setting up new tank rock work questions

[K R Brown]

so far i've got gravel from quarry blacky grey

and heap of big river rocks , and blue lights looks quite effective will post pics up SOON

couple of questions thou :

had tank running for 3 years with africans and now it empty the filter should be all good to add heap fish or do i have to reintrduce them slowly ?

and the river rocks have a lot quartz in them will this affect ph water in any harmful way ?

cheers and thanks i know silly questions and google is not very helpful to many conflicting answers .

[spoon]

quartz is inert wont effect the the water if your filter hasnt been running for ages you will need to cycle the tank again rinse trhe filter mediua out before using it