I came home from work and went to feed my fish and found my bristletooth and scopas dead on the substrate. All my fish were seemingly doing very well even last night. They were all very active and eating everytime I'd feed the tank, and I fed pretty often so I know they didn't starve. They all got along nicely. I had no concerns whatsoever. I've been following the 4 month recommended BRS guide to biome cycling my tank for coral. It's been one month so far and I've added two clowns, a bristletooth tang, a scopas tang, a melanarus wrasse and a starry blenny. Each fish added individually except the clowns, and each drip acclimated and added after verifying nitrites and ammonia were undectable with unexpired api test kits. All the other fish are still fine. Just the two tangs. I removed the dead tangs and tested the water immediately.
API Ammonia: 0 ppm
API Nirtite: 0 ppm
Hanna Nirtate: 24.7 ppm
Hanna Alk: 7.7 dkh
Temp: 78 F
Salinity: 1.024
My tank is an IM 50 lagoon AIO fusion pro 2.
The tangs were still juveniles and were going to be transferred to a bigger tank in the future. My initial thoughts after doing some research are low O2 levels. I'm just not sold on that though since I have two spin stream nozzles attached to the return lines which agitate the surface pretty good, but I may be overestimating their gas exchange ability. I unfortunately cannot test for O2, but have since added a tunze comline skimmer to the rear chamber. I just don't know what else it could be. The other fish are just fine and it has me so confused. No gasping as the surface, everyone is still eating when I feed. I'm going to be doing a 15 gallon water change tonight regardless. I really thought things were going very well for the tank and now I'm unsure and don't want to add anything to it until I'm sold on what the issue was. Please provide solid opinions and/or fact based constructive criticism and thank you for taking the time to read.
API Ammonia: 0 ppm
API Nirtite: 0 ppm
Hanna Nirtate: 24.7 ppm
Hanna Alk: 7.7 dkh
Temp: 78 F
Salinity: 1.024
My tank is an IM 50 lagoon AIO fusion pro 2.
The tangs were still juveniles and were going to be transferred to a bigger tank in the future. My initial thoughts after doing some research are low O2 levels. I'm just not sold on that though since I have two spin stream nozzles attached to the return lines which agitate the surface pretty good, but I may be overestimating their gas exchange ability. I unfortunately cannot test for O2, but have since added a tunze comline skimmer to the rear chamber. I just don't know what else it could be. The other fish are just fine and it has me so confused. No gasping as the surface, everyone is still eating when I feed. I'm going to be doing a 15 gallon water change tonight regardless. I really thought things were going very well for the tank and now I'm unsure and don't want to add anything to it until I'm sold on what the issue was. Please provide solid opinions and/or fact based constructive criticism and thank you for taking the time to read.