Added a UV filter and fish died overnight.

[Rundown87]

I am not sure if this is the correct area to post this but I have had my tank up and running for a few months and last night I added an in tank uv filter to the sump area of my aio.

This morning i woke up and all of the fish were floating on the bottom. Is this something that anyone else has experienced? I am really devastated as everything was going so well and then this. I haven't had a chance to check the parameters yet as I had an early meeting to get to but the temp was in line where it normally was since starting. I have a magnetic thermometer hanging in the display to check the temp periodically. I also have a GSP frag that is normally always open that was closed up. I had my fiance check the frag when she got home and it was still closed.

I cannot think of what may have caused this. I was thinking of checking to see if there is something that malfunctioned with the uv but wouldn't know what to check.

Anyone have any recommendations on where to start? I am going to break down and clean everything but would like to know what happened here.

Thanks everyone.

 

[Montiman]

It is hard to say for sure what happened, but I would suspect something shorted out in the UV and electrocuted the fish. I have seen this multiple times if the UV quartz sleeve was not sealed properly. I would open the unit and inspect the quartz sleeve for water damage.

 

[lapin]

Temp ?

 

[Rundown87]

Temp was 77 this morning which is normal.

 

[AcanthurusRex]

The fish cannot get electrocuted under any kind of normal conditions.
If the UV is responsible it must have something toxic on it. If there was a leak and the bulb exploded that might be bad. If it did fail be careful as you could get zapped.

 

[Hemmdog]

what brand UV was it.

 

[Montiman]

The fish cannot get electrocuted under any kind of normal conditions.
If the UV is responsible it must have something toxic on it. If there was a leak and the bulb exploded that might be bad. If it did fail be careful as you could get zapped.

Regardless of how the fish died I have seen multiple times where a leaky quartz sleeve allowed water to come in contact with the lamp connector and many fish have died. Technically the tank shouldn't be grounded so the fish aren't electrocuted per say but the stray voltage is not good. This also doesn't seem to effect corals but instead fish.

 

[Rundown87]

what brand UV was it.

Aquatop brand

 

[albano]

Did you clean/wipe down the UV unit before putting it in your sump?

 

[Rundown87]

Did you clean/wipe down the UV unit before putting it in your sump?

I did. All with RODI water

 

[DLHDesign]

I'm sorry for you loss. :-(

I would look for stray voltage in the tank for sure. If you have a voltmeter, it's as simple as setting the voltmeter to AC Volts, putting one meter lead in the water and the other needs to be touched to something grounded, typically the ground plug pin on a nearby receptacle. You should get very close to a 0 reading. If you don't, try turning off equipment one at a time until the reading drops (start with the UV, obviously). Note that multiple devices may be contributing, so it may take shutting down combinations of things to get to a near-zero result.

Aside from that, I would also suggest testing for ammonia in the tank. It's not really likely that running the UV impacted your bacteria population over night (or at all, really), but it's conceptually possible that it had enough of an impact to allow some ammonia to build up which caused a cascade of problems. Some ammonia might be present anyways due to your losses, so a positive result won't be conclusive, but a near-zero result should indicate that your bacteria population is still present (and thus not likely to be a factor for this event).

 

[AcanthurusRex]

Don't waste time on stray voltage either.
Check the unit to make sure it's not broken. If the bulb is broken it might be possible for mercury to escape but I think it will just collect somewhere. Even if it broke I don't think mercury is acutely toxic.
Do a big water change. Run some carbon. Maybe use something like polyfilter as well.
I have a UV on my tanks. Never really thought about the contents of the bulb poisoning the tank.

 

[S.Pepper]

Sorry, I can't offer any help, but I feel your pain.