first, thnkx all 4 ur replys
its really ment a lot 2 me, as i nvr thought that anybody would care

really really thnkx,
then,
my tank is a small one, the traditional small ( ball shapped ) tank
with 3 small fish in it...each one is about 1.5 cm long...
i feed them twice a day, and i change the water every 4 to 6 days..
wht is the ( air stone ) i donno it.
but i askd sm people thy told me that i dont need that air blower as it is a small tank..
and ill tell u more as soon as i know more about my lovely fish

sorry 4 my poor english language, but im trying 2 do my best,
as my mother tongue is Arabic as im from Cairo ( Egypt)