My lowryders are sick (PICS)

lowryder #2
six weeks old tomorrow (harvesting 2-3 weeks from now?)
250w HPS
fox farm ocean forest soil

temps are 80-85 during the day, low 60s at night.

i'm wondering if this problem might be related to ph. i just recently got a test kit and found out that the water they had for their first three weeks was about an 8!! and the water I switched them to was at 5! so i FINALLY got the ph of my water in check at 6.3.

on thursday i watered and fed them with fox farm big bloom. this was the first time they got water with a decent ph level. they hadn't had any nutes for about a week and a half, and even then it was tiger bloom at quarter strength and big bloom at half. the day after i fed and watered, this is what a couple of my plants started to do.





this is only happening on the older leaves. the buds are still looking good and growing well:



and this plant has pretty much always had an issue with the tips of the leaves yellowing, any ideas?



please give me some feedback!

try to get your temp around to 74. 80+ is little high

I'm working on getting my temps closer to 75-80. the past couple of days have been at about 80. I'm going to upgrade my fan soon hopefully that'll help too.

here are some more pics:

come on, anyone else???

it might be nute burn,,,lowryders dont need much feeding,,,,or it could be nute lock,due to salt build up coz of high ph,,,,,id flush them well now with ph'd water.peace

um dude as for you leaves lower the temp of the plants start watering with cool water not room temp... harvest when 90% of the pistil turn brown..

Well, temp is not too high, over 90f is high if you dont have good ventilation!, but if yu think that way these plants ( ganja ) see 80-100f in natural enviroment........
and that looks very clear nute burn or PH problem!

your temp has nothing to do with it, its nute burn. Get your PH straight(6.5 in soil iI like) you said you plan on harvesting in 2 weeks, then that gives you plenty of time to flush your plant with 2.5 to 3 times the soil in your pots w/ water. so if your using 1 gal pot flush with 3 etc... then immediatly feed at 1/4 strength. I did this and it got my last crop healthy again. I am telling you this will get you straight, but dont water again till they dry up a bit. You could even give one more good feeding b/f you start to flush for the pre harvest. GL