water and tissue analysis. Whether or not they test cannabis tissue, I do not know but I'm sure they would. The water analysis won't matter as far as that goes. I have dealt with 2 of them for greenhouse crops water and tissue testing over the years.
You might want to send an email asking what their policy is for medical cannabis and see what they have to say. Most of the time, the results can be emailed so setting up a safe email address just for testing should be easy enough.
One thing to remember is that once you get tissue analysis results, you have to know what the numbers mean and that can be very subjective!

http://www.mmilabs.com/

 

[gliders420]

Did this go anywhere?

 

[crocodile og]

Not enough run-off.

Sodium will interfere with calcium and potassium uptake.

Flush with corrected nute solution untill run-off is the same as drain water.

Canna says lots of things. But they dont say their coco can be a little salty at times. As most coco mediums can be.

Allowing the pots to sit in run-off will result in the water and salts it contains being reabsorbed.

Next run figure out a better drainage situation and keep an eye on the run-off pH and E.C.

And dont reuse coco without thoroughly rinsing it. Or better yet dont reuse it at all.

 

[growchick421]

ph at 5.1 means your on the verge of a lock out..below 5 is for sure lockout...

i would flush...but i read on canna's site about coco to never water is less than 0.6 EC...so when flushing i would maybe give 100ppm cal/mag, and 200 ppm base nutes...

i have not used coco yet..but sounds to me like this is the route to go...i would get EC to 1.5-2.0 in the runoff...but thats just me, others mught suggest you flush till runoff is less than 500 ppm or 1.0EC..i have not used coco so listen to those who have


to answer "what have you done"...simple...you over fed, not nute burn, but rather by consistently feeding by say 100ppm too much, it wont hurt the plant, but it will build up in the medium..causing salt buildup...salt build up lowers the ph of the growing medium leading to lockout...fist nutes to get locked out will be calcium and potassium....and sometimes when your right on the verge of lockout like you are, plants look healthy because they have been able to still take in some nutes, but not all...but by time you see there is a problem, and decide to flush even though plants are still looking healthy but you know something is up...you will see plants yellow a bit following the flush, next watering or even that same day with after the last flush, its best to recharge the medium with a 3/4 feeding, this will make sure the PH stays and does not fluctuate after a large flush...

but my experience is with soil and peat, not coco....next run i plan to try coco

So as Joe said, the pH being low on the run off is a sign of salt build up. Ok, so what if ur pH is coming out the same as going in but the ppm is not?? The last few feedings I have checked the run off, going into the plant the numbers were 780 ppm and 6.2 pH. When checking the runoff the pH was at 6.2 but the ppm was only reading ---. Is this a sign of salt (or any other kind of) build up?? And if so what would be good ways to remedy the situation?? I keep reading that flushing coco with h2o is not a good idea. I am using the Botanicare ready grow moisture formula, it is an amended coco pearlite mix. I'm still in veg and would like to get things situated before I go into bloom.
Thanks for the future info :D

 

[Seamaiden]

Have you tried a slurry test, instead? I feel that it's a better method for problem-solving.

 

[Coir]

So as Joe said, the pH being low on the run off is a sign of salt build up. Ok, so what if ur pH is coming out the same as going in but the ppm is not?? The last few feedings I have checked the run off, going into the plant the numbers were 780 ppm and 6.2 pH. When checking the runoff the pH was at 6.2 but the ppm was only reading ---. Is this a sign of salt (or any other kind of) build up?? And if so what would be good ways to remedy the situation?? I keep reading that flushing coco with h2o is not a good idea. I am using the Botanicare ready grow moisture formula, it is an amended coco pearlite mix. I'm still in veg and would like to get things situated before I go into bloom.
Thanks for the future info :D

What kind of meter are you using? If "---" is from the level being too high for the meter you definitely have a problem unless the meter is faulty or can only read very low PPM's.

 

[growchick421]

What kind of meter are you using? If "---" is from the level being too high for the meter you definitely have a problem unless the meter is faulty or can only read very low PPM's.

I want to say that it is a blue hanna ppm reader. Ill check it in things I have already have checked just to make sure it is still working, which makes me think that it is coming out to high. However my plant is looking green happy and thriving,(pic below).
I have an active air 2way meter by hydro farm to check the moisture level and to give a 2nd reading of pH. Ill try a slurry test too. I need to trans her in the next day or so, so I will probably flush her before I do, still not sure if a strait flush or a low ppm flush would be better :shifty:

 

[crocodile og]

Or the meter might being reading zero.

If it is then it means not feeding enough or all is well and being fed more might be ok. Ie. Nutes used up but water remaining is depleted of nutes and diluting the run off.


How much run off are you testing?

Plant in pic looks great. Dont panic!!! :)

 

[growchick421]

Or the meter might being reading zero.

If it is then it means not feeding enough or all is well and being fed more might be ok. Ie. Nutes used up but water remaining is depleted of nutes and diluting the run off.


How much run off are you testing?

Plant in pic looks great. Dont panic!!! :)

I'm getting about a pint of run off. I haven't thought of all the nutes being used. My ppm meter reads down to 12 ppm I have seen,but thought there would be a little trace nutes in run off. I usually feed close to 800ppm and 6.2-6.3 pH. I did notice a little puckering on the leaves but have just recently started watering her every day. This being my first coco she likes the moister medium compared to dryer... over thinking things, it's too late:confused:
Thanks for the like on her. She is a fairly happy plant for a first plant.:happy:

 

[Seamaiden]

I want to say that it is a blue hanna ppm reader. Ill check it in things I have already have checked just to make sure it is still working, which makes me think that it is coming out to high. However my plant is looking green happy and thriving,(pic below).
I have an active air 2way meter by hydro farm to check the moisture level and to give a 2nd reading of pH. Ill try a slurry test too. I need to trans her in the next day or so, so I will probably flush her before I do, still not sure if a strait flush or a low ppm flush would be better :shifty:View attachment 382793

Well she looks pretty fucking good, so I say DON'T go chasing numbers, just log your observations for now, and frankly, I wouldn't change a thing you're doing with her.

Since it's coir you're using, DO NOT use a straight water flush, make it at least 200ppm (.1-.3 EC) or so if you feel you must flush. Personally, I wouldn't.

 

[Coir]

The first thing I would do would be to verify that the meter is indeed working correctly. You can get calibration solution or make your own. 1gm of salt in 500ml of distilled water should read 2000ppm. Another option which I would try first would be to dilute your runoff in half with purified water and see if you can get a reading. This should tell you if you are indeed over the limit of your meter. I highly doubt that you are getting 0ppm in your runoff so it sounds like either your meter is not functioning correctly or your runoff is just too high for your meter to read.
I agree with everyone about your plant looking good so don't try "fixing" anything before you know for sure what is going on with your meter. That said, I have been using Myron L meters for the last 25+ years and although they cost more up front, they will outlast any of the other brands I have ever tried and hold their calibration much better. I would rather spend the money on a great meter once than buy several cheap ones and always wonder if they are working correctly. It will save you a lot of time, frustration, and money in the long run.