New Fish dying after 3 days

[seanb]

I am having a strange problem with my tank, I have a 100g uniaquarium running fluval 300 and built in wet trim, also have skimmer on tank
Current Fish
Maroon Clown
Niger Trigger
Foxface
Flame Hawk
Yellow Tang
Humu Trigger
Blue Tang
Everytime I add a new fish they eat for the first day and a half and then dye no visible signs except sometimes I see white spots but no other existing fish in tank get affected
Ammonia 0
Nitrite 0
Salinity 1.020
Nitrate 10 or less
Ph 8.2
Temp 80-82
I just added a blue jaw trigger, and harleqium tusk they both died in 3 days, what could be causing this problem if the existing fish are fine, I don't know what to do please help anyone, I don't know if I should take all my fish or what and start over
Thanks
Sean

 

[beth]

Sounds to me like ich. You need to QT fish before they go into your display so that you can adequate treat them at the first sign of illness.
What type of tank do you have? If it is a strictly FO tank, you can treat the whole tank now using hyposalinity. Otherwise, I would set up a QT and treat all your fish in it.
Take a look at the FAQ Thread on the topics of QT and hyposalinity.

 

[seanb]

Thanks for the info Beth, but none of my existing fish are affected only every time I introduce a new fish do I have a problem, I am just puzzled as to why they die within 3 days they eat fine for a 1 day or so but then die on the third, sometimes it looks like they are gasping for air at the top of the tank

 

[beth]

Your fish that are "not effected" are...beleive me. They may be healthy fish that are just able to hold off a full blown infection but they are carriers. They are helping to feed ich and proliferate the parasite in your tank. New fish that are incoming are highly stressed, thus more susceptible to an all out infection [plus they most likely intoduce their own ich too since you're not QTing and treating].
Fish commonly carry ich.....very commonly. Thus, it is up to us to make sure that the parasite does not enter our tanks. Once introduced, however, and unfortunately, all fish and even the tank must be treated. They need to be treated with hyposalinity or copper, and the tank needs to be treated by leaving it wo fish for 3 wks.

 

[seanb]

If I treat the whole tank with hyposalinity or copper what salinity do I drop the tank to 1.009, if I don't use hyposalinity and I use copper, will it affect the tank and will it affect my live rock and live sand, let me know which direction I should take.
Also what is an optimal salinity level to keep in a tank once everything is stable

 

[beth]

You can not treat your display tank with copper. It would devaste it. You can use hyposalinity ONLY IF your display is FO. This means no inverts, no live rock, no corals, crabs, snails, just fish.
Is that the case with you? You will need a refractometer or a high quality glass hydromter.

 

[seanb]

Beth, yes all I have in my main tank is fish 100g tank, no corals or live rock, what does my salinity need to be dropped to I do have a refractometer, also how fast can I do the drop, and then how fast can I raise the salinity
Sean

 

[beth]

Sean, there is a post in the FAQ Thread that details the specifics. Basically 1.009 sg is the target. Calibrate your refract. You can lower over a 48 hr period, but you need to take more time raising the salinity [about 5 days].