New to indoor growing and I’ve got a very sick puppy (one Jack Herer I had up to about 14 in. has already croaked). Is there any hope for this plant and what ails it. Thanks for any and all forthcoming help. 
What is the pH and/or the EC/PPM of your root zone?
And you can also check out this recent discussion we had that also had the plant’s leaves dying:
http://www.ilovegrowingmarijuana.com/community/topic/leaves-dying/#post-29374
Also any relevant info that is asked in the support ticket we might need to know?
http://www.ilovegrowingmarijuana.com/community/topic/fill-out-a-support-ticket/
My wife started the plants on the window sill I don’t recall exactly how long ago and they did great up to about 10 in. I think the one that croaked was a Jack Herer strain and sick pup still lingering is a Cinderella 99. The seed sources was one that’s on a Miracle Grow kick. So she started them in Miracle Grow Starter Mix and was feeding them Miracle Grow at every other hand watering–again as the seed source recommended. When we got the first yellowing and at the tips of the fan leaves I bought a grow tent and moved the plants there…mostly at first because the washroom got to smelling like a skunk den. From the start I suspected the soil mix was hot. When I moved the plants into the tent the Ph was 5.6. I’ve boosted it to the 5.9 - 6.1 range. I have kept a 6 in. fan and 4 in. blower/carbon filter running constantly since. I had a three prong analog soil tester only at the time. When I checked the root zone it showed low to medium nutes and significant under-watering. The leaves just kept on turning yellow and dying. I ran a test tube test on root zone soil next. It showed very high N and P, K, right in the center. After that I started keeping moisture just under the over saturation point trying to flush and cool the nutes somewhat and that is where I am today. I don’t have a TDS meter yet but have ordered one. In the tent I’m running LED’s (2 - 14 watt red, blue, orange, white side lights and a Dirt Genius DGLGL-280 watt multi-spectrum with UV and IR center light 1 yard above the plant top. All the chips in the Dirt Genius are 3 watt. I’m holding temp in the tent at 75 - 77 and humidity at 55%. I’ve 4 more plants just sprouting out in the starter box now. I’ve bought a 4 hole Bubble Boy and am going to go hydro with them. I hope this info will help you help me. Many thanks.
Yup, high nitrogen will do it. It looked like nutrient burn. Flushing as directed in the “dying leaves” link will help.
Looks to me like the plant ran out of moisture for long enough to dry up, and was exposed to heat, and low humidity, and merely dr9ied up. Would not doubt high slat, nutrient levels were a catalyst,