my filtration

You should be able to have more than 1 fish with that HOB. I have one on my tank and have 2 in a 20g so you would have just as much filtration and more room so you should be able to have more than that even. I would be curious in the fish themselves. How long can you keep one alone alive? Is it a long time where he/she is obviously established and happy? Are the new fish you are getting from a reliable source? Any signs of illness before or on the day of purchase? I don't really know anything about saltwater fish illnesses but you have a good skimmer and the water is obviously good since you are growing corals well. If it were me, I would see if any of your fish were/are sick before you add them to the tank.

Good luck!

 

Hmmm... I'm not sure then. Aquatic Environments is an excellent store and I would trust any of their fish. Sorry I couldn't help out more. Hopefully gered or aj or someone will be able to help with more experience.

 

Have you tested your water? What are your water parameters? How long has your tank been up and running?

--AJ

 

What do you have for coral? Some corals can and do eat small fish. I use to have a bubble coral that killed ate fish all the time.

 

You should be fine..not sure why stuff is dying. What are you feeding?

--AJ

 

Do you have sand in your tank? What's your alkalinity?

--AJ

 

You said every time you add new fish they die right? How long have you been adding new fish? I hope you haven't gone through too many new additions to the tank in the 1.5 months it's been up. Most saltwater tanks take at least a month before they would be considered safe to add any fish. Also, you said "my coral seem to grow so well i can almost sit here and see it grow in front of me." It's pretty cool that you've seen that much growth in less than 2 months. How much growth do you think you've had?

Side note, biowheel filters are not a good idea in saltwater tanks. They buildup and release nitrates very quickly if you don't change out the filter pad every month or so. Every book or article I've read on them in saltwater says they are a no-no. This is totally up to you, just my opinion.

Good luck with new fish in the future, I hope this doesn't discourage you to keep a saltwater tank.

 

I have seen a few tanks fully stocked within a month (not that I recommend it) and they did just fine. Took owners more water changes to get levels to balance. Do you have any aptasia? i have seen two fish go to their deaths when caught by a few heads. sometimes ive found aptasia living in small dark caves where little fish like to hang out.

 

Do you check your levels right after you put in a new fish? Ive seen new tanks like yours go through "mini" cycles that spike and drop within days of adding new fish.
-Box

 

You should listen to your buddies, sounds like they know a thing or two /DesktopModules/ActiveForums/themes/_default/emoticons/wink.gif  In general, canister filters and HOB biowheel filters aren't used in SW set-ups, at least not long-term.  They tend to generate nitrates........invest in a better skimmer instead and more live rock or a sump with live rock and macro algae.
As for your fish dying, how are you acclimating them to your tank?  Do you acclimate for temp?  Do you drip acclimate them?  How do they act after you've released them into the tank?  Do they hide?  Swim near the surface?  Respirate quickly etc?  There has to be more to this picture your painting here, some details must me going overlooked........

 

Easy enough to tell if its cycling again......check if you have any ammonia.

 

Floating the bags for an hour seems a little long to me.  Just float the bags to get the temps the same......the water in the bag will likely be pretty close to the tank temp.  I usually float a bag for 15-20 minutes tops, especially if I just got it from a pet shop.  If it was a shipped item, maybe 30 minutes.  I also drip acclimate all SW fish and especially SW inverts.  Maybe its not necessary for all marine fish, but that's what I do.  Fosters and smith does have a nice little drip acclimation kit for like $2 /DesktopModules/ActiveForums/themes/_default/emoticons/smile.gif
Drip acclimation (scroll down)