Can fish have a bad reaction to salt? I've put in about 5 tbsp over the past 16 hours (a 20 gallon), and it seems to be affecting them strangely. Listless, floating, the 2 bigger ones are yawning a lot, and the little one is (still) gasping for air (see other posts for more info). Anyways, should I change some water (I just changed about 40% last night. Should I just get another airstone? Thanks.

The aquarium salt I just bought suggested 1 tpsp per ever 5 gallons of water. I think you may have put too much.

You should be able to go right up to a tablepoon per gallon without any ill effects. I have often used this method as a treatment with my fish with no problems at all.
What problem are you trying to overcome with the addition of salt?
Sometimes if you give fish really strong salt baths they can become listless and float because their gills can't handle the strength of the salt but this would indicate quite seriuos problems I would think.
If they are still doing this and you are really concerned then I would do a water change of about 30% and see how they look then.

the goldfish are that hardy with the salt, hunh? You learn new things everyday... I gues I'm just used to the concentration recommended for the koi, which seem to have a habit of being more delicate than goldfish.

The question is what kind of concentration did you want
If you want 0.1 (good against nitrite) you add 1 flat tsp per gallon
If you want it to 0.3 (used as medication against some parastie ) you add 3 flat tsp per gallons (or one tbs) I would do the latter in stages.

I think something else is going on in your tank. What are your water parameters
Ammonia
Nitrite
Nitrate
pH
?

shj

I'm using the salt to treat for fin rot and to help them get over ick. So, I was trying for the .3% concentration...I put in 5 tbsp for a 20 gallon, so I don't think that could possibly have been too much....would it make a difference that I'm using sea salt? My pH is 7.4, ammonia might be just a bit more then 0, and I don't have nitrite or nitrate testers.

You have something in your tank stressing your fish giving them ich and finrot and it may be a good idea to find out what that is. I would get the testers to make sure that it is not high nitrite or nitrate. What kind of water conditioners do you use? How long has your tank been running?

If you want to kill ich you should get the salt up to .3 in stages - but if there really is finrot you will need an antibiotic. How are the fins looking?

shj

The fins are looking good actually. I think that their on the mend...definitely not getting worse. The fish seem to be okay, except for the one gasping for air. I"ll see what I can do about getting the tests...what could I do in the meantime?

Waterchanges are good to prevent stress - weekly if you have no ammonia. If fish are gasping it may be lowered oxygen levels (or poisoning) and my first reaction would be the measure the water pH, ammonia, nitrite and nitrate and then do a waterchange of about 40%.

Is the fish still gasping?

shj

Yeah, it is still gasping. I'm gonna do a 40%water change now, and then head to the pet store...I'll buy a tester and another air stone. I figure I'll airate the heck outta my tank, and is he's still gasping, then I know at least that it's something serious. My water is actually looking a little cloudy now...whereas it used to be sparkling clear before....could that be affecting t hem? Thanks for the help.

First off I think thats too much salt. Especially dont do 3 tbsp per gallons–thats almost brine. I almost did the same thing when I was treating my fish and was told that concentration was much too high for any freshwater fish. It will only stress them more.

If the tank is cloudy then it could be a bacterial bloom. Is your tank new? Is it cycled yet? Sometimes things can disrupt the cycle–ie changing the filter cartridge. Your best bet is to do water changes for now and dont add anymore salt! For the record when you do add salt you want to add it very slowly over a day or two, not all at once. And dont do more than the 1 tbsp per 5 gallons. If theres a parasite problem treat it with Coppersafe or Quick Cure.

No-one suggested using 3 tablesppons of salt per gallon. I suggested 3 teaspoons which is equal to 1 tablespoon and makes a 0.3% solution. This is absolutely fine for goldfish and cures a multitude of sins. It is possible to go up to 3 tablespoons per gallon (a 0.9% solution) but only in extreme situations and cetainly only for quick salt baths and not any longer than a couple of minutes max.
A 0.3% solution however is perfectly safe for the fish to stay in for long periods (I sually keep it up for 2 weeks when using it as a treatment) and acts as a tonic, destressing the fish, opening up the gills and killing any nasties which might be lurking such as ich and some parasites.

I have yet only added about 6 tbsp to the whole tank (I've been adding it slowly, and due to all the water changes, haven't gotten it higher then that). So, I don't think it's possible that it's too much salt. My fish all seem to be fine, at least the two bigger ones, they don't show any signs of disease anymore...but the smallest is still gasping....I'll keep adding salt, and hopefully it will help him fight off anything he's got....any other suggestions?