Most fish dead expect Banggai Cardinalfish

[MysticSea]

As the title says came home yesterday to all fish dead expect my paired Cardinalfish...my corals and other invertebrates are doing fine and tested the water quality.

pH: 8.4
Alkalinity: 9 dKh
Calcium: 450 ppm
Magnesium: 1350 ppm
Nitrates: 0 ppm
Phosphates: 0 ppm

The tank is a 25 five gallon cube and here "was" my other tankmates...

Mandarin Dragonet
Paired Clownfish
Sailfin Blenny

So like could my Cardinalfish have killed my other fish for territory or what? I am very disappointed because my LFS said they would be great for my tank. Give me your thoughts?

 

[Bfragale]

For a mass death event sounds like something other then aggression.

My first thought is low oxygen. Are you running a skimmer? Have you made any recent changes? Any bacteria bloom or something like that that could possible consume the oxygen?

Does the cardinal look to be breathing heavy?

 

[MysticSea]

For a mass death event sounds like something other then aggression.

My first thought is low oxygen. Are you running a skimmer? Have you made any recent changes? Any bacteria bloom or something like that that could possible consume the oxygen?

Does the cardinal look to be breathing heavy?

No its definitely not O2 related because they are acting normal and I grow about 3-4 pounds of macroalgae along with two powerheads. Its just weird because everything else is doing fine

 

[mike550]

@MysticSea could it be chemical or aerosol ?

 

[USMC 4 LIFE]

Can you add a picture of your tank. Maybe we’ll notice something off or concerning.

 

[Garf]

Has your algae crashed?

 

[MysticSea]

Has your algae crashed?

Nope macroalgae is fine which again is weird how most things are fine.

 

[MysticSea]

Can you add a picture of your tank. Maybe we’ll notice something off or concerning.

Yes once the lights come on I will show a recent picture.