Hi! This is my first time posting so bear with me.
I set up a salt water tank back in august and have had no issues until the last month or so. Just over a month ago, I had a major ammonia spike that led
to the death of my butterfly fish. I know that some of you will ask if the tank had cycled. I allowed it several weeks with roughly 80 lbs of live sand and I watched the ammonia cycle and allowed it to stay level at no reading for a couple of weeks before adding my fish. The fish had managed to stay happy and healthy until i saw the butterfly gasping for breath at the bottom. I checked the ammonia levels and they were through the roof. I immediately changed the water to get it under control but the fish was gone.
The ammonia since then has been under control until about 2 weeks ago. It has been reading high on my test strips and I have since performed partial water changes several times with no change in ammonia level. My fish however seem to be doing fine with the toxic levels present in the aquarium. My first question is why would the ammonia stay this high for a prolonged amount of time and why is it for the most part not affecting my fish?
Next issue was I was in the process of re-arranging stuff in the aquarium and after lowering the sprayer bar from the filter underneath the water I noticed my angelfish on the tank floor gasping for air. After I moved the bar back above the water, the fish managed to come back to the living. It was only ten or fifteen minutes after moving the bar that the fish was affected and took over an hour to come back. I think it was oxygen deprivation, but there is enough air in the water that I can see the small bubbles in the water. Bubbles form on most of the surfaces under the water and the water is constantly cloudy from what I thought was over oxygenation. I want to be able to lower the amount of air in the water so It wont be quite so foggy but my fish seemed to want to die with that slight change. Can a fish get used to high levels of oxygen and when the level changes not be able to cope?