Help figure out what is causing fish deaths

[northstarsentinel]

I've had a string of random fish deaths in my tank and I don't really know what is happening. Any input is greatly appreciated!

Deaths: I've had 1 molly and 1 longnose hawkfish disappear, they are presumed dead since I have not seen them in weeks, but I never found a body for either of them. I had one pajama cardinal die overnight, and just this morning I had a pajama cardinal erratically swim for a few seconds until they hit the side of the tank and died on impact (I saw it happen). So 4 fish in 1 month.

Here are the stats:

• pH = 7.8
• nitrates and nitrites = 0
• ammonia = 0
• salinity = 1.28
• 120 gallon tank I have had setup for just over a year now. The cardinals were some of the first fish I got, so I've had them for over a year now too.
• The tank has mesh lids handmade by me to fit with no gaps.
• It's a soft coral tank with a small handful of lps and is a community tank with peaceful fish.
• I feed them a mix of frozen, pellet and algae sheets. They are fed every other day.
• The two bodies I did see - the cardinals - had no visible damage or injuries. They looked healthy with full color and behaved normally right up until their death. (from what I can tell, I am no fish whisperer)

The tank does have an aptaisia outbreak right now, I just find it hard to believe that aptaisia would kill so many fish.

Thank you so much for any help this has been quite depressing.

 

[Lavey29]

What other fish are currently in the tank? Have you checked for stray voltage? When was the last time a new fish was added? The erratic swimming followed by hitting the glass seems like it was scared of a predator in the tank.

 

[vetteguy53081]

I've had a string of random fish deaths in my tank and I don't really know what is happening. Any input is greatly appreciated!

Deaths: I've had 1 molly and 1 longnose hawkfish disappear, they are presumed dead since I have not seen them in weeks, but I never found a body for either of them. I had one pajama cardinal die overnight, and just this morning I had a pajama cardinal erratically swim for a few seconds until they hit the side of the tank and died on impact (I saw it happen). So 4 fish in 1 month.

Here are the stats:

• pH = 7.8
• nitrates and nitrites = 0
• ammonia = 0
• salinity = 1.28
• 120 gallon tank I have had setup for just over a year now. The cardinals were some of the first fish I got, so I've had them for over a year now too.
• The tank has mesh lids handmade by me to fit with no gaps.
• It's a soft coral tank with a small handful of lps and is a community tank with peaceful fish.
• I feed them a mix of frozen, pellet and algae sheets. They are fed every other day.
• The two bodies I did see - the cardinals - had no visible damage or injuries. They looked healthy with full color and behaved normally right up until their death. (from what I can tell, I am no fish whisperer)

The tank does have an aptaisia outbreak right now, I just find it hard to believe that aptaisia would kill so many fish.

Thank you so much for any help this has been quite depressing.

While they shouldnt, these things happen. Has there been any change in water used or water source?
How are you testing your water levels?
Any signs of heavy breathing prior to discovery? Also any erratic swim behavior?
Were the mouths open when you discovered the dead fish?
Is heater intact, and not broken?

 

[northstarsentinel]

What other fish are currently in the tank? Have you checked for stray voltage? When was the last time a new fish was added? The erratic swimming followed by hitting the glass seems like it was scared of a predator in the tank.

I tried to keep it to only peaceful fish. I have 6 female mollies, 1 other pajama cardinal, 2 zebra gobies, a fire fish, a royal gramma, a scopas tang, a yellow coral goby and a bi-color blenny. I have not added a new fish or coral for a few months now.

I haven't checked for stray voltage, I'll look into how to check for that. Thanks for the suggestion!

While they shouldnt, these things happen. Has there been any change in water used or water source?
How are you testing your water levels?
Any signs of heavy breathing prior to discovery? Also any erratic swim behavior?
Were the mouths open when you discovered the dead fish?
Is heater intact, and not broken?

