You have ammonia in your tap water? I have lived in a lot of places and never seen an ammonia reading in tap water. Do you drink the tap water? I know that this may sound extreme, but IMO if the water from your sink isn't good enough to drink then it isn't good enough for your fish.
If your 10g tank is doing well and has been for a while, you can take some of the filter material (like a cartridge with some goop on it) and place it in the filter of your new tank. This will seed your new tank with the nitrogen-fixing bacteria that destroy ammonia. Simply put, a bacterium eats ammonia and outputs nitrite. Another eats nitrite and outputs nitrate, which is harmless except at extremely high levels. So, take some of the stuff (quite literally anything) from your old filter and put it in your new one and some bacterial colonies will migrate.
|