Lost Almost Half My Fish Overnight And I Dont Know Why

Discussion in 'Saltwater Fish Disease' started by Eretreia, Mar 28, 2019.

  1. EretreiaNew MemberMember

    Hi guys, Eretreia here. I have a 90Gal reef tank. I recently (more than two months ago) moved my 55G into it for more room.
    Equipment on tank:
    Eheim 2217
    1 pump with remote conroller
    1 HOB reef octopus skimmer
    1 coral rated light (don't remember the brand; wifi controlled)
    I have and have had for a while:
    4 hammer corals, mushrooms, galaxea, buttons, etc
    As for fish, I have (including the ones i just lost): 1 bicolor blenny, 1 pygmy angel (dead), 1 six line wrasse (dead), 1 mimic tang (really weak), 1 midas blenny, and 1 flame hawk (dead), along with 2 cleaner shrimp, 1 peppermint, 1 sea urchin, 2 sea stars, and some crabs and snails.

    Water test was done last night and nitrates, nitrites, and ammonia tested at 0ppm. We have been treating the tank with prazipro for 7 days because we noticed that some of the fish were breathing fast, but they were all eating really well, and their colors were bright as usual. After one week of prazipro, they were still breathing fast, but now more of them were doing it, but they were still eating and looking good. Then, all of a sudden, this morning I woke up to three of them dead, the water slightly cloudy and the rest of them looking pretty bad. It wasn't even difficult to catch them as they are too weak to try and escape. I don't think the mimic tang or the bicolor blenny is going to make it, but I have absolutely no idea what happened! If any of you guys have any experience with this or any kind of insight, please share!

    PS: I removed all the fish from the tank, gave them a freshwater dip, then put them in RO saltwater in a separate tank. Same with the shrimp (one of which even has eggs ;-; ). Also, there was nothing on the dead fishes' bodies to indicate any kind of sickness at all, and nothing on the ones that are still alive either. Just really fast breathing.
  2. JesterraceWell Known MemberMember

    What were the salinity levels of your tank?
  3. EretreiaNew MemberMember

    The salinity showed 32 last night, so I added a couple of gal of RO and now is at 30.
    After 2 15 min long freshwater dips the survivors were still with us; so we moved them in a QT. There was nothing on their bodies last night, we checked with a flashlight and a magnifier, skin looked perfectly clean, fast breathing being the only issue. Also, the flame hawkfish looked pale and was hiding under the rocks, so I couldn't check him, but they all eat and were even fighting over the food. We have no clue why they died in less than 24 hours. :((
  4. coralbanditWell Known MemberMember

    Have you been adding the prazi everyday for the last 7 days ?
  5. AvalancheDaveWell Known MemberMember

  6. EretreiaNew MemberMember

    Prazi every day? No... First dose on the 21st and the second on the 26th. I use RO with salt from the fish store. The good news is that the survivors are still alive, in a QT. I I just noticed a tiny little feather duster worm in the display tank that is still alive, and I did not believe it would survive the treatment (I could not remove it from the tank because it was growing on a live rock), and I am wondering now if the Prazipro worked... It says on the bottle that it kills the worms
    Last edited: Mar 30, 2019
  7. JesterraceWell Known MemberMember

    Salinity levels seem a bit light unless you are talking about an sg of 1.032 or 1.030 (in which case it's definitely uncomfortable for fish). Then again if you are going with lower salinity levels for possible parasite issues in QT that might make sense. Ideally an SG of 1.024-1.026 is where you want to b for a mix of fish and corals.