Should I re-water wet soil to correct PH?

[mb2183]

Hi all. I've been lurking here forever and have learned a huge amount from you all over the past year. Thank you so much for all the wisdom! I find that I have a question that may be somewhat novel as it is not covered in any stickies or guides, and I can not find it with a search (though maybe this is just dim-witted user error? But please know that I really tried to find this answer on my own before posting.)

Quick version: 3 days ago I watered newly transplanted clones with water that turned out to have very high PH (7.7) I just found this out with my new testing pen. The plants are spotting and not really growing. I'm sure this is a PH issue. Should I re water the plants now with PH adjusted water (even though the soil is still soaking wet?) or do I need to wait until it dries out and is ready for the next watering?

I'm happy to provide specifics about my grow, but am hoping this is a concept that can apply more broadly? Thank you very much in advance for any help or advice!

 

[MrGhettoGrower]

You just transplanted from what 18oz cups to 5 gallon pot?
Hows the plants look? If they look good and perky I wouldn't
water till good and dry. Are you sure your pen is calibrated and
accurate?

 

[mb2183]

Thank you for the quick reply! I should have given more detail:

Transplanted 6 fully rooted (in rockwool) white widow clones into 1gal pots of MJR Organic soil. I just put the rockwool on top of some mycorrhizae in a hole in the soil and watered. The plants are about 6" tall and on 3rd/4th sets of leaves.

The plants are relatively perky, but have some downward curling and some are starting to show yellow/brown spots. New growth is slow and pale (and in some cases a bit twisted.)

Setup is in a DR120 tent (4x4x7) under a 600W MH aircooled by a 6" vortex fan. Temps are 73-77 all the time. Humidity at 45-55%. Currently running 24/0 light cycle. Have a small oscillating fan blowing on the girls.

Pen is brand new and was calibrated the day of the water testing by my local grow shop, so I'm fairly certain it's accurate...

I can go take pictures if you think I'm off base about the PH? Just seems that is the first thing people go to, and I know I gave it some bad water..

Thanks again!

 

[mb2183]

I figure I'd give an update on what I've decided after collecting a lot of opinions and doing a crap-ton of reading. Hopefully this might help someone facing similar problems in the future.


I think I actually had a few problems. One was/is certainly the ph, but I think it's not so much in the soil (as I'm using organics which should help buffer) but rather in the rockwool mass that I planted. My hope is that as the root mass develops out into the soil it will stabilize and find the nutes it needs for now.


Which leads to problem number 2: even if the ph was right I'd probably still have an issue because I didn't nute the first feeding at all. Since the roots were initially in the rockwool they could not feed off the soil. So I starved them, too.


Problem 3 was that I had the hid light too close to them (at about 1.5ft for my 600w mh). Given that they had a minimal root structure to feed with and were likely under a less intense light when they were taken as cuttings, I added more stress and stunted/bleached new growth.


So i am actually not going to do much at this point but wait and hope they develop a robust root structure and then resume normal growth. I have been manually aerating the pots as much as possible with a fork to help dry it out more quickly so I can promote root growth and fix the ph on the next water more quickly. Also moved the light a good deal higher up and hope to see some darker green return.


I'd be interested if people think I'm way off here? Thanks again for all the help so far! You are all amazing and there's no way I'd even be attempting this without you.

 

[unohu69]

You know what I like about this thread? You posted a question, then continued to research the problem on your own instead of waiting for instructions on how to grow. Nice job. I actually like your conclusions, I always allow a day or two for a plant to get over being transplanted.

 

[jojo2002]

Sounds like you already know what to do, only thing i would do is maybe go 20/4 or 18/6.

 

[cactusbudz]

what kind of water are you using? ro, distilled etc.....because by the brown spots (like rust spots) sounds like manganese def which is common in ro water if your not using cal mag

 

[unohu69]

I really like 18/6 (havnt tried 20/4). I had one plant in a pc case 18/6, and two others of the same strain in a 24 hr box. it seemed to me that the 18/6 plant starrted showing flowers sooner than the 24 hr box after they were all switched to 12/12. so maybe the shot dark cycle helps the plant recognized the switch faster IDK. just an observation.

 

[mb2183]

Thank you for the replies!

