hello all and thanks in advance for any info!! 1st off i know i need to get some pics up and will soon, but thought i would see what i get without them 1st. 2x4 tent 400 switchable MH/HPS vented. small 4x4 square pots. humidifier and heater for colder nights when lights are off. FFLW and FFLW 50/50. ph at 1st tested with drop kit, just got a hanna meter last week!! ok lets get started... i dropped a bunch on money on this and had bad luck thus far. I am on my 2 batch trying to get this nailed. 1st batch started out fine and looked great until about the 3rd set of true leaves. then the tips started to yellow/white and progress down the leaves. basically over time as you know they dry and die. i have some from my 1st batch that are stunned at about the 4th node. i have tried every thing i have read about and could think of. now i have 6 new ones that just started to breach. purple sour diesel and white russian D. oh and one bag seed just for kicks. 1st batch mostly trashed now. used tap water that set out for a day or so. watered with PH drop kit showing 6.5 (which after i got my meter the same measurement on meter was 7.2). WTF seems a lil inaccurate to me...lol the drops that is. 2nd batch again started out great till the 2nd leaves started to show and the yellowing came back..WTF. some are about dried up and dead. 1st couple of waters on 2nd batch was tap, but then switch to distilled. PH is exact with meter at 6.5 to 6.8. still no change!! and calibrated it everytime for the 1st couple waters to make sure it was still accurate. so....i shut off the HID lamp and got 3 100 CFLs for start this 3rd batch on and see if the light was the cause. I started out having lamp about 24inches with MH bulb, then moved up even higher thinking it was too close. nada, no changes!!! thought i over watered so let soil dry out a good bit. no nutes at all on 2nd batch. on 1st batch watered once with 1/4 nutes, but only after issue started. kinda troubleshooting i guess but that just burned them even more. guess thats the geek in me to start a process of elimination. that has not proved to work in this element. ;-) any input would be great and yes i know i need to put up some pics and will when i find time. being in the IT field and working a lot along with this issue is rather time consuming!! again thanks to all that may help!! sincerely utterly frustrate newbie!!!