I'll let the pics do the talking

Soil grow, light is 1000hps, about 18 inches from tops of plants, temp in room is around 76 when the light is on watered yesterday with molasses and 12 55 6 bloom booster. my question is why have my plants thinned out so much up top and yellowed. My plants had this look before i watered yesterday i guess it started about a week ago. the girls are at day 40.

It looks like the light is burning the top. I think 18" is a little close especially after looking at the pics. But, below the top couple of inches, the plant looks great. I would probably put the light at 22" and let it go at that, even if the top doesnt straighten out.

could be the case however I have never had a problem before with the light that close to my plants its not getting hot i have a cool tube reflecter that is hooked up to a 430cfm fan.

yah it definetly looks like its getting too hot near the top, get a fan blowing just under the light and on the tops of all the plants!

Not to doubt either of you, but i dont understand how this could be the case the temp at the top of the plants is no hotter than 80 ever this time of year its never about 75 or 76. I have two fans in the room that circulate the air great. Are there any other explanations that could be the reason for this.

what kinda nutes and other shit as well as pH of soil and water? as well as ppm of nutes? overnuting or under nuting

ph of the soil for all the plants is around 5 not sure of the ppm however the nutes are used at about 3/4 strength. I am not using anything great for nutes its simply green light super bloom flower food 12-55-6. I have only used nutes twice on the plants since they have gone into flower. once at day 24 then on day 37. the pots are in stacked two gallon pots with the bottom cut out of the top pot this allows me more soil and i dont have to give up any space. i just started using molasses on day 37 as well. any help would be great if nothing more than to not make the same mystake again on the next cycle. included are two picks of my set up. the left are my clones at the bottom and mothers and seedlings at the top. the right is my flower chamber.

I dont think it is the heat from the light. It is more of a light poisoning. My plants went through the same sort of thing in flower. I am guessing they are more tender at this stage. It is just a suggestion though. It looks like no deficiency that I am aware of.

The top leafs look deformed and I've known that to be caused by a micro nute deff. Can't remember what one thought I'll look around and I'll post again if I find it. Only thing wrong with it being a micro nute deff is that's a soil grow and thats extremely rare unless you are reusing dirt or the PH is off, but you said it was about 5 still I'd lean towards that. As with the temps you reported there is no way you are burning her. Well good luck but seriously recheck your PH

i see that happen when they get to close to the light. it's not heat but intensity that i think causes this. my buddy does 40 plants on a flood table and all his plants closest to the lights always do this.

I have moved the light up to 22 inches from the top of the tallest girl. I guess all I can do is wait and see what happens kinda discouraging.