Problems with soil grow

Hello there!
I have a friend that now has 2 females (not sure the strain) in soil. They are showing some problems and one of them had a light fall on it and stay there for quite a bit and burn it. It has been a month from then (the right plant in the pictures) and it looks like it is soon going to die. The other has it's lower leaf yellowing. I will ask him what exactly he has been giving them but I think it would be a deficiency of some kind... Is there anything he could do to help them?
Here are some pics:


Thanks in advance!

Need to know what his soil mix is and what/how much they have been fed. Possible cal/mag issues but difficult to see in pics.

Well he said he used normal soil mixed with plant fertilizer from the gardening shop. He also added an all-purpose flowering supplement. He said that due to signs of overwatering he might have underwatered them a bit. Now they have more water so maybe that would help a bit...

looks like he overfed it. ferts like mg and jacks give rates for outdoor grows. for indoor grows you must reduce the rate by half. the one plant has claw and is indicative of too much nitrogen.

yea I agree with dannyboy, over dose!! the soil may not be top quality either, looks a little compact an has hardly any perlite. maybe a better soil would help.

The plant on the right is over watered.
The one on the left probably got the same amount of water, but is handling it ok.
When you over water you keep oxygen from getting to the roots. that can cause a lock out of nutrients.
remember to lift the container, when the container is light in weight water, don't water on a schedule, only water when the plant needs it.
Marijuana is a semi-arid plant it doesn't need a lot of water at one time.

IMO- your friend is killing his plants with love.
Let the soil dry out some, check your soils pH

IMO- buy some Cal/Mag give it to your plants once a month as a preventative measure.
about 70% of plant problems are Cal/Mag issues.

Good Luck on Your Grow.

Top fuel said it best man I would take that and run with it.

Thanks a lot to everyone I've passed the advice and hopefully they will get better!