have a bit of a big issue in our shark display at the hotel. as we mentioned we took over the maintenance of this 70.000lt shark display with 3 (about 6 year old BTRS) as the aquarium was build with maintenance being a lowest priority withclose to no access to the display we needed to start cleaning the system. 3 days ago we cleaned up the Sump. the sump is huge with a 10.000lt volume. so we removed everything out of there and gave it a good clean. no chemicals or anything used just a good scrub down. we used this in one tome as a 10.000lt water change.
now 3 days later we have one shark lying on the floor barely breathing. the 2 others have red marks on their belly and fins but seem to be breathing fine and swimming around. we went straight in a 50% water change mode and removed the worse shark placing him in large basin trying to get him to move and breath which worked a bit at the start but he eventually died.
the 2 other Sharks still swimming normal.....msee pictures attached
all parameters from tank tested ok with just Nitrates up....
anyone has any theories?
now 3 days later we have one shark lying on the floor barely breathing. the 2 others have red marks on their belly and fins but seem to be breathing fine and swimming around. we went straight in a 50% water change mode and removed the worse shark placing him in large basin trying to get him to move and breath which worked a bit at the start but he eventually died.
the 2 other Sharks still swimming normal.....msee pictures attached
all parameters from tank tested ok with just Nitrates up....
anyone has any theories?