Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
A few more ideas:
1) Goldfish handle salt (NaCl, like table salt) really well. Add 1 teaspoon of salt per 20 gallons to reduce the amount of nitrite that crosses the gills.
2) Fish that cannot keep their balance may be suffering from a problem that happens when the new water has less minerals than the old water. You can add salt (NaCl, up to 1 tablespoon per 5 gallons) or Epsom salt (1 teaspoon per 5 gallons) or a combination to help. Do not use reverse osmosis or distilled water. Add either or both of these slowly. Dissolve them in water and pour the water into the tank a little at a time over several hours.
3) Do not use medicines that kill bacteria when you want the new bacteria to grow. I suspect that the symptoms you are seeing are due to ammonia, it burns tender tissue such as in the fins, not disease organisms. Keep up the water changes, and give the Tetra Safe Start a chance to get growing before trying medicines. The problems might clear up by themselves once the water issue is taken care of.
4) Feed lightly. Goldfish like vegetables, and there is less nitrogen (protein) in plant based foods. Perhaps half a pea per fish every other day, or every third day, and a 1" x 1" leaf of lettuce left in there for a few hours on the other day(s). Remove any food (like vegetables) that are not eaten in a few hours.
5) Tetra Safe Start has the right bacteria. Nitrospiros. I have seen some good reports of the Fritz product, but not the ingredients. I have not seen good reports of most of the other cycle-in-a-bottle products. I have seen the ingredient lists. Of course they do not remove ammonia or nitrite. Wrong species of bacteria. The right ones were identified roughly 10 years ago. Look for Nitrospiros in the ingredients. Dr. Tim's One and Only is another product with the right bacteria. Microbe Lift's Nite Out II is another. Give any of these a chance to get attached to the filter media. Do a big water change before adding them to get the ammonia as low as possible, then do not do water changes for a few days.
6) A larger container is a good idea, or separating the fish into several containers. Even running the small filter on a larger container (plastic storage bins are available that hold 15 gallons on up to at least 60 gallons) would be better than a 10 gallon tank. More water will dilute the waste better. Be careful with the larger storage bins, though. They are not meant to hold water, and will sag. Perhaps to the point that the water overflows. Prop them up with bricks or other sturdy things. A child's wading pool would be great, if you have room for it!
Hang in there, things will improve!