The last water was just bottled spring water that I didn't ph adjust. I'm sure the plants are deficient in mg (as well as others) and I'm hoping they will self correct a bit when the roots grow out more. I may give a bit of light nutes in the next watering but only over the very center of the pot where the rockwool was planted. Gotta feed those roots, too!

I know the debate rages on about veg light cycles, but I subscribe to the Jorge Cervantes / plant biology line of reasoning that cannabis does not need a dark cycle to grow but rather flourishes in constant light. The added benefits may not be worth it economically when considering additional electricity cost, but I just have a small grow for my own use and like to grow it like this. I do wonder, though, if these clones were under something different before I got them and are maybe feeling a bit of the shock of that too? (oh how the mistakes pile up! Live and learn...)

 

[cactusbudz]

right on mb. goodluck on your grow

 

[cowboylogic]

Jorge is correct that cannabis is a c(3)annual and does not really need a dark period. But most any plant will benefit from a dark period. I like 20/4 myself and having done 24/0 in the past I do not see any real difference in growth rates. But plants under 20/4 seem happier overall....

 

[mb2183]

Interesting. Thank you, cowboy. Does it harm/shock them to go from 24/0 to 20/4? What about vice versa? Thanks!

 

[cowboylogic]

Interesting. Thank you, cowboy. Does it harm/shock them to go from 24/0 to 20/4? What about vice versa? Thanks!

YOUR WELCOME. Its not so much about the single drastic changes we make in light cycles Its more about being constant once a choice is made . Also you cant really change your mediums pH by simply running pHed water through it. You are growing in soil so dont get all caught up in the pH game. Yes a mediums pH is important to a plants growth. But the pH at which you feed means little. Changing a mediums pH takes time. And accurately changing a mediums pH not only takes time but also takes considerable pratical knowledge. Most of us are growing in 3-5gals of dirt. What we start with at the beginning of the grow is pretty much what we have to deal with during the grow. Making a pH adjustment in such a small mass during a grow can be a challenge for even the most seasoned grower.

 

[Jack Harer]

It's a whole lot easier to raise pH than lower it. How are you testing the pH. It's the pH of the actual SOIL you're concerned with, not what goes in or comes out. There is a tutorial on how to get the soils pH in my journal. If you do have a high pH, adding some "Flowers of Sulfur" or elemental sulphur will lower it, just take it in baby steps. Aluminum sulphate will work, but be aware that aluminum is toxic above certain levels.
pH should rarely be an issue in soil. It would have to be REALLY out of whack to get a lock out. Most of the time when a lock out does happen, it's an over abundance of one nutrient that locks out another. Nutrition is a delicate balance.

 

[MrGhettoGrower]

You still haven't post a pic? you'll get better responses and it easier to a respond with a pic~

 

[asaph]

if you see serious symptoms you can water again, overwatering is over long periods of time and not just from two waterings too close apart.

of course, the closer the extra watering to the first or to its original schedule the better.

 

[DimeBagBrewer]

YOUR WELCOME. Its not so much about the single drastic changes we make in light cycles Its more about being constant once a choice is made . Also you cant really change your mediums pH by simply running pHed water through it. You are growing in soil so dont get all caught up in the pH game. Yes a mediums pH is important to a plants growth. But the pH at which you feed means little. Changing a mediums pH takes time. And accurately changing a mediums pH not only takes time but also takes considerable pratical knowledge. Most of us are growing in 3-5gals of dirt. What we start with at the beginning of the grow is pretty much what we have to deal with during the grow. Making a pH adjustment in such a small mass during a grow can be a challenge for even the most seasoned grower.

Hey Cowboy, great to see you back, I read that you had died over at riddlem3, I guess that was bogus huh ?

 

[asaph]

Jorge is correct that cannabis is a c(3)annual and does not really need a dark period. But most any plant will benefit from a dark period. I like 20/4 myself and having done 24/0 in the past I do not see any real difference in growth rates. But plants under 20/4 seem happier overall....

I saw data from a research that showed 20/4 the most effective schedule in terms of growth and future yield. more than 24/0 and more than 18/6.

20/4 produced the sturdiest growth and the most bulk. Best final yield, taken as 100%
22/2 Less of both growth and bulk. Yield 88%
18/6 Sturdier than 22/2 but slightly less bulk. Yield 87%
24/0 Much lighter in all aspects than 18/6. Yield 79%
16/8 The weediest plants. Yield 67%