(06-09-2016, 08:51 PM)Novelangel Wrote: Did you allow your tank to fishless cycle for a week or so before you added the goldfish? All aquariums need to run for a while to build up a stock of beneficial bacteria before the fish are added. This enables the tank to keep itself adjusted better to the changes that naturally occur in the water as a result of fish being added. When the fish defecate, ammonia is released into the water, changing the PH balance dramatically. The bacteria eat the 'fish poop', which keeps the ammonia levels down. The fish help keep the bacteria alive by feeding it, and the bacteria help keep the fish alive by cleansing the water. The easiest way to cycle your tank is to simply avoid completely cleaning the aquarium. In other words, don't remove ALL of the water from your previous fish. Instead, leave an inch or two of water from that fish cycle. Then you attach and activate your filter and you have begun your fishless cycle. You might hear that you need to wait an entire month or more before adding fish, but truthfully, it doesn't really take that long as the bacteria builds up quickly. Don't add any chemicals to the water to keep it clean during the cycle time, as this will prevent the growth of the bacterial bloom that you need to see happen. If the water gets a little bit cloudy that means you have too much bacteria. If you see that you need to remove a third of your aquarium water and replace it with clean water. This is the easiest method I can think of for getting the proper balance to your aquarium, but you can also start with a completely clean tank and add a little ammonia to cause the bacteria to develop in your tank. Either way, the process shouldn't take very long.
Fishless cycling takes more than just a week or so. Unless you use a live bacteria product such as Tetra Safestart or some other form of heavy seeding to get it jump started, it will take more than a month to complete. You also need a source of ammonia just to get it started. There is no ammonia in an empty fish tank if you do not add it.
PH balance is also not the concern here when it comes to a uncycled aquarium. It is the ammonia and nitrite, since they are both toxic to the fish. Only in a fully cycled aquarium the PH might drop when there is too much nitrate converted from ammonia and nitrite.