Did you say this was a tank you are cycling?
These products definately work. I've used them straight for a whole year on two overcrowded uncycled tank and on a 3rd seahorse fry raising tank which is perhaps the most
ammonia producing tank you can have set up
IMO. When I saw the fry getting antsy I would throw in some
ammonia binder and they would settle very quickly. I've used them intermittently for years before they were even in liquid form.
As far as
ammonia you have to make sure you are testing with a Salicylate-type reagent test kit and not Nessler. The Nessler will always say result positive but the salicylate will be negative appropriately. As new unbound
ammonia is produced it will be detected by the salicylate.
As far as dosing with Amquel and not testing until the next day.... the product is only good for 24 hours. By the "next day" the
nitrite would have become unbound and is indeed back in your tank in it's harmful form. Put the Amquel in cup with some tank water, give it a good shake and then put it in the water a give it just a little time to mix. Say 20 minutes alter test and see what you get. I've never known a test to become positive for
nitrites after I added the solution.
I've always used the product Ultimate. Prime and Amquel+ stink like skunk after a month of being opened. You are also not suppose to mix different product in the same tank. They may have the same effect but they are not made up of the same compounds and don't play well together.