I could be wrong, but did you say you do a 10% water change every TWO WEEKS??? If so, this is way too infrequent.
Waiting this long to do a water change will allow toxic substances to build up, and just means more risk for your fishies. Not to say that is what caused your fungus, but toxins always exist in the aquarium, its when fish become stressed that these toxins become a big threat.
You should be changing a MIN of 10% PER WEEK. I usually do 10-20% changes twice per week, you will find most avid keepers to frequent changes for the health of the aquarium. If you are going to insist on every two weeks, make it a 30% change, never more than 50%.
Waiting this long to do a water change will allow toxic substances to build up, and just means more risk for your fishies. Not to say that is what caused your fungus, but toxins always exist in the aquarium, its when fish become stressed that these toxins become a big threat.
You should be changing a MIN of 10% PER WEEK. I usually do 10-20% changes twice per week, you will find most avid keepers to frequent changes for the health of the aquarium. If you are going to insist on every two weeks, make it a 30% change, never more than 50%.