Jonny_Maelstrom: Your are right on track!
You won't find pure ammonia easily -it's marketed for lab use only. A
solution of ammonia is what is readily available, just make sure it has no surfactants in it. Just grab the bottle and shake it, if bubbles dissappear quickly, that's the one you want; if not, leave it behind.
Your readings are normal. If you are using Tetra Laboret
test kit, that reading of 1.6 should be divided by 3.3, which means you have 0.48ppm. The 3ppm of Ammonia is probably half of what you would measure after adding some food fish. It just means that Ammonia spike (it was steady at 5 or 6ppm before, right?), is fading out, and nitrites are present!, congratulations, you are entering stage 2 of fishless cycling!, in a day or two, your Ammonia readings will go down to 0 in 12 hours tops, and nitrites will spike (way over 1.0ppm, that will read 3.3 in the color chart, if you are using Tetra Laboret test kit).
Try not to overfeed the tank, you need to feed enough but too much could slow down your cycle, I would go feeding half the amount of fishfood added for now on.
Good luck with fishless-cycling! I cycled with ammonia everytime, it takes 11 to 13 days to do.
Pepe
Santo Domingo
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