established tank added new fish two dyed and one has ick

Question
HI, I am so overwelmed with all the differing opinions on what to do in my situation that I figured i would go online to find answers myself.  Wow lots of opinion there too.  Well, I have a ten gallon tank that has been going for 6 months now and origionally we had two goldfish.  One got trapped in the filtration system and dyed so we decided to get some fish finally for our tank.  We got two dalmation mollies two albino corydoras and three mollies(black, yellow and red.  About a week later the origional goldfish died and so I went back to get my water checked at the pet store and all levels were fine ph, nitrates etc.  I did a 10% water change at that point and waited to see what would happen..A week later now one corydora has died and I noticed the black molly has white spots, Ick.  So I went back to the pet store got some cycle and quick cure, water checked out fine again so I started treatment today for the Ick.  I took out the carbon filter(Elite10 gal) and added ten drops ( 1per gallon).  Now online it is telling me to treat the tank for 10 to 14 days where as the directions on the bottle say 3 days as does the pet store.  What do I do?  Some say add table salt (is that ok for corydoras?) I always have done water changes every month 25%.  Some say every week 10% in between ?  All this differing advice its confusing.  Can you guide me during this ordeal because my kids and myself just want to enjoy this tank and the fish nad learn from it but so far it has been pretty stressful.  Thanks Maria.

Answer
Hello,

I am very sorry to hear that you are having such a rough go at this! However, I think I can help you in at least some areas.

We will first start with the ick medicine. If the bottle and pet store both say use it for three days, then you should absolutely follow their advice. Remember, anyone can put up a website whether they know about fish or not. What you should do though, is if the ich is not gone in 3 days, treat the tank with one more round of medicine.

Second, you should never add table salt to your aquarium. It will likely kill your fish. If you want to add salt to your aquarium, pet stores sell special aquarium salt. You are right though, it is best to avoid it with catfish. They don't thrive as much when it is around.

The best thing to do with water changes is 10% every week. That way, it is a small amount and not too much of the established water is removed. This is especially important for smaller tanks.

The fish dying seems to me to be caused by overpopulation of the tank too quickly. Every time you add a new fish, the amount of waste in your aquarium doubles, and it takes some time for it to become stable again. In a small tank like this, its best to add only as many fish as you have to. For examlpe, add one type of fish, allow the tank to adjust, then add another type, allow it to adjust, then add the final type.

At this point, the best thing you can do is continue weekly maintanance. Add Cycle, syphon your gravel and change 10% of your water every week. I believe though, that your corydora may have died from ich because catfish are quite sensitive to it.

I hope I covered everything, and that it can help you. If you need help with anything else, let me know.

Good-luck,
From Stephanie