New Canister Filter issue

[ttruax75]

Hello,
I'm new to this site and looking for help. I have a 75 gallon fish only saltwater tank. I had a filter that just hooked on the back of the tank for 3 years. I was looking to upgrade and got a canister filter system and installed it on Saturday. When I installed the system, there was a 9 watt UV in the canister that leaked within a few hours and shorted out. I turned the UV off and all seemed okay. I've had my hands in the water several times after with no issues of getting zapped. I had a 36 watt UV in there for a few years but it burned out a while ago. I just replaced the UV that burned out with one yesterday , 13 watt, situated under the return from my new canister filter return. I had around 7 fish in there foxface, small tang, valentini puffer, 2 cardinal fish, and a clown. Everyone seemed to be happy and I've had all of them in there for a minimum of 2.5 years. I woke up this morning and all but my clown were either already dead or were shortly after I found everyone. I checked the temp and water was a bit elevated ~78 degrees so I added a cooler RO water. I checked my chems and nothing has changed there. My salinity is spot on. Any advise on what's going on would be great. Thank you.

 

[ttruax75]

Hello. I'm new to this thread. I've had my tank for close to 3 years with no issues. It's a fish only tank 75 gallon with live rock. Thank has a protein skimmer too. When I set it up I just put a standard Marineland bio dual filter. I decided to upgrade and installed a canister filter on Saturday. This filter system had a 9 watt UV sterilizer that leaked and shorted out within a few hours of install. I checked the inside of the canister to make sure all was okay and it was so I flipped the button to off and left it alone. I had a 36 watt UV in the tank for about 2.5 yrs but it burned out. I got a 13 watt yesterday and installed it under the water return. I had 7 fish in the tank, Foxface, Valentini Puffer, 2 Cardinals, Tang, Clownfish. I've had them all for about the same amount of time (within a few months) I've had the tank after it cycled. Chem and salinity have been fine. I got up this morning and between last night and this morning all have died except for the Clown. Temp was a bit elevated (~78 degrees) so I added some cold RO water and dropped it a few degrees. Checked chems and salinity and they are still fine. Help! From reading articles it looks like maybe the natural bacteria flora was killed off but any advise would be great! Thank you much.

 

[dadnjesse]

Sounds like when you replaced that filter you disrupted the bacteria that was keeping the tank ammonia stable. Do you check the Ammonia levels.

 

[ttruax75]

Thank you for your reply. Yes I checked the ammonia this morning and it was 0 ppm. PH, Nitrate, and Nitrite were all fine too. I added Remediation bacteria this morning just in case. Any advise and ideas at this point is welcome.