hey there mate can you post a picture...

how old are the plants and at what stage are they in... 3rd week veg. 6th week flower etc.

your tap water ph source is stated but whats the ph after youve added your nute and additives but just before you give it to the plants??? it should be between 5.2-6.2 if your hydroponic and 5.8-6.8ph if your in soil. certain nutes will get locked out at ph values higher or lower than those stated.

its normal for a plant in the very later part of flowering to loose leaves.

what is the ppm-ec of your nute solution by the way...

sounds like to little rather than too much...
foggyman Reviewed by foggyman on . Yellow discoloration and dying branches The leaves of my girl in bloom are getting yellow on them and dying mostly on the lower branches the top and middle of the plant look great E- Indoor E-Soil E-specific medium Not sure what this means.... CSL-Soil type/brand Black Gold .13-.5-.10 HCL-Hydro/aero/soilless system type SCL-Miracle Grow during vegatative stage and Tiger Bloom during Flowering SCLR-Soil or slab runoff pH (Unknown) Rating: 5