You have to de-chlorinate most municipal tap water...
I have always had stock in my tanks when using "STABILITY"
Follow the directions on the bottle, it says to de-chlorinate the water first with Prime or equivalent... and the STABILITY you have added already doesn't count since there is still chlorine in the water...
If you use Prime or Amaquel to de-clorinate, your water will have a slight sulphur smell to it, at first.
one more thing...Shake, shake, shake, then shake some more, on the bottle of de-chlorinator and "STABILITY" it should be milky white...
good luck with your new tank, most folks new to the hobby start smaller, good to see you "jumped" right in...