New fish, healthy fish?

[al404]

6 weeks ago all my 3 fishes died in less then a week

saturai i add my first fish at my nano tank, it is a blenny
i would like to add 1 or 2 other fish, not 100% sure witch one but I'm scare that one of them is ill even if i can't see it

how long would it take before first symptoms will appear?
after how many weeks i can consider them safe?

[Marchillo]

Can you provide more information on your tank? What size is it? The blenny may grow to be too big for the tank. How much live rock do you have and what are your parameters - ammonia, nitrite, nitrates, SG, temp - those to start with. It doesn't sound like you are using a Quarantine. Meaning whatever killed your first set of fish could cause havoc with your blenny. IE if you had ICH it could stick around for 72 days. I am guessing your original 3 died either because you weren't cycled in the first place or you added too many fish too quickly and you caused a mini cycle. I wouldn't add anything right now and I would test your water every day, maybe twice. I'd also buy some Seachem Prime to have on hand and also some extra mixed saltwater in case you need to do an emergency water change. But since you did not QT I would wait a while to add any other fish.

[al404]

I started my tank in September and wait about a mount or more for fish, it was Brooklynella
http://www.reefcentral.com/forums/showthread.php?t=2546086

i did not quarantene this fish, i don't have a quarantene tank