Intense light overworking/killing leaves.

I run a aircooled SE 1000w dimmable hps bulb in a 5x5x6.5 tent for flowering. my light is about 24 inches from the canopy(can't get it higher due to height limitation)

I run 9 plants in soil and net them up. My plants directly under the reflector always yellows up fast. It shows signs of N deficiency or cal/mag deficiency. I water every 48 hours. I've been feeding around 1200-1500ppm with calmag pretty often every other watering. And I also feed calmag in my normal waterings too in smaller doses.

I veg under t5 lights and barely need to feed them. They stay nice and green but as soon as move them in the flowering tent under the 1000w the problem occurs. I'm sure it's the 1000w light overworking the leaves directly under it.

Now my question is I could dim the light to 750w of I do 1000w one day then 750w the next and keep switching would that possibly help? I don't want to completely leave it on 750w because I feel like I would lose a good amount of yield, but if I leave it on 1000w the plant directly under it usually suffers and loses yield (bud won't swell too much due to loss of leaves). What would be my best bet to work through this problem without losing so much yield?

If there is anything I left out let me know! I'll post pics once my light turns on.

That's not too close for a 1kw HID. It could be with the increase in light intensity, the plant demands more nutrients. Are you burning them in? They need to be acclimated to the higher intensity light. A picture would help.

Yea would definitely need a pic. Sounds like your getting light bleaching and not nute burn but I would have to see to be sure. You can increase the light to 30 in and see if that helps. Your running at approx. 7200 lm/per sq ft. Increasing that light by 6 inches would drop you to approx. 5000 lm/sq ft still well within grow parameters.