PAUL wrote:
I normally use tap water straight to my tank and I haven't had nay issue yet.
and I don't use any additives or anti chlorine nor prime.. how big is your water
changes? if you do not want to use any chemicals, just do a 20% water change in
2 consecutive days straight from the rap and you will be fine... then monitor
your water until you are due for another water change.
Paul it depends on where you live...hear in the UK water is recycled many times and ends up being used time and time again this means water treatment plants use alot of chemicals to sterilise the water and possibly more chlorine also the water picks up heavy metals from the pipes the water travels through and the way it is stored during treatment..for this reason no matter the place you live I would never add tap water straight to my tank NEVER.
If the water comes from a wel or some other natural source like a spring that's fine....otherwise treat your tap water always!!
If you read the bottle of treatment it should have directions for use and will tell you how much to add to a standard 8 litre bucket or you can do some maths for whatever container your using

hope this helps