Alaskan ice yumbolt47 what do you think?

here are my four babays. 3 yumbolt 47's and one alaskan ice. flowering for 2 weeks

the two in the back are yumbolt 47 (rear left) and alaskan ice (rear right)

The 2 up front are yumbolt 47's

As you can see the two in the back are lookin sick. even more sick in person than on camera. the leaves are more yellow compared to the green leaves of the plants in the front. or is yellow leaves a trait of sativa dominant strains?

I dont think its ph because i've been feeding them all the same water... im figuring either i overwatered them or something with the roots. whats wrong?

400 watt hps
5 gallon grow bags
temp 70 -80

could it be root rot? im using tiger bloom fox farm

i was going to suggest that maybe it was due to the fact that different strains take nutes differently but seeing as both are doing it it makes me think its environmental, maybe the water like you said or air flow try moving the sick ones up front but i doubt its the problem, my best guess is that you have a slight nute buildup in the soil causing the ph to shoot up in the soil, try flushing with water them add half strength nutes

ok thanks. i should i flush immediately or wait till the soil dries.. i watered like two days ago

maybe ur light is to close..and in one of ur pics ur temp said 80 at the bottom of the plant. I'd say keep it cooler like 70

the lights are 16 inches away from all of the plants, but then again you might have a point because the 2 in the rear get more light than the two in the front.

i heard optimum temps were like 70 but i also heard you can get away with 80 degree temps. I just dont understand why the two in the front arent like the rear ones too. but light may be in issue, how far should lights be?

but im really hoping that the alaskan ice gets better. never smoked anything with haze in it nor have i smoked ww and i heard great things about sativa highs. i hate couch lock which is what the yumbolt 47 gives off.

i always thought ak47 was a sativa high but the world of seeds pack says 90 percent indica

if they stay like this... how much will it affect my yield and the potency of my weed?

oh i forgot... one quick question... i heard that you could choose what type of high you get from your plants by chopping them at a certain time.... If i were to chop one of my yumbolt 47 with mostly clear trichs, will i get a heady/uppy/trippy high even tho they are 90percent indica?