Leaves Dieing Fast HELP

What is wrong the leaves dry out and curl all up with spots on them. The temps varies between 85-78 degrees with humidity level at 47-50%. There in Miracle Grow there under a 600W HPS with 18/6. I feed,water,feed,water. When feed I feed it CalMag+ and some cheap 20-20-20 nutes i got off ebay at 1/6 the recommended dose. My ppm after adding nutes is 450. I just purchase some Advanced Nutrients Sensi Bloom A&B so I dont have to use the cheap 20-20-20 nutes any more. I have some sunshine Mix #4 to transplant them into when I start flowering. The pH is around 6.0-7.0 I never know the exact number because I have the pH 3 drop solution ph kit. What am I doing wrong?

Salt build up or heat stress .try flushing it and move your light a bit away

How old are they?

There like a month old there about 1foot and 3inches tall.

*BUDS said:

How old are they?

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I think the ph is way out, when cheap nutes are used they have no ph buffers so the ph stays whatever the tap water is, good nutes like canna go to perfect 6.5 or very close to it every time in soil even with water at 8.8 (my water). You need a digital ph tester and adjusters about $40 all up. I dont think its salt burn as they are so young and you flush every 2nd feed, salt builds up in time after a lot of feeding. Also its too hot and they are not liking it, get it under 80 do your best.

I have a pH meter but its one of them cheap yellow ones that aways have to be recalibrated, So i just dont use it. But the cheap nutes i will be throwing out since I got the AN Base Nutrients now.

*BUDS said:

I think the ph is way out, when cheap nutes are used they have no ph buffers so the ph stays whatever the tap water is, good nutes like canna go to perfect 6.5 or very close to it every time in soil even with water at 8.8 (my water). You need a digital ph tester and adjusters about $40 all up. I dont think its salt burn as they are so young and you flush every 2nd feed, salt builds up in time after a lot of feeding. Also its too hot and they are not liking it, get it under 80 do your best.

Click to expand...