Clownfish Swimming horizontal

[Gunnyreefer]

I hate for my first actual created post to be an issue but I am in need of some assistance. My issue is, I recently purchased several clowns and they are not doing well in my system. I lost 6 storm clownfish of various colors and sizes all displayed the same symptoms. I am currently housing 9 pairs of clownfish in roughly a 120 gallon breeding system. I have a refugium with 50-60 lbs live rock and a pair of target spot mandarins, bright well bio brick a reef octopus regal 250 skimmer, auto top off. I also run air stones in my sump and refugium as I thought it could be a low oxygen issue. Tanks are vacuumed after feeding into a sock which is changed every other day.

Horizontal swimming at varying depths in the tanks
rapid breathing/ gill movement
They all ate well up until they passed away. My pairs of clowns that I have had for up to ten years all of which were introduced to the system with in a couple days are doing great. No visible external issues on any of the clowns that died.

I did do a treatment of prazipro because I noticed a few of the clowns had white stringy poop, I also fed metroplex, kanaplex with focus for a week. No more stringy poop. After the fifth day of the prazi I did a 20 gallon water change put the carbon reactor online and fired the skimmer back up. The next day I did a 15 gallon water change. Its been 7 days since the completion of the prazipro and medicated food.

Temp 78-79 degrees
Nitrate 0
Ammonia 0
Salinity 1.020
10-15 gallons a week water change

I feed a few times a day
LRS Fertility Frenzy
TDO pellets
New life spectrum pellets
Frozen Mysis and Brine (I forget the brand)

 

[Birdbrains?]

Oh that sounds horrible, I am sorry to hear about this! I suppose none of these clowns were wild caught? Idk all the designer names, but storms are tank raised fishes, right?

I guess that swim bladder issues could make them stuck in the horizontal swimmode? Idk if swimbladder issues can happen that quick in a closed environment. It sounds like you are building a big set up so I guess it has been some time since you got all these and they are already acclimatised to the salinity level?

Clownfishes keeps eating until they burst, right?
You sound very experienced, and i guess you didn't overfeed them either?

Did the 6dead ones show no signs? They swam completely normal?
If not, could the 6 first ones have died from another cause than what is causing the abnormal behaviour?

Two separate issues on top of eachother, would make it harder to figure out right away I suppose.