The quality of tap water can really vary place to place, and even within the same area be really inconsistent. One day it might be great, the next week it might be chocked full of nitrates and phosphates. Many people choose to invest in a RO
filter of their own to produce pure water. Others buy RO
water from their local fish store, and others buy it from the grocery story. And of course, there are others that use tap water just like and have no issues.
But it sounds like you have an ammonia issue. Did you start using the ammo lock because you found ammonia in the water? Or did you just use it because that's what someone said to do? Also... I wouldn't overdose on the chlorine neutralizer. Pretty sure the directions are conservative to start with, and it's just that many more chemicals you're putting in your tank that probably don't need to be there. Maybe some of the chemists out there in the forum that know how those neutralizers work can tell us if overdosing on that could give you a false reading for ammonia.
And now that I've reread this thread... I'll ask the question again others have asked - did you cycle the tank? Did you see an ammonia spike, followed by a nitrite spike, and eventually those two things drop to zero and be replaced by a slowly increasing level of nitrates? That's what you should see during a cycle. If you didn't cycle your tank, then well... you are now. And ammonia is the first think you'll see.