Need help with saltwater fish

[Hobbes67]

I am wondering what Is going on with my tank? I'm on my third month, since I set up a 40 gallon tank. I added 3 sm. hermits and they are doing great, they are all over the tank like crazy now for about 2 months now, but it seems that every time I try adding damsels they do good for about a week or two then die, this last Friday I bought one domino and a four stripe and they only lasted till Monday morning, I did a water sample at a lfs, and I have no ammonia, and he just said I have very little nitrite and hardly any nitrate, that I should be fine to add fish in a week. Now why is it that the hermits are doing great and the fish are not, my salt is at 1.021 any suggestions, will help thanks.

 

[all4wheels2]

Did your tank cycle properly in the beginning? If not, then there is no beneficial bacteria to handle the bioload of the fish, and so they will die. As soon as there is no bioload (the fish die off), the levels drop back down to zero. If you have some readings of nitrites and nitrates, then the ammonia level spiked at one time prior. They work in sequence, usually: ammonia --> nitrite --> nitrate. Some people always have nitrates, but ideally they should be less than 10ppm. Nitrites should always be 0ppm.

Hermits don't really create a bioload, so they will not cause a tank to cycle.

 

[Hobbes67]

I cycled the tank for a month before I added a couple of damsels.

 

[Coralreefer1]

How did you acclimate the Damsels and for how long? It is possible that you purchased unhealthy fish from the pet shop also!

 

[weagle117]

I can't make chromis or the blue ones on top/yellow on bottom damsels live in any of my tanks. I do ok with the blues with the yellow tail... My tank is 10 yrs running & I drip acclimate my fish..... go figure.....

 

[Hobbes67]

How did you acclimate the Damsels and for how long? It is possible that you purchased unhealthy fish from the pet shop also!

I left damsels in bag for about 15 min. And added half cup of my water every 15 min. For about 3 times then pull each fish with net out of bag into the tank.

 

[Sniperhank]

That isn't even long enough for them to get used to the temp change. I keep my fish in the bag for a half hour. I cut a hole in the bag so they can get fresh air. I'd recommend using a QT though. If you don't you can run into issues like ich. I had that problem and learned my lesson. Only one clown left in my tank cuz of it.

 

[Hobbes67]

That isn't even long enough for them to get used to the temp change. I keep my fish in the bag for a half hour. I cut a hole in the bag so they can get fresh air. I'd recommend using a QT though. If you don't you can run into issues like ich. I had that problem and learned my lesson. Only one clown left in my tank cuz of it.

They stay in the fish bag for about an hour total time, 15 min. When they arrive, in bag inside of tank, after 15 min. I add water from my tank and leave them in there for 15 more minutes, and I do this for a total of 3 times, plus give or take a few minutes before I pull them out and into my tank. So about an hour. Is that plenty of time.