Help me please !

Looks over watered. Are the leaves thick? means holding to much water

So they had run off water already , so I'm going with shock of changed spectrum and too much water. I've lowered the lights to 400W and I've taken away the run off water. Will update in next few days thanks guys

Maybe just heat from the hps cause them to dry out very quick if this is soil and is dry i would water heavily til run off and see if that helps

Your plants are in shock.. You changed their spectrum they're used to. And just cause your area is the same temp doesn't mean your leafs are that temperature. "LVPD", They should bounce back after a few days. Maybe, have a look at other ppl running similar lights.

So watering should be based on what the plant wants. Basically wait until soil is dry, then hit with water. I lift my pots and if they are light it's time to water or feed. During veg I will often let it dry out to the point it starts drooping from under water, I've heard it helps promote root growth, forcing them to extend to try to find water. Most people will say stagger feedings and watering. Feed, let it dry, water, let it dry, feed, let it dry, water, let it.. you get the point. Usually I will water and feed lightly until I feel like plants root system is developed enough to support water to runoff. Then I will water to runoff on the feed, and just water till I think its good on the water, water to runoff on next feed, etc.. If possible I would reduce the output of your HPS until the plant recovers, it could just be taking a pounding from the wider spectrum and increased intensity.

Yes so I was running led and a heater ... LEDs were bright ish . I've switched to HP's and got rid of the heater, it's pretty much stayed the same hear wise running at around 23-24 and humidity was around the same . Its definitely around 150% brighter with the hps, feels like a real light rather than some fake LEDs. I have looked at over watering. How much should I be watering ? I've been giving them water around every 2 days but spraying them around 2/3 times a day. Water has canna a and b in and has had some rhiz in to help them take off. All has been ok until 2 days. All/any advice is greatly appreciated

You went from LED to HPS? I'm guessing since I have never done that but is it possible the plants need to be hardened off like from going indoor to out? Looks like you are running HPS based on colour. I think HID bulbs tend to have way more UV/IR spectrum, maybe that could be having an effect. Also when you went from led to the bulb, does it seem a lot brighter or dimmer now? Another possible thing is bulbs tend to create more heat, did temperature change in area? Could also be over watered, but now I'm just throwing darts in the dark, I'm guessing if it started after bulb change it is likely environmental instead of something you are doing to the plants. Hopefully something I said causes something to click for ya. Other wise drop a little more info and we'll see where we can get ya.