Help needed ASAP for leaf issues during flowering

more info plz and pics of the girl would help how long you been flowering? soil? nutes? temps?

Very bottom leaves only? Or mixed around the plant, also are u running hydroponics or soil.

Did this start bottom-up? Did the leaves yellow all over, and THEN develop brown spots?

If it's "yes" to both questions, that's nitrogen deficiency - very common in early flower. That even yellowing in your pic's sure looks like it. N demand is very high during stretch; alot of people switch to low-N foods at 12/12 however due to marketing hype of various "Dutch" products and the like, and yellow fans and premature leaf drop is what results.

If your browned areas came on concurrently, or first, we'll need more info like some full-plant pic's, and what soil and nutes you're using. That could be a little more complicated.

when you go to flower and switch to flower nutes, this will happen, it's called yellowing off. you don't say how long into flower you are. but towards the end of the plants life, this is what happens and is totally normal.

The girls are in their 5th week of flowering. I am using a 1000 watt hps with 6 girls under it. The tallest plant including its pot is about 4.5ft. I grow in sunshine which I'm sure a lot of you are familiar with but just in case you're not, it's like soil but has a neutral ph and no nutes. I manually water the plants when they are light in weight initially using Earth Juice grow during the 18/6 veg stage i had them on and when I switched to 12/12 I switched nutes to Earth Juice Bloom and Earth Juice Catalyst. I primarily gave the plants all the weakest dose possible occasionally bumping up the veg towards the end of the 18/6 light regimen giving then standard strength 1 tbs per gallon of h2o rather than 1/2 tbs which I gave in the beginning. I started with the weakest bloom and catalyst dose as well at 1/2 tbs but after about 2 and 1/2 weeks of flower jumped to the regular dose of 1 tbs per gallon of water. I can typically water 2-3 plants with 1 gallon of water and the pots get heavy but no drainage from the holes. I flushed the plants per advice given to me with 2 gallons of h2o per plant for a total of 12 gallons. This at first seemed to help the issue and since I gave each plant 2 gallons I have not watered them in several days. Today however i noticed the problem has spread to new ares of the plants before, it primarily effected fan leaves but know the brown spots and yellowing can be seen even on the leaves that come out of the buds. The temp. is generally about 80 degrees with the lights on and in the low 70s with no light. It has fluctuated all the way to the high sixties up to the low 90's. I'm in a place where unless it's summer, the weather can be freezing or lovely during the day this time of year. The water I use is from the tap and i have no clue as to its ph. The light is over 2 feet away from all the tops of the tallest colas except for one gargantuan plan that's about 19 inches from the hps hood. I have ruled out the light itself because even lower leaves have the issue. I guess heat may cause similar issues. I think that this is either a lack of nitrogen a potassium deficiency or both. I'm clearly not sure though. Even during the veg stage, I noticed quite a decent number of fan leaves turn yellow on my girls. I have grown before and other than the really rare leaf, I've never lost many. I can tell this will effect my yield but I hope to reverse it soon as there at least 3 more weeks of flowering left. I will post some more pics of the girls themselves as soon as i get home. I hope this helps and am looking forward to your ideas on what this could be.

Oh yeah, it didn't start from the bottom up but it never effected the very tops until today always just the rest of the plant.

You didnt mention...do you know the relative humidity of the room?

Im a fellow Earth Juicer and if I were you I would give them a normal..maybe mild dose of veg..sounds like nitrogen deficiency and is very likely as EJ bloom has none at all..I always supplement with veg two weeks into flower so I don't get premature nitrogen deficiency.