Trouble in our tank

[JRP]

Hope someone can help. We have a 55 gal. fish only aquarium and have been losing a lot of fish lately. Started our tank last March, and all our levels are good, we check almost every day. Presently we have 1 Foxface Rabbit, 1 Bangai Cardinal, 1 Green Chromi, 1 Sailfin Tang, 1 Yellow Tail Blue Damsel, several Emerald Crabs, 2 Coral banded Shrimp, 2 Chocolate Starfish, and some snails.

Bio wheel filtration, protein skimmer and UV sterilizer.

4 days ago we added a Kole Tang and a Flame Angel, both died. In the last everal months we have lost 3 Yellow Tangs, Bicolor Ange,l Purple firefish, Bangai Cardinal, Dragon Wrasse, Emerald Crab, Turbo Snails, Flame Angel, Long Nose Hawkfish, Green Chromis, Firefish Goby, Yellow Tail Blue Damsel, Goldenhead Goby, Ocellaris Clowns.

They have not all been in the tank at the same time, when a fish or two die we replace with one or two new ones. We did have two Tomato Clowns and were told they may been stressing out some of the other fish, but we removed them 3 weeks ago and we are still losing new fish.

We have been doing water changes every 2 weeks sometime sooner, changing and cleaning filters every 2 weeks. Tank is crystal clear, we have crushed coral base.

we are doing something wrong but don't know what, any help would be appreciated.

Thanks
Jim

 

[nautical_nathaniel]

We're gonna need water parameter values before we can get much further with figuring out what is going on.

What is the span of time in between additions. That is a heck of a lot of fish going in and out of a 55 gallon.

55 gallon reefs are very similar to nano reefs, especially when using a HOB filter, they experience the same sort of rapid fluctuations in water parameters when you make sudden changes, such as adding a new fish. It's likely that you've had ammonia/nitrate spikes with each addition and when the fish die it adds even more stress to the system.

When I lose a fish, I wait a minimum of 2 months before adding anything else. That gives me enough time to figure out if it was something simple like stress that killed the fish or something more serious like ich or marine velvet. That's why quarantine systems are so important for aquariums.

Also, as a friendly warning and not trying to come across as being too snoody, tangs don't belong in a 55 gallon, there's not enough room in there for them to grow and be active.

 

[leahfiish]

A few questions that will help us give you better advice:
Where are you purchasing fish from and are you quarantining them?
Have you noticed any symptoms such as heavy breathing, loss of appetite hiding all the time scratching on rocks?
How quickly are these fish dieing after adding them?
When you say your parameters are fine, what are they exactly? Ammonia, nitrite, nitrate, pH, salinity, temperature?

My initial thoughts are that it's a combination of disease and aggression. Damselfish can be very aggressive to other fish, even ones much bigger than them and tangs are aggressive towards other tangs.
Firefish and cardinals are usually very peaceful and can easily be bullied or stressed by more boisterous or aggressive fish.
With the info you gave, my advice going forward is to quarantine your next purchases for at least 3-4 weeks to ensure they are healthy before introducing them. You can also set up your qt to match your supplier's parameters (salinity mostly) and slowly acclimate them to your display water over a few weeks. During that time, spend at least 5 minutes a day observing your fish for any signs of disease or stress. When it's time to introduce the new fish, use an acclimation box.