Grow Mediums Runoff pH question

[Mañ'O'Green]

What is your medium? Is your plant starting to flower in earnest?

 

[Bob's Auto's]

I think our (solocup growers in coco I mean) problem lies with watering them cups. On one hand you want the medium to stay wet enough so the plants stay in continuous growth, but on the other hand if the medium stays to wet the pH in the root zone gets out of whack.
So it's a fine line we have to walk on I guess...But that's probably why it's called a Solocup contest

 

[DCLXVI]

What is your medium? Is your plant starting to flower in earnest?

Hi Man O, thanks for checking in.

Coco coir, Cyco brand 70/30 perlite mixed in. Flowering right on time and looking pretty well overall. I'm not seeing any major issues. I was just tracking input and outflow ppm and pH to see what was happening. Noticed a significant pH drop.

It could be how I measure. I notice that if I put the pH pen into the runoff it initially reads 5.5-ish but if I let it sit a few minutes it drops to the mid 4's slowly. It could just be unstable runoff and I do realize checking runoff is not reliable. Mostly tracking ppm/EC to ensure there isn't a salt buildup. From what I've read this is important in coco but not so much pH.

Just curious if it actually needs to be addressed more aggressively or if it's a non-issue.



Plant pics: Day 41 There are a couple yellow boogered up leaves towards the bottom

 

[DCLXVI]

Shoot, I forgot these pics may be helpful as well. Looks ok other than a few older leaves towards the bottom?

 

[Del boy]

Shoot, I forgot these pics may be helpful as well. Looks ok other than a few older leaves towards the bottom?

View attachment 1403953



View attachment 1403954

They look very nice :smoking:

 

[Mañ'O'Green]

Hi Man O, thanks for checking in.

Coco coir, Cyco brand 70/30 perlite mixed in. Flowering right on time and looking pretty well overall. I'm not seeing any major issues. I was just tracking input and outflow ppm and pH to see what was happening. Noticed a significant pH drop.

It could be how I measure. I notice that if I put the pH pen into the runoff it initially reads 5.5-ish but if I let it sit a few minutes it drops to the mid 4's slowly. It could just be unstable runoff and I do realize checking runoff is not reliable. Mostly tracking ppm/EC to ensure there isn't a salt buildup. From what I've read this is important in coco but not so much pH.

Just curious if it actually needs to be addressed more aggressively or if it's a non-issue.



Plant pics: Day 41 There are a couple yellow boogered up leaves towards the bottom

View attachment 1403944



View attachment 1403945

I could have almost guessed the look of your plant by the drop in PH in your pot. When the plant goes into flower (full on) the roots of the plant will exude substances that will drop the PH in the root zone. this in turn will signal the microbes to make more P-K available to the plant. It is obvious in a small container like a solo cup and shows quite dramatically in DWC. It is a signal to you to up the P-K a bit. Do not chase PH. Just fertigate at the 5.8 PH that you should be using. Steady as she goes.

By the way this is one of the reasons I do not like using run-off for anything. Too many things going on in the pot. I may change my tune on this next year after some new classes. Time will tell.

 

[Lil Dab]

I could have almost guessed the look of your plant by the drop in PH in your pot. When the plant goes into flower (full on) the roots of the plant will exude substances that will drop the PH in the root zone. this in turn will signal the microbes to make more P-K available to the plant. It is obvious in a small container like a solo cup and shows quite dramatically in DWC. It is a signal to you to up the P-K a bit. Do not chase PH. Just fertigate at the 5.8 PH that you should be using. Steady as she goes.

By the way this is one of the reasons I do not like using run-off for anything. Too many things going on in the pot. I may change my tune on this next year after some new classes. Time will tell.

Hey @Mañ'O'Green Not trying to steal thread but I have been reading about runnoff ph.So I am curious as to way my ph would be raising the closer I get to flower? I am not chasing it just monitoring as with the ec/ppm. Once a week I give it some extra water which does bring the runoff ph down. Always in at 5.8-5.9. Coco perlite 70/30. Plant seems fine so I haven’t done anything drastic just been doing some reading about it.

 

[Mañ'O'Green]

Hey @Mañ'O'Green Not trying to steal thread but I have been reading about runnoff ph.So I am curious as to way my ph would be raising the closer I get to flower? I am not chasing it just monitoring as with the ec/ppm. Once a week I give it some extra water which does bring the runoff ph down. Always in at 5.8-5.9. Coco perlite 70/30. Plant seems fine so I haven’t done anything drastic just been doing some reading about it.

Never just water coco. If you are fertigating to 20% run-off by the end of the water day you should never need to flush and the pot will take care of itself. There is just too much going on in the pot to make a guess.

 

[Lil Dab]

Never just water coco. If you are fertigating to 20% run-off by the end of the water day you should never need to flush and the pot will take care of itself. There is just too much going on in the pot to make a guess.

Sorry @Mañ'O'Green I guess i just missed worded that. I have not "just watered" coco at all this grow. i always use my MC 1part 3g epsom salt .5g calmag 150 ppm. And always fertigate to 20% runoff minimum when i do. what i meant was i give a extra liter or two once a week and runoff ph comes down but still no where near 5.85 i go in at. most days my runoff ph is 6.2 or higher. runoff ppm is always at least 200 lower then the in ppms.

 

[DCLXVI]

Thanks for the input everyone. I really appreciate you all taking the time to read and reply.

@Daledenton84 - if your coco was buffered from the factory the pH may hold high until the initial chemicals are washed out. Mine certainly dropped at after a point. Track it for an idea of what's happening and what direction its's going.