Plants wilting after one week of 12/12. Need help.

I've been doing this a while with no problems. Years in fact. About 6 months ago disaster struck. I'm growing in 45 gallon tubs. I have a pump spraying water up in the roots, and air stones in all my tubs 2 plants per tub. I'm using Super Natural Brand nutrients. Grow for the veg cycle and Bloom and then Superboost and Bud blaster for the flowering cycle. I usually switch to the SB and BB after week 2. I'm using sunleaves rocks as a grow medium in 5 inch net pots. I run my water through and r/o system that has the filter that removes chloramines(sp) as they have caused problems for others in my area. I have 2 400 watt MH in veg and 2 1000 watt hps in flowering. My plants thrive in the cloning and veg stages. I usually give them 4 weeks and then add them to the bloom room. For the last 6 months this has been happening the plants will be fine and I will check on them and mist them with water throughout their night cycle then after about a week of 12/12 when the light kicks on they wilt. They pop up again with the light off, then wilt when it comes back on. The bottom leaves start to get yellow also the growth seems to slow. This goes on for a couple days, then if they stop wilting, most don't they just die, they start to grow again, but all the leaves from the bottom up yellow. I have my nutes in flowering at around 1000 I usually let the nutes sit for 24 hours so the ph can level out. I am at a dead end. My peeps in my network are also stumped. I'm hoping someone can help me solve my riddle. I have included pictures. Let me know if any other information can help.

Start with the ph. If thats fine, take a look at the roots and water level. What is the temp of the water compared to the air temp? You need a 10 degree difference between the two. Say your room is 80f your water should be 70f. Also you really should not spray them at night. The water just sits there and could cause problems. Hope this helps!

looks like it need some water. and has a nitrogen deficiency.

Check your sprayers when the lights come on to make sure they are working. seems they may not be coming on when the lights are on causing wilt. and then they get watered when the lights go out.... just going by what you have said and your pictures here. let me know if there is more information i should know.


Have you checked your pump to make sure everything is working correctly during light hours?

Ok to start with disregard the advice prior to this post. The issue is light intensity shock and is common when going from small MH to big HPS, you almost tripled the light intensity and your scratching your head as to why they are shocked.
All you can do is raise the HPS as high as possible for the first 2- 3 weeks and if you can have the plants not directly under the blazing 2000w for the first 2-3 weeks. Slowly bring them under the light.

I have the lights about 3 1/12 feet above the plants. I have had this setup for 10 plus years and never had the light problem. Do you think it maybe the bulbs? I change them yearly but last year bought some cheaper bulbs off of ebay. The plants start out only under one hps. Then room is 10x10 and the lights are on either end providing light for the whole enviorment. I see no leaf burn at all.

I was thinking nitrogen too. The water and pumps run 24/7.

light intensity shock good answer, good answer. I like that one, that is a new one on me. You are all some smart mother fuckers.

The leaves look like a N def, but that doesn't explain the droop. It could be a lock out due to excessive salts, but I am sure you have flushed them. As Buds mentioned, light intensity is a definite possibility as it only occurs with the lights on. I wish you luck.

Thanks it was in fact the PH. I guess the Super Natural brand isn't ph ng like it was, or they have stopped. The PH level was 4.0 after the bloom aqua was added. The difference is night and day. Also have my sprayers going 24/7 as my girls don't like them shut down at night. Sucks I lost 4 awesome strains. Oh well lesson learned ALWAYS check the PH.