ph problems ? white rhino

:( h33y guys .. can some one point me in the right way!! please:thumbsup:
im growing white rhino in soil
lights on temp is 28
lights off is 19
plenty of fresh air and circulation

be 4 i adjust my cf the water is 7.00
i take it down to 6.3 when fert is added
i tested the run off and its comeing out @ 6.3 when i flushed it with the plain water of 7.00

the plants are growing fast n strong ..the problem im haven is that they seem to have pale new growth ..limey green..this turns darker green as the days go by ..but are stll to my eye not as dark as they should be ..im in the 2nd week of flowering ...allso when i use plain water inbetween ferting ..what should i have the water ph @ ?--- i have noticed that in the weeks b4 that the new growth on the smaller new leaves sprouting that they are allmost yello ..mainly in the center ..then they darken to limey green ..after a couple of days they do go darker but not real dark as ya would like to see ?

so do i need to drop my cf even lower to get lush dark growth ? please help :D

I think your ph is too low, if going in 7.0 and coming out 6.3... that would mean that the ph of your soil is probably less than 6.0. More info here: http://boards.cannabis.com/plant-pro...hy-how-do.html

Also, when is the last time you changed pots? How old are the plants in total age? What size pots are they in now?

plants are 4 weeks from rooted cuts

2 weeks veg
2nd week of flower
the pots i can fill 3 out of a 40 litre bag of soil so they are of a decent size

so if the case is to low a ph ? how do i go about fixing this ?

many thanxs ..:DBoom

Dolomite lime is used to raise the ph of soil. Soil is normally made from peat, which is very acidic (ph less than 5.0), so they add lime to bring the ph back into the 6's. Either your soil didn't have enough lime to start with, or it is now running out.

Cold night time temperatures can also cause the newest growth to be yellow. Is it possible that the temps are getting below 19?

Some pictures would help if possible. There is a copy-and-paste troubleshooting form at the top of this section. Filling it out here makes it much easier to figure out the problem. Can't really give any advice without all the necessary info, like watering schedules and what nutrients you are using, and how often, etc.