Pop-eye in itself is not a disease but is more a symptom of an underlying infection. The eye bulges out in this manner because of fluid build up, either behind the eye or in the eye itself. The first signs you will notice is that one or even both eyes are starting to bulge. Slowly with time it can bulge to such an extent that the fish will look really shocking with the bulge.

The bulging eye may have a thin layer of 'skin' around it, this is a tough tissue that covers the eye keeping it in the socket and as the eye bulges it stretches the 'skin' with it. The fish may also get less active and show no interest in food. Fungus infections can show up afterwards.

The effectiveness of any UV sterilizer is determined by the UV bulb wattage, the age of the UV bulb, how clean the quartz sleeve is and the flow rate of the unit.

In nature, ich is not much of a problem. There are large numbers of fish to which tomites can attach. And with the greater amount of water volume, it's likely that many ich organisms do not even find a host. However, in a closed system like an aquarium, ich re-infects the same fish over and over, resulting in severe infestations. That's why it can be such a problem.

While ich is encysted on the fish, no medicine can affect it. But once it's free-swimming, it can be killed. Since the life cycle of ich takes at least three days at 80 degrees to complete, ich must be treated for at least four days. I prefer to treat for a week.

The affected fish should be immediately taken out to be separately treated. It is difficult to specify a specific treatment unless the main cause is definitely known. Large daily water changes should help, if not Epsom salts has been used with good results to draw the fluid out. One tablespoon per 5 gallons of water for at least three days, longer if necessary. Epsom salts isn't really salt (sodium chloride) it is Magnesium Sulfate. If water quality is the problem, a 50 percent water change must be made as soon as possible.

Along with a temperature change and added aeration, I usually add about one teaspoon of canning and pickling salt per gallon to the water to help the fish recover from the stress caused by the disease by reducing osmotic pressure, enabling the fish's own immune system to fight back. Salt is also harmful to ich.

Water changes are extremely important in fighting ich outbreaks. Using a gravel washer, I do a 50 percent water change on a daily basis. This eliminates a great number of trophozoites and tomites from the aquarium.