Leaves took a turn for the worse.

Ok, here goes. I will try to include everything that may be of help, if I neglect something let me know, this is my first time growing and I am far from a green thumb. Until recently the plants looked great and all information to date has been obtained from this site, so thank you all.

To begin with, seeds were planted on July 15th and were under 24/7 light until roughly a week ago at which point I switched them to 18/6. Temperature inside the cabinet is usually right around 80 degrees. It hit 90 right before the pictures seen below were taken due to a fan burning out; this issue has since been fixed.

The issues with the leaves also just started when I transplanted about 2 weeks ago. The crunchy leaves at the bottom happened almost immediately, while the yellowing is recent. I figured the crunchy, shriveled leaves were due to transplant shock, I could be very wrong. I also thought I had purchased nice soil; though now through further reading realize I may be wrong again as it includes peat moss. They are currently in 8 inch pots and will be transferred to 12 inch pots before flowering.

Set up details:

Lights: 5 fluorescents and 4 cfls
Fertilizers used: started with miracle grow, switched to Fox Farm Grow Big after a few weeks. I will switch again to Fox Farm Big Bloom when flowering.
Soil: started with Hyponex, switched to Black Gold Organic when I transplanted 2 weeks ago. (soil includes: peat moss (I know), compost, earthworm castings, forest humis, perlite and pumice)

I added lime yesterday because my best guess was low Ph leading to nutrient lockout, though as I said, I only know what I have read here and it was my best guess. Any help you can offer would be greatly appreciated. Hopefully they can be saved and if so do you have any ideas on how much longer I should leave them in veg growth phase? Thank you in advance for your help.

You've gotta run out and get a pH test kit NOW and do a runoff test. That isn't good.
Also I am seeing that looks like pots with built-in drip trays? Rip those off and I'll bet it's wet under- tip the plants out of the pots and I'll bet the bottom couple inches are totally waterlogged.
You need excellent drainage growing a fast-growing plant like cannabis indoors, adn that type of pot doesn't provide it.

I have a Ph tester for my spa, I will see what it comes out to tonight. When I water them I tip them to let out the excess so that it is not sitting in standing water. I also use a water meter and it never says wet, just moist or dry. My larger pots do not have the same attached drip pan so maybe I will transplant when i get home tonight along with putting river rock in the bottom. Does it seem like it may be be low Ph locking out nutrients and if so will the lime I added last night bring it up?

Aside from checking the Ph, is there anything that can be done to help them along? Is the yellowing nitrogen or magnesium deficiency? Meaning should I spray the leaves, add epsom salts, etc.?

Find out your ph first....if it's off it doesn't matter what you do to it....fix the ph.

Not to be mean...but i've heard several people say the same thing as you did and I'm curious....why would you not test the ph before assuming it was low and why not test the ph of what you are adding....especially since you have access to some sort of ph tester.

Again...I apologize if I sound mean or rude; it's just that I've seen several people do that kind of thing and am curious as to why you'd approach it like that. :)

Not taken as rude at all. I am new to this and until recently was unaware of Ph and it's ability to cause so many problems. I previously (until about 1-2 weeks ago) had them planted in different soil and there were no problems at all. Once I transfered to the new soil the problems began. I then read a few posts about peat moss and it causing low Ph (i.e. it is at 4.5 or so) and thus figured that since I had no previous problems my water was fine, Ph wise, and related it to the peat moss. I found another post stating that lime will help bring Ph up to about 7, being very close to optimal range and figured I would add the lime, hence fixing the Ph. No testing needed. I am obviously wrong and will test the Ph when I get home today. If it is still low, which I assume it will be as it has only been one day I will try to fix things from there. I am just unsure of whether or not the lime will help fix this or if I need to lose the soil (Black Gold) and revert to another type of dirt, Fox Farm is not available near me. Then on top of it, if the soil balances out I am still at a loss as to what the issue is with the plants, hence unable to fix them. Thanks for the reply, I will keep you posted and any further information would be greatly appreciated.

I'm not a soil grower but Stinky will be back I'm sure to answer the soil qs.....phwise...yes, always check because there could be things in your water that react with certain soils etc...and send your ph in weird directions.....and it could be the opposite of what you think. Your ph could be high already (maybe your water has high ph or....?) and then lime on top of it.....now higher ph.....plant cannot take in nutrients at incorrect ph so that's why foliar feeding or adding more things won't help (and may even hurt) before you fix any ph issues.

