1 fish dead, 1 fish missing

[Coralgurl]

Ammonia is 0 on salifert test. It's at 1 on the API test. Water is mixing, will do a change in an hour or so.

The royal gramma came out 5 mins ago so it's just the clown and hawkfish.

I've had an issue with my skimmer, had a snail caught in the intake. I took it apart, cleaned it but it wouldn't stop over flowing, so I left the plug out and just let it run. It finally stopped last night. I do use filter socks and kept them on during this time. Checked the flow on the return pump, it was reduced, the intake was clogged with cheato, cleaned off and it's running fine.

Last water change was 2 weeks ago before I left on holidays. Tank was looked after while I was away, as the weather was cool, was not worried about the temps. Top ups done and fish were fed.

I'm not sure what I could have done or not done to cause these deaths

[Coralgurl]

Unless you find your missing fish the problem is likely a lack of oxygen event that caused some of your fish to die. Interesting... this may seem like a dumb question, but how would I check this? I have my returns pointed at the water surface and 4 powerheads, all working.
Alternatively, you can be experiencing a cycle. You should check your parameters. Will check when I get home.
Alternatively, you may have had a temperature spike. Possible - wouldn't this affect more fish? I unplugged my heaters before I left the house this morning simply because its supposed to be fairly warm today. My tank has been hovering around 81.5 over the summer.

It is doubtful that anything in your tank attacked, killed and ate two fish and killed and partially ate the other in one evening.Well it is Shark Week........[/quote]

[naesco]

Originally Posted by Coralgurl

Unless you find your missing fish the problem is likely a lack of oxygen event that caused some of your fish to die. Interesting... this may seem like a dumb question, but how would I check this? I have my returns pointed at the water surface and 4 powerheads, all working.
Alternatively, you can be experiencing a cycle. You should check your parameters. Will check when I get home.
Alternatively, you may have had a temperature spike. Possible - wouldn't this affect more fish? I unplugged my heaters before I left the house this morning simply because its supposed to be fairly warm today. My tank has been hovering around 81.5 over the summer.

It is doubtful that anything in your tank attacked, killed and ate two fish and killed and partially ate the other in one evening.Well it is Shark Week........

[/quote]

On the oxygen and temperature and even ammonia issues different fish react differently. Some will die immediately others will hang in there enough to allow you to oxygenate the water or to correct the problem That is why some are still alive.

81.5 is not a problem at all but while you were out if it spiked to 84 or 85 it could be a cause of the problem. Opening the doors to the sump area and a cheap $29.00 pedestal fan will really help.

There are oxygen test kits but I have never used them.
All I know is that if you have mulitple fish deaths in one day it is often lack of oxygen, a serious ammonia spike, or overheating that is the likely problem.

[Coralgurl]

I will post my findings when I get home! Thanks for the advice!