hi got myself a juwel 125 complete tank yesterday (secondhand) with a few tetras included few questions how long do i leave the twin lights on for a day? feeding twice a day only a small amount what the fish eat in 3 mins is this ok ?tempurture of 25c done second water readings they are as follows ph 7.6,kh 6+d, gh >16, no2 0 no3 5 are these ok ? hav'nt got a test kit for ammonia is it worth getting one ? sorry for all the ? but only just starting out