I'm testing my water levels using the API test kit (not the strips), which I know is not the preferred way. I can take my water in to my LFS to have them test it and double check my test kits are reading correctly.

I did not notice any strange swim behavior or erratic breathing from these fish. The cardinal that died over night had it's mouth open when I found it but it was the only one. There are two heaters in the SUMP that are both in tact as far as I know, the temperature on a separate thermometer corroborates it is at the expected temperature, they are less than a year old.

Thanks for the help, these are food things to check for.

 

[northstarsentinel]

GOOD NEWS, the cardinal that I thought died this morning woke up??? They hit the glass and I guess passed out, but she stopped moving and breathing. Not even a twitch of movement for 20+ minutes. I just looked at the tank again and they're up and swimming again.

 

[landlubber]

any particular reason you keep your salinity at 1.28 and not 1.26?
I don't suspect that'd be the reason for fish mortality but its not hard to hold the proper value.
Also not relative to your fish but asking for issues is your unreadable levels of nutrients. Nutrients are one of the sources corals feed from meaning your sterile tank is holding them back along with swinging the door wide open to bigger issues like Dinos.

 

[vetteguy53081]

I tried to keep it to only peaceful fish. I have 6 female mollies, 1 other pajama cardinal, 2 zebra gobies, a fire fish, a royal gramma, a scopas tang, a yellow coral goby and a bi-color blenny. I have not added a new fish or coral for a few months now.

I haven't checked for stray voltage, I'll look into how to check for that. Thanks for the suggestion!


I'm testing my water levels using the API test kit (not the strips), which I know is not the preferred way. I can take my water in to my LFS to have them test it and double check my test kits are reading correctly.

I did not notice any strange swim behavior or erratic breathing from these fish. The cardinal that died over night had it's mouth open when I found it but it was the only one. There are two heaters in the SUMP that are both in tact as far as I know, the temperature on a separate thermometer corroborates it is at the expected temperature, they are less than a year old.

Thanks for the help, these are food things to check for.

Yes , get a test for comparison and have a store that does Not use API tests do this. I recommend salifert or hanna brand. In addition assure temp is in range of 76-79 and take salinity to 1.026 although 1.028 would not ne a cause. Any inverts in tanks such as snails or shrimp, and how do they look?

 

[Lavey29]

Just my .02 but royal gramma can be aggressive and the scopes tank zipping around may have stressed the cardinal too.

 

[northstarsentinel]

any particular reason you keep your salinity at 1.28 and not 1.26?
I don't suspect that'd be the reason for fish mortality but its not hard to hold the proper value.
Also not relative to your fish but asking for issues is your unreadable levels of nutrients. Nutrients are one of the sources corals feed from meaning your sterile tank is holding them back along with swinging the door wide open to bigger issues like Dinos.

I do not have a specific reason for keeping it at 1.28, I can lower it to 1.26.

I agree the nutrients are very low, I had a hard time getting them higher though. Is it just a matter of feeding more often? I don't run a protein skimmer / refugium / reactors, the only thing in the sump is extra rock / bioballs / filter media.

Yes , get a test for comparison and have a store that does Not use API tests do this. I recommend salifert or hanna brand. In addition assure temp is in range of 76-79 and take salinity to 1.026 although 1.028 would not ne a cause. Any inverts in tanks such as snails or shrimp, and how do they look?

I'll go to the store and have them check it and look into getting better water testing kits. Just checked the temp and it's at 78. No shrimp, but I do have hermit crabs and snails. The ones I see are moving around and eating things as per usual or are buried in the sand as per usual. I did find 2 red hermit crab shells in the sand in the past month, I could not tell if they were molts or dead hermit crabs. I also suspect the hermit crabs have eaten some of the non-burrowing snails.

Just my .02 but royal gramma can be aggressive and the scopes tank zipping around may have stressed the cardinal too.

I have seen the royal gramma swim after other fish, and you're right the scopas zips around a lot. Is it not recommended to keep them together with community fish?

