Fish die immediately

Question
I have a newly setup 90 gallon saltwater tank (one week). I have 10lbs of live rock and 90lbs of AragaMax Aragonite based live sand in it.
My ph is at 7.8
ammonia is not present
nitrates and nitrites readings are nominal.
specific gravity is at 1.022.
I have not added a protein skimmer yet.
Rena XP3 canister filter with biostars, activated carbon and varying sponge filters (all at rates for 90 gallon tank).
one powerhead producing 160gp flow.

I added three damsels to aid in the cycle process at day 6, one of which immediately acted like it had no balance, swam upside down most of the time and let the current push it around and the other two acted fine but all three died that night. I added one damsel the next day and it immediately start swimming at the top and went to the bottom in less than 5 minutes. It died less than 30 minutes after laying on the bottom for most of that time. I had one crab crawl out of the live rock and it died also.

It almost seems as if there is something toxic in the water but I do not know where it could have come from.

Any suggestions would be greatly appreciated.

Answer
Hi David. I am sorry to hear about your problem. I can tell you it can be a little frustrating when things like this happen. First of all I want to look into your water source. What water did you use? Was it municipal water , well water or did you use high quality water like distilled or reverse osmosis? There are a lot of chemicals that can come in when using city water supplies as well as well water. You should always use distilled or R.O. to ensure that none of these chemicals accidentally enter your tank. Next would be your acclimation procedure. Are you acclimating using a drip or shot glass method for a minimum of 20 min. to no longer than 40 min.? Too long of an acclimation period can be just as detrimental to your fish as not doing it at all. Now lets look at how turbulent your water may be. A fish coming into a new environment is already stressed out and may be a little weak. If your water is too turbulent than it may have to work harder to swim and that can tire out the fish, stress it out more, and cause it to become weak and die. Is there any way a toxic substance could have entered your tank? Toxins can enter your tank through aerosol sprays, smoke, substances on your hands and by accidentally falling into the tank. Is this a possibility? Also did you rinse out your tank before you set it up? I was in a pet store once and actually saw an employee using endust to clean out the tank! Very true and very disturbing. Did you use any detergents to clean out your tank before you set it up? You should never use soap to clean any equipment that is going to be used in a saltwater tank. Was your tank new or did you buy it used? If new thats great but when buying a used system you may never know what was in there before you got it or what was used to clean it out. Lastly take a good look at where you purchased your fish. It may be as simple as the store you got them from selling less than quality animals and you may want to try a different source. I hope I have given you some direction in which to look and find an answer. Sometimes you get many fish and they just keep dying for no apparent reason and then all of a sudden you buy one it lives and you never have any more problems and you never truly know the reason why so many fish died in your tank. Good luck and if you have any more questions please feel free to ask!