Definitely makes sense. I don't think it is high already due to the peat moss only suitable to lowering it, but I will check it later today none-the-less. I figured I can check it then transplant them into the larger pots as Stinky mentioned the ones I have being no good anyway. Hopefully that will make sure I don't over water as I just watered them and will have to again to obtain the run off. So, if they are still standing when I see them next we will take it from there. I will await Stinky's input on the soil issues and post Ph tomorrow. Thanks for the help.

Even tipping the water out, there simply isn't the air flow you need to dry out the bottoms.
Low pH issues are compounded by extreme wetness.
River rock is unnecessary.
Repot, use a soil with plenty of perlite, and when you do, check to see how soggy it was in there! Trust me, my local grow buddy was using those too and almost lost her mothers- when she gave them to me for doctor services, they were sitting in an inch of water inside the pot.

Ok, so obviously lose the current soil (Black Gold) that I am using. Should I go back to Hyponex, with lots of Perlite. Is there anything wrong with that soil. I switched because I figured organic was better, but I have a bag I can go back to.

It may be that I had a bad batch---if 200lbs is considered just a batch---but the hyponex that I bought gave me nothing but grief. It needed tons of sand, perlite and lots of working to salvage it. Still I'd never use it again. That's just my opinion. I'm using B'Cuzz coco now. But thats a whole 'nother ball of wax, so to speak.

Anything but Hyponex for me---anything.

Black Gold is probably fine. Add more perlite to it on the next repot.

IT IS NOT THE DIRT, IT IS THE POTS!!!!!!!!!!

Until you fix those, there's no point in discussing anything else!

I changed the pots the day you told me to. They are now in 3 gallon pots with detached drainage dishes. Though FYI, there was no standing water or mud at the bottom of the previous pots like expected, the dirt looked nice.

I decided to split the difference in regards to soil and used a 70% Hyponex, 30% Blacks Gold and lots and lots of Perlite for the re-pot. The transplant over all went pretty well, they are now recovering from their shock and leaving the doors open lowered the temp to 80 degrees, making them happier, my upside down canoe leaves seem to be disappearing.

The yellowing leaves (still wondering if its magnesium issue), as seen in the original picture above are obviously still there, though new growth is strong and a nice green. I am waiting to see if it is spreading. It is the bottom leaves of both plants now, but only one or two nodes up, the next 7 or so are fine. Maybe the Ph is leveling out as I did put some lime in the soil as well.

I also cut back the FoxFarm liquid fert to half strength for grins, trying to avoid nute burn. I FIM'ed a week ago and have yet to see new tops forming, I have debated putting them into flowering anyway, though not sure they are mature enough , there are no alternating nodes as of yet. Just worried as the largest plant is now almost a foot and a half tall and I don't want to run out of room during flowering, if they make it that far. :)

Thank you for continuing to watch the post.

Nice.
Watch the new growth as you are doing, and monitor the old growht for damage spreading- which I'll bet it won't.
You are doing everything right now! Cheers!

Thank you Stinky. Do you have a recommendation on flowering? Like if alternating nodes are not showing yet will it be harmful to start (or) since I FIMed a week ago, do I need to wait for new growth to start before flowering or does it not really matter? Or you can just tell me that it is more beneficial for me to attach new pictures on Monday and wait for an answer from you then. Sorry for the poorly typed post, its Friday.

lol no you don't have to wait to attach pics.
After you FIM, pinch, or prune in any way, it is best to wait at least 2, but ideally 3, weeks before initiating the flower cycle. You're right about waiting to see new growth.
Not every single plant of every single strain will even show alternating nodes (most but not all do). The 3 weeks after pinching that you are going to allow should be plenty of time to let the plant finish maturing.

Thank you very much, looks like I can start to flower on September 21st then. Very much looking forward to it. I will post again (hopefully not with plant issues) to update status. Have a good weekend.

You too, looking forward to the weekend and some pics! :D

Glad to see your makin the girls happy! Stinky is a genius isn't she?! I always pay attention to her posts.