Is this supose to be happening?

Hi everyone, I posted on this site before, trying to start my pretend hobby,1st time all males, This time 3 fem's, they are honey b,sweet tooth,and red diesel, 1st 2 are in 3gal pots red diesel in 5gal.using soil they are on 12/12 cycle, nutes im using now are Tiger bloom and big bloom. I am in the 6-7 week of flowering and all three plant leaves are starting to have problems.My sweettooth, is pale or light green with some yellowing leaves with brown spots,my honey bee leaves are yellow on the edge of the leaves and red diesel is still dark green but is clawing under,.I flushed all 3 plants last week and again yesterday, still the same.My temps are 70-80 day and 65 at night.they are under 400w hps bulb. I water every 3-4 days. here are the pics,,,,,,thanks for any help that you can give me.

the yellowing leaves with brownish spots/stains is a pottassium deffiency m8 the clawin leaves could be humidity problem

here are pics of my girls just a week before, ,,,,

GUD2TOKE, HI, how do I get pottasium to the plants? I mean what should I buy and how do I apply?

add a layer of potash on top of medium m8

sulphate of potash.... not weed ash hah.... coudlnt resist that one

Perfectly normal for the leaves to start yellowing and even dropping off,it the end of autum comeing into winter in the plants mind...................easyest way to put it.......................tyke...........................

http://www.gardenhealth.com/products/plant_food/sulphate_of_potash_fruit__and__flower_food.html/ you owe me a spliff lol peace out

hey man, is this a sativa dominant? strange you dont have orange hairs on any of them if it isnt... anyways, yellowing and dying of the fan leaves (strating with the lower one usually) is pretty common from the 3rd-4th week of flowering... i wouldnt go out of my way to get more nutes at this point if thats the case... if its the top leaves having the trouble and the bottom ones arent then i think you should get some more opinions

YOU HAVE GREAT BIG BUDS THAT ARE ALMOST DONE!
DON"T GO PLAYING GOD AND TRY TO SAVE A PLANT THAT IS DYING, AS IT IS SUPPOSED TO DO.

If you want to add something add some micro nutes like Cal/Mag+.

Your plants look great, just keep doing what you are doing.

Bonzi where can I get cal/mag from? can I get it at home depot or Lowes? and how would I applyit?Thanks so much for the reply also appreciate all comments .

Any hydroponics store, or Amazon http://www.amazon.com/gp/product/B000J2CUPW/ref=olp_product_details?ie=UTF8&me=&seller=

trust me m8. just add it to one then and see which gives u bigger buds. maybe to late but dont worry about adding it to top soil. wont bother the flushing one bit. without sounding too technical. we only flush the nitrate salts from plants. nitrate salts are in the nitrogen "N: from the NPK ratio in nutes... read the npk of the potash???/ its 0.0.48 so doesnt matter the flushing process...... as for trying to save a plant that dies anyway ???? the leaf being that colour is telling you that it has a pottasium deffiency??? so i would add it