Hi again. I'm not telling anyone to add aquarium salt based on my word. You can find numerous articles on the web just by going to Google search & searching on something like "salt and corydoras'. The majority of the sites you'll find will say that people have had no problems with their corys and 1 tbsp salt/5-10 gallons water. I forgot to mention that over a week ago I added 1 tbsp/5 gallons to one of my tanks - neons, zebras, white clouds, and a cory. And I added that does of salt to my home tank a few days ago - platys, mollies, danios, neons, and a cory. In neither case has the cory, or any of the fish, shown any signs of stress. And my friend that has been using it for a much longer time has had no problems with his cory cats. Just a couple of quotes from some of the web sites:
".....I've had 2 cory cats for almost 3 years with 1-2 tbs./10 gal salt. They don't seem to be affected at all. Also my
pH is around 7.4. I have them with cichlids and everybody is happy."
"The problem with corys and salt isn't the salt itself but the fluctating amounts of it. Just make sure you use the same amount all the time."
"Some people have had problems adding salt to their cory tanks. The only difference I've seen is that I added salt very gradually, and they did not. Some species of cories are more sensative than others, but unless your
LFS specializes in catfish, you probably won't get your hands on the more sensative cories."
"some cories are actually pretty darn sensative. Bronze and peppered cories can withstand just about anything, but some of their relatives aren't so lucky..."
"A few, notably Corydoras catfish, are said to have very low tolerance for salt, although our experience has been that they do quite well at the salt levels we use. "
"In my aquariums both Corydoras and many plants will tolerate 1 Tablespoon of Aquarium Salt per each 5 gallons of aquarium water, and they do poorly with 2 Tablespoons of Aquarium Salt per 5 gallons. "
To me, the benefits of adding a little salt to the aquarium are worth it, and it may be just some of the less widely available corys that are affected. I know from my experience and that of a friend that the common cories don't seem to be affected at all by 1 tbsp/5 gallons water. I suppose some of the problems with salt & cories may be related to Ph, species, adding the salt too quickly or undissolved first, or other factors, but I haven't yet found a site with an article saying that their cories died when they added salt.
Add it at your own risk. I did and I've had no problems. Anything I can do to cut down on the risk of diseases, and to improve the health of my fish is worth a try.
One thing to be aware of - if you add salt to an aquarium with zeolyte in the filter (to absorb
ammonia) - take the zeolyte out before adding the salt! Salt is used to recharge zeolyte, and adding salt to zeolyte that has been in use can release all of that ammonia, which could be disastrous to your fish! If using zeolyte replace it with fresh zeolyte after the salt addition - it will still absorb ammonia at the low salt levels used in fresh water aquaria, but not quite as efficiently.
Terry