HELP!! please

hey eveyone. im new here and to growing. i have some issues with my leafs. they have brown spots all over them. its like plaque in a way. the stem of the leaf is purple aswell. it only affects some leafs. mostly where the buds are growing. the new rowth on bottom is ok not free of the issue but not as severe.
i cant find any pics that look like my leafs or the spots on them. this has been going on for atleast 2 weeks.
i did have problems wit my ph in my res. it was well below 3ph. i did a complete water change and flush. i even washed off the roots with ph water. i added another nute solution about 1/3rd the strength. i have also had problems wit humidity. it has been around 20-35%H. i have added water bowls and wet towels i also have been spraying the walls and floor during light hrs. at night i have been spraying a cal mag with water spray once a night. but stopped a few days ago cause of the issues im having. i switched to just ph water. i also sprayed last night with a liquid light solution. the strongest nute in that is magn. its at .29% all others are .05%. i dont know what to do any help is well apreciated. thx for the help peeps.
also if you need different pics of the plants or my setuo, etc let me no i will do whatever it takes to get the best results!
i have more specs down the page on a reply msg with pics. i DESPERATLY need help!! please

What are you feeding and what type of water? A PH of 3 indicates that you needed a change and probably more nutrients, not less. A low PH is a general indicator of not enough nutrients. I'm also curious as to what your NPK ratio is. Can you also do a full size shot of plant, so we can see hydro method, and plants medium size, environment, lights, etc.

I suspect a deficiency in Phosphorus, because of the description of purple stems, veins and the splotches on the leaves. Phosphorus is also locked out at anything outside of 5.8 - 7.0 PH. Marijuana loves P and many strains can handle high amounts of it. I suggest you check your PH every 6 hours and adjust food accordingly. Your PH will begin to stabilize when you are near the perfect PPM in dilution. If the PH goes down, add more food. If it goes up between readings, just add water until it stabilizes and then get a good ppm reading and maintain it until the ph begins to swing again.

my ph when i first test it out of the faucet is right around 7 ph. i only have the cheap ph kit. after i put nutes in i test again then it goes well below 3ph which when mixed is deep red and according to chart thats 3ph or less. i use a ph up.and bring the nute solution up to around 6-7ph according to chart. the nutes in the pic are in order i mix them in. except for veg. also i noticed a difference between that last flush. before the mix was real dark brown and stayed around for a couple of days. this time at 1/3rd the water was clear after about half a day when i checked. does this mean anything ? i also use hygrozyme every feeding.
my lights arent the best. at top is a 150w MH bulb and on the side is a 2 foot t5 system wich i think is doin more for the plants than th MH.
i know MH is used for veg but at the time i didnt know either did the sales rep. lol go figure. but now we got a hydro shop finaly but i cant afford a hps yet. my lights are on 12/12 cycle and cabinet is just about air tight so definetly light tight. im using a 6 foot cabinet and only 4 feet of it is used for growing. its 1 ft deep and 21/2 wide. im also using 2 4in 184cfm booster fans 1 intake at the bottom (shown in pic #7 goin left to right)
the nutes im using is botanicare pro
pure blend pro grow 3-2-4
pure blend pro bloom 1.5-4-5
liquid karma .1-.1-.5
cal mag 2-0-0
hydroplex 0-10-6
floral nectar sweetner pineapple rush 0-0-1
usualy keep 5 gal. in res. with 2 air stones and a pump to circulate

Serapis said:

What are you feeding and what type of water? A PH of 3 indicates that you needed a change and probably more nutrients, not less. A low PH is a general indicator of not enough nutrients. I'm also curious as to what your NPK ratio is. Can you also do a full size shot of plant, so we can see hydro method, and plants medium size, environment, lights, etc.

I suspect a deficiency in Phosphorus, because of the description of purple stems, veins and the splotches on the leaves. Phosphorus is also locked out at anything outside of 5.8 - 7.0 PH. Marijuana loves P and many strains can handle high amounts of it. I suggest you check your PH every 6 hours and adjust food accordingly. Your PH will begin to stabilize when you are near the perfect PPM in dilution. If the PH goes down, add more food. If it goes up between readings, just add water until it stabilizes and then get a good ppm reading and maintain it until the ph begins to swing again.

Click to expand...

how do you adjust food accordingly. how will i know what to add ? is this just the basic nute n,p,k scale or others aswell? i dont have a ppm meter. is this an important item besides a ph kit ? or is it a ph tester? idk!? lol thanks for the help

Haven't read the whole topic but the pictures looks like mag def or P overdose to me. Might be caused by pH, might not.