yellow leaves holes and dark brown stems

i am having some more problems but this time they are more serious. my leaves are yellowing and they are acquiring brown spots an dying it is very truly sad. here is what i got i have five plants in three gallon containers in fox farm ocean forest soil. the ph of the water is 6.5 and i use worm castings and fox farm veggie growth fertilizer. the plants get watered every day and a half. the light is a sunsystem 600w hps light with super sun reflecter relative humidity is kept at 50 percent and the temp at 73. The light is being cooled by a duct running outside my window with an 80cfm fan with air coming in at 35 degrees. also i am growing three indica thc bomb and two sativa thai stick. any help would seriously be absolutely AMAZING! i'll say thank you to anyone that helps ahead of time. have a great day everybody.

here are some photos:

you need to supplyus with a wide shot of the whole plant

that first pic-plant looks overwater. the other 3 looks like she is hungry for nutes-can see an N deficiency coupled with P deficiency judging by the light uniform yeloowing (n) and the twisted, dead brown necrotic growth tips (P).
I think day and half is too much watering from them and most of those soil nutes are gone by now. need to spread out your waterings abit and up your nutes. how old are they and when will they be flowering?

i thought nitrogen deficiency myself too they are about 5-6 weeks old and should be flowering in the next week or two. growth has definately slowed i can visually see that so it might be a bit longer. P is phosphate no? how can I give it more? I have worm castings for nitrogen already.

i think molasses