oi oi willy welcome to the burns ward....
yeah you can replace the old carbon in your filter, but only if you didnt get a cheap sealed can
like me haha the better quality ones you can take apart, difference in price isnt that much i might get a decent one this go round.
as for the mites well i think ive found the solution, some american bed bug killer hot shots pest strip or some shit its called i read a thread just today and the old timers said its all carcinogenic n blah blah this youll die that, but i reckon a shbort burst will do the fuckers in and not taint the weed. if it kills me i wont care is my figuring.
i use Canna coco A+B and canna pk 13/14 for a booster the a+b are cheap as chips £12 for a litre of both A and B but the dose is 4ml per litre so im racing through it. the NPK is quite low in comparison to my normal soil nutes but the babies dont seem to have any complaints, ill see what the yeilds are like soon enough...
thanks for stoppin by