 

[northstarsentinel]

Here's pictures of the fish, someone in another forum asked for them.
Fish that almost died:

Other cardinal:

Other members of the tank:

 

[vetteguy53081]

Here's pictures of the fish, someone in another forum asked for them.
Fish that almost died:

Other cardinal:

Other members of the tank:

With the inverts doing well . it does then eliminate water quality and points to disease. One thing the fish in pics have in common is their susceptibility to flukes. Some signs if they have it will be red or swollen gills with rapid breathing, fish acting lethargic or swimming near the water surface, hiding in the corner of tank or behind rocks, loss of appetite, shaking its head, flashing/darting, develop clamped fins, , or scratching against objects. They may also exhibit what looks like yawning from gill irritation develop, cloudy eyes and loss of color.

 

[northstarsentinel]

With the inverts doing well . it does then eliminate water quality and points to disease. One thing the fish in pics have in common is their susceptibility to flukes. Some signs if they have it will be red or swollen gills with rapid breathing, fish acting lethargic or swimming near the water surface, hiding in the corner of tank or behind rocks, loss of appetite, shaking its head, flashing/darting, develop clamped fins, , or scratching against objects. They may also exhibit what looks like yawning from gill irritation develop, cloudy eyes and loss of color.

Thanks for the callout! I have noticed some of these symptoms in the fish. I looked up some treatment options and will go get PraziPro to treat the entire tank.

 

[vetteguy53081]

Thanks for the callout! I have noticed some of these symptoms in the fish. I looked up some treatment options and will go get PraziPro to treat the entire tank.

With Prazi, to be safe , dose at 85% of recommended and apply initial dosage known as an interval for 8 days, do a water change and do one more 8 day dose interval
Use airstone with prazi as it does reduce both oxygen and appetite. If running a skimmer, leave cup off first 24 hrs as skimmer will go nuts from the glycol solution in Prazi

 

[Jay Hemdal]

I tried to keep it to only peaceful fish. I have 6 female mollies, 1 other pajama cardinal, 2 zebra gobies, a fire fish, a royal gramma, a scopas tang, a yellow coral goby and a bi-color blenny. I have not added a new fish or coral for a few months now.

I haven't checked for stray voltage, I'll look into how to check for that. Thanks for the suggestion!


I'm testing my water levels using the API test kit (not the strips), which I know is not the preferred way. I can take my water in to my LFS to have them test it and double check my test kits are reading correctly.

I did not notice any strange swim behavior or erratic breathing from these fish. The cardinal that died over night had it's mouth open when I found it but it was the only one. There are two heaters in the SUMP that are both in tact as far as I know, the temperature on a separate thermometer corroborates it is at the expected temperature, they are less than a year old.

Thanks for the help, these are food things to check for.

Stray voltage produced by induction of water pumps etc., will not harm your fish, it’s a literal red herring. Short circuits to ground can be dangerous for fish and yourself.

It’s possible/probable that there isn’t a common cause for these fish losses - that makes any diagnosis incomplete.

I’ve found the best thing to do in these cases is to carefully evaluate the remaining fish - look for scratching/flashing, rapid breathing, poor coloration, poor appetite, etc.

 

[landlubber]

I do not have a specific reason for keeping it at 1.28, I can lower it to 1.26.

I agree the nutrients are very low, I had a hard time getting them higher though. Is it just a matter of feeding more often? I don't run a protein skimmer / refugium / reactors, the only thing in the sump is extra rock / bioballs / filter media.

Your options for raising nutrients are to feed more or to treat yourself and add fish to the system.
I read your tank is celebrating its first anniversary since it's startup which means all that liverock in the display and sump are likely biologically running at full capacity and process waste well.
One other tweak you might consider is incrementally removing the bioballs. While they're great in a freshwater system our liverock serves essentially the same purpose without the caveat of trapping detritus like the balls tend to do if you're not occasionally rinsing them off.