a plethora of problems

It's my first grow and I've got 2 plants, both from bag seeds, about 3 weeks old. My grow box is 12" wide 36" long and 38" high with 2 100w CFL's that I leave about 3 inches from the plants, on 24 hours a day. I have two 12v computer fans, one set up for intake, the other for exhaust, and the exhaust has a home made carbon filter on it. The plants are in half gallon pots filled with a mixture of about 3/5 potting soil, 1/5 regular soil, and 1/5 sand. I water them every 1-2 days or as the top soil dries out, and I mist them 3-5 times a day with water. In the past 2-3 days I've started misting them with a very very low concentration of Miracle Grow.

The problems:

1) Drooping. The leaves started drooping about 1 or 1.5 weeks ago, but I am almost 100% positive it is not from overwatering, as I only water the plants when the soil dries out, and make sure that no more that 3 or 4 drops of water come out of the bottoms of the pots when I do water.

2) Yellowing. The first 2 leaves, the oldest, started yellowing about 5 days ago, and are now very very yellow and dry. The leaves become greener progressing up the plants, which are about 4.5" tall. It's possible that it could be a nitrogen deficiency, which is why I started misiting them with the Miracle Grow, but the descrition and photos on the FAQ don't exactly match what's going on.

3) Curling. The middle leaves began curling down 3-4 days ago.

4) Spots. The spots began as white, and some have turned brown. They are only on the lower 2 yellow leaves. I inspected thoroughly for spider mites or other bugs and found no evidence.

I'm worried about the little girls as they were just starting to get cute and give off that nice natural smell. Any help would be greatly appreciated.

I WILL ATTATCH PHOTOS SOON

I also just bought a light timer, I was thinking about switching them over to 18-6 because I heard 24-0 might be too much. Can I just go ahead and switch em or should I wean them with like a day at 23-1, then 22-2 etc.? Should I even be switching them?

Photos are of both plants, an example of the curling, and of the spots. I'd like to reiterate that I am SURE there are no spider mites.

1) To counteract the drooping you should not water for at least a day or two then water to where A LOT more than 3 or 4 drops come out the bottom. That just means you have good drainage and will prevent water build up and ultimately root rot.

2) This is more than likely a Nitrogen deficiency and can be easily fixed by using any plant food with a good amount of Nitrogen. When buying plant food Nitrogen is always the first of the 3 numbers:

N-P-K = Nitrogen, Phosphorus, Potassium

Using a foliar spray (misting) isn't really your best course of action. Try incorporating it into your water when you feed. Bone Meal and Blood Meal are a great organic way of feeding your plant the proper nutrients and can be found just about anywhere.

3) This is probably a Phosphorsus deficiency and can be solved by following the same steps in 2.

4) This is probably your worst problem (in my opinion).. This is a problem of PH. You need to get a PH read of your soil then begin PHing your water with PH up and PH down to 6-7. As long as its not too far off from there, you should be good. This could also be from nutrient lock-up (which occurs when you feed your plant an overload of nutrients and requires you to flush the soil with PHed distilled water and allowing at least 50% run off), but I doubt that's the case here. PH is one of the most important elements of growing because your plant needs the optimum PH (6-7) to be able to use all the available nutrients properly.

Honestly.. If I were you I would start over with a new plant, but I don't know how much you have invested in this one. You can still save her. Growing is all about trial and error and learning from your mistakes. Well, I hope that helps man.. Good luck!

whats your medium?
whats the humidity like. it almost looks like mold spots. are you sure you have good air movement with those small fans. what temp do you keep the box at?
from experience and from outsider opinion, 24 hours on is not all that great. go to 18/6! someone said to me and it makes sense, humans need rest and so do plants. think about it it makes sense. as soon as i came off 24 hours i seen a big difference.
i had also used miracle grow also and i would just suggest to steer away from that kind of nutes and look into something from a hydro shop. a month and a half into my grow i started using the fox farm nutes and soluble. huge huge huge difference.
fill in the info and ill see if i can help.
oh and also are you balancing the ph of your water?? tap or distilled??
how often are you watering?
what kind of dirt is under the top part of the potting stuff?
how old are these??

Also, that is a good idea to switch them over to 18-6. You don't need to ween them at all.

whats your medium?
whats the humidity like. it almost looks like mold spots. are you sure you have good air movement with those small fans. what temp do you keep the box at?
from experience and from outsider opinion, 24 hours on is not all that great. go to 18/6! someone said to me and it makes sense, humans need rest and so do plants. think about it it makes sense. as soon as i came off 24 hours i seen a big difference.
i had also used miracle grow also and i would just suggest to steer away from that kind of nutes and look into something from a hydro shop. a month and a half into my grow i started using the fox farm nutes and soluble. huge huge huge difference.
fill in the info and ill see if i can help.
oh and also are you balancing the ph of your water?? tap or distilled??
how often are you watering?
what kind of dirt is under the top part of the potting stuff?
how old are these??

just put them on 18/6 because too much light stresses some strains. Don't water for a few days. water them with miracle gro if there is no fertilizer in your soil, otherwise don't. Don't foliar spray miracle grow, get something like VF-11. Try adding some superthrive to your watering mix to drop the pH a little bit. Sand isn't that great for weed it makes a very heavy mix.

Seeing as this is my first grow I'm not incredibly concerned with yield quality or quantity, but more with knowing what to look out for and how to keep everything running smoothly next time. That being said I'm going to try and salvage these by switching to 18-6, a watering solution with more NPK, and tomorrow I'm going to grab some pH test strips and pH up/down. Thanks for all the advice. Any other observations about what I've said or advice about how to proceed?

I tested the soil and it came out to be somewhere between 6 and 6.5. I am now thoroughly confused.