White Dwarf Auto/fem issues, arrggg!

My wife has MS and we were made aware that using medical marijuana would help her. Boy does it... but we were obtaining it through illicit means, which we had a problem with. So.... we decided to grow our own, contacted a facility that sells med. seeds and purchased 5 white Dwarf auto fems, and 5 Red Dwarf auto fems. I have grown 2 whites now and 1 red. The red did really well, but both whites have had the leaves turn yellow prematurely. I am wondering if this is common with this strain or am I doing something with this strain that I shouldn't. I am growing in a neutral soil and using Advanced Nutrients Hobbyist Combo pack, and following their schedule. I grew 1 white first, then after harvest, started the 1 red and 1 white. The 1st whites leaves started to turn at about 28 to 30 days, although it did produce some nice bud for my wife. It was not tight or dense but none the less still good she said. Now the 2nd 1 is doing the same thing at about the same time. I have heard that they are nutrient sensitive, so any info that I can get would be greatly appreciated, thanks in advance.

If a plant becomes root bound, no more room for roots to grow inside the pot, most plants leaves will start to droop and leaves will start yellowing from the bottom up. Are you currently giving them any nutrients? Have you noticed any slow growth lately?

Yellow leafs from the bottom up usualy means lack nitrogen.
(I always start mine Bout 3-4 weeks old I start 1/2 strength Chem Nutes every other watering.)
Most Autos don't need much ferts some do. Go easy!!

Keep the soil moist but not mud.
Overwatering is easy error on the dry side.

Start your autos in 2 gal containers to get max yield.
Transplanting can cause delay in growth an hurt yield.

Keep the cfls close as you can without burning em.
An add more light as you can to get better buds.

Love that red dwarf!

Yeah, that Red Dwarf is a beautiful plant. Stunning in fact... at least I think so anyway. I have heard that the white does not like a lot of nutes. next one I will go with 1/2 strenght recomended by Advanced.