Fish mysteriously dying

[aqualab]

I have a 20-gal nano with a 20-gal sump and skimmer. I believe there is enough O2 in the water from the skimmer action. Tank has been up and running since August 09. The first fish I bought after the tank cycled was a Picaso clown. Every fish purchased after him has died, some within a week others lasted a month. Most have died though within a week. 2 Wrasse, 3 Dwarf Angels, and a Hawk over the past 3-4 months. Heavy labored breathing with some, others I just found the next day dead. All were eating fine and swimming normally the evening before they were found dead. The clown is fine, the RBTA is fine and a brain is fine. Parameters are good, temp around 79-80, SG 1.025, pH 8.3. I have previously owned 200 gallon, 100 gallon and 90 gallon reefs over the past 10 years or so, never had a problem like this. I have lost more fish mysteriously with this tank then all the others combined. All the fish were purchased from different stores both online and locally. The Mystery Wrasse did have some white blotchyness towards the back end near his doral for a few days before he finally went down, he lasted over a month. No signs of any discoloration on any of the others. The Flame Hawkfish was very pale when I found him in the morning dead, as were several others. ICH?

I have a ventless Empire brand propane wall heater in the same room as the tank (finished basement), possible CO2 levels high enough to affect tank maybe? It is installed to code, unit can be installed in any room other than a bedroom. I am at wits end here, obviously not going to put another fish in until I figure out what is going on and correct the problem. Strange how the little clown is not affected at all. Any ideas, thoughts, help would be appreciated.

Thanks

 

[aqualab]

Ooops, O2 level not CO2 level.

 

[wooden_reefer]

I have a 20-gal nano with a 20-gal sump and skimmer. I believe there is enough O2 in the water from the skimmer action. Tank has been up and running since August 09. The first fish I bought after the tank cycled was a Picaso clown. Every fish purchased after him has died, some within a week others lasted a month. Most have died though within a week. 2 Wrasse, 3 Dwarf Angels, and a Hawk over the past 3-4 months. Heavy labored breathing with some, others I just found the next day dead. All were eating fine and swimming normally the evening before they were found dead. The clown is fine, the RBTA is fine and a brain is fine. Parameters are good, temp around 79-80, SG 1.025, pH 8.3. I have previously owned 200 gallon, 100 gallon and 90 gallon reefs over the past 10 years or so, never had a problem like this. I have lost more fish mysteriously with this tank then all the others combined. All the fish were purchased from different stores both online and locally. The Mystery Wrasse did have some white blotchyness towards the back end near his doral for a few days before he finally went down, he lasted over a month. No signs of any discoloration on any of the others. The Flame Hawkfish was very pale when I found him in the morning dead, as were several others. ICH?

I have a ventless Empire brand propane wall heater in the same room as the tank (finished basement), possible CO2 levels high enough to affect tank maybe? It is installed to code, unit can be installed in any room other than a bedroom. I am at wits end here, obviously not going to put another fish in until I figure out what is going on and correct the problem. Strange how the little clown is not affected at all. Any ideas, thoughts, help would be appreciated.

Thanks

Fish die for many reasons but there should be several basic guarantees that the aquarist has to provide.

First is water quality. Ammonia and nitrite ought to be zero. You said the parameters are good. Have to tested often enough? In general, it is better to take steps to make very certain that there will be no ammonia or nitrite. If you have to test for them really to see if there is none, you are generally not thorough enough. Ammonia could really be a problem from your description. When you have a small bioload for long enough after a cycle, adding new livestock can be a problem. I suggest that you cycle another medium in a separate container and add to your sump and allow return water to run around or drip over it before you add another fish. After QT, in fact, you can use the same medium in QT and then in DT.

Second, don't have too much faith in immunity. You have to reduce the waterborne pathogenic bacteria concentration in the QT and then in DT. For this, I always use UV whenever possible. The sign of ich is consistent but that of bacterial infection varies a lot.

 

[Chris27]

Have you ever left the tank fallow for a period of time longer then 4 weeks? There may be something in there that just needs to work itself out, many ailments need a host to survive, and without one for a period of time it will just die off.