Raising soil pH

Here's the info, there's more pics in my grow log in my sig.

Plant age 56 days since germination. 19th day of 12/12
Indoor
Soil
50% Jungle Growth soil mixed with 25% vermiculite and 25% perlite
Miracle Growth veg nutes with tomato on box (no longer using)
Green Light bloom nutes 12-55-6 (have only used once at 1/2 strength)
Hydrated lime (used sparingly)
Permitherin and Bifenthrin insecticides (for fungus gnats, no longer using)
City water source pH about 7
Lights 13 Cfl's and two 48" t8 tubes (450 actual watts/1650 equivalent watts)
About 42000 lumens for 8 sq ft grow area
79-80F day temp/65F night temp
45% relative humidity average. 65% max. 30% low.
Closet has high CFM exhaust into attic with passive intake at floor level.


Here's my problem. Leaves are pointing down at their tips, new growth appears wrinkled, and the lower leaves are becoming a pale yellow. Some have just died and fell off. The plants are not as vibrant as they once were. My soil runoff is about 6. Too low. I think there may be some N lockout going on, but this is my first grow. I know not of what I speak :)

My question: All I have at my disposal to increase the pH of the soil is Hydrated lime. I have used small amounts in the nute mix before to raise the ph of the mix, but I haven't tried to change the soil ph with it. The plants are not drinking much anymore, the soil is still damp from a watering 4 days ago. Should I correct the pH now or wait until the soil is dry? Should I correct it now and add H2O2 for oxygenation? How should I mix the lime? Should I wait?

Please look at my pics and grow log and help me figure this out. Thanks!

What size pots? Have you transplanted, lately? (roots growing out the bottom?)

Thanks for the reply! The pots are 3 gallon and it's been about a month since they were transplanted to them. Yesterday I cut some additional drain holes at the bottom of the pots and discovered a few roots.

Think they may be rootbound too? I don't have any 5 gallon pots, but I have several 3 Gals. Would cutting the bottom out of the pots and stacking them on top of half filled 3 gal pots work?

Quote:

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Originally Posted by dillhole

Thanks for the reply! The pots are 3 gallon and it's been about a month since they were transplanted to them. Yesterday I cut some additional drain holes at the bottom of the pots and discovered a few roots.

Think they may be rootbound too? I don't have any 5 gallon pots, but I have several 3 Gals. Would cutting the bottom out of the pots and stacking them on top of half filled 3 gal pots work?

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I use 10 inch/(about) 3 gallon pots, too. All the way to harvest. But, I don't transplant into them, until the plants have shown their sex; which is usually 5-15 days into 12/12 flowering. That way, they have fresh soil, for the homestretch run.

I have read about growers stacking pots, but have not tried it.

We will wait until the plant 'Doctor' arrives...:D

I will look at your log, and think on it some more. I don't see an emergency yet, in the pics, here. I don't want to steer you in the wrong direction.

DP is right.....transplant to fresh soil or flush your soil to restore proper ph. Your runoff is low......and is locking out your nutes. This may well be due rootbound issues....your plants look very happy and healthy in the pics and may well simply need bigger pots with fresh soil.

I personally would tell you to go buy 5 gallons pots at wallyworld or something. If you flush and restore proper ph runoff and your plants are still losing leaves.....I'd vote for rootbound.

Fix your ph though.

And if you see roots coming out the bottom......bigger pots asap.

good luck.

Thanks for the quick responses guys/gals. I feel better knowing that veteran growers, such as yourselves, don't see major problems yet.

The low pH I must correct. Like I said I only have hydrated lime. Should I flush them with water about 7.2 or 7.3 or is that too high?

One thing that concerns me about watering now is that the soil is still damp. I have very good drainage, the plants just aren't drinking much. I don't want to overwater and run the risk of root rot.

In an attempt to kill fungus gnats, I covered the top of the soil with perlite and vermiculite. After that is when the plants seemed to quit drinking. Could the vermiculite be trapping the moisture, keeping the soil from breathing? Should I scoop it off?

Yeah, I know. I'm the new guy with a million questions;)

I think your issue is twofold and by transplanting you can solve both issues at the same time.

Yes, you have to worry about root rot. But your ph being off is more of an issue than root rot you don't have yet. I love a good root product like Cannazym that prevents root rot and Rhizotonic with helps TREAT root rot. Consider one for your plants and growing. I'm wondering if you can add H202 to your flushing but am not really sure in soil so hesitate to tell you to add it. Something to think about though.

If you have done something different to your plants and then see a change for the worse by all means fix it. Remove the stuff and see what happens. Plants do things for a reason.....they don't just decide one day to get root rot or act funny.....they respond to their enviroment. If your roots are coming out the bottom then yes, these things can happen. You can get root rot. Your ph will drop. Your plant will not grow well and becomes at risk for all sorts of diseases, molds etc. If you cant get ahold of larger pots such as 5 gallon and get your girls transplanted in the next day or two (tops!!!) then I'd go ahead and flush with water ph'd to 6.9 until you get your desired runoff. It may take several gallons so I do mine in the bathtub.

Your questions are fine....they are thought out and reflect your willingness to do the work required to grow good plants. It's all a learning thing......but those who teach love to teach to those who listen and learn. I have a feeling you are capable of both. :)

Thank you for the kind words. You are very encouraging!

I've already scoured my little pissant town for 5 gal pots and there are none. They must be a seasonal item. In fact, i had to order the 3 gal pots online. Wally World has some large decorative pots that are very expensive and they all have the built in drip tray. I'm short on money and time so I think I'm gonna try to stack some 3 gal pots. I think Shovelhandle has a thread where he did this and it worked.

I'm gonna add Cannazym to my list for next grow, thanks.

I'll keep ya posted :thumbsup:

Cool beans....!!

If you have feed stores anywhere around you you can grab some pretty big sized feed tubs and drill holes in the bottom for drainage. I would totally go with your "stacking" suggestion if you can accomplish it (though I'm not sure how...but worth a try) vs flushing a rootbound plant and leaving it in the same situation it was in already.