What is killing my fish?!

[Jnharris22]

I have a 75 gallon reef tank that is about two months old and I have had no problems up until now and I have lost three (maybe four) fish in the last four days.

Fish lost:

1 orchid dottyback - I had this fish for about six months and it always did well with tank changes as I've upgraded in size and it also seemed to do great through nitrate and nitrite spikes as my tanks have gone through their cycle.

1 blue damsel - this one was most shocking as I've had this fish for a few months and he was always one of my heartiest eaters.

1 golden banded butterfly - this was only about a week and a half into the tank and I couldn't get him to eat frozen foods so unfortunately I think his death had to do with him not acclimating to the new tank very well.

1 blue tang (this is a maybe as I haven't located him yet or actually seen him dead but I cannot find him)

Water Parameters
75g display tank
40g sump with protein skimmer and refugium

Ph= 8.1
Nitrite= 0ppm
Nitrate= 0ppm
Ammonia= 0ppm
Phosphate= 0ppm
KH= 8 degrees / 140ppm
Calcium= 440ppm

Other tank inhabitants:
1 head of toxic green hammer euphyllia

2 heads frog spawn euphyllia

2 heads branching torch euphyllia

1 yellow tang

1 maroon clown

1 orange clown

1 1.5" Green crab

1 cleaner shrimp

5 medium sized hermit crabs

1 sand sifter starfish

1 small acrophyllia

1 superman Cyphastrea

2 heads of green candy cane coral

1 small frag of green star pollup

75lbs live rock

White sand substrate



I would have expected high phosphates or ammonia but neither were found and I did double check each test to be sure. I also expected my corals to suffer before my fish did but it seems to be backwards. Any ideas what could be happening to cause my fish to die? The fish who have died have not had broken or cut up fins or anything that would lead me to believe they were killed off by another tank inhabitant. Please help, any and all suggestions are welcome!

 

[ZoaCollector]

Possibly internal infection, nitrofurazone is good for treating fish that are sick. If it's parasitic you need to treat for that also.
Prazi pro is good for internal worms and flukes.
The butterfly was already sick if he wasn't eating.

 

[madtownguy]

Could be mantis shrimp or large worm caught a ride in live rock, I had that happen once and was puzzled for about 4-5 fish deaths. Both tend to come out at night.

 

[twilliard]

I am going to say stress.
do you QT your fish ?

 

[Harold Green]

I'd remove the fish you have left and put them in a quarantine tank. If they recover it's a tank issue. It can be pretty difficult to pinpoint a problem when your testing doesn't show an issue. If the shrimp is doing well I would suspect it isn't a tank problem but a disease or something killing your fish.

 

[twilliard]

The tank is very young.
that within itself can be an issue.
0 nitrates??
Stuff will be coming up so slow it down a little

 

[dmh41532]

Since fish died after you added the butterfly, im the thinking its some type of disease. I would catch the fish and move them to a quarantine tank. Maybe some internal infection or parasite?

 

[4FordFamily]

This spells disease to me. Could be ich or velvet. I had a strain of velvet that showed no outward symptoms on any fish for months, only attacking the gills out of sight. Horrible strain, anhialated my fowler inhabitants except my wrasses which are not very susceptible to parasites

 

[D maul]

Velvet can wipe out a tank if any fish are left check to see if they have it.

 

[Jnharris22]

The tank is very young.
that within itself can be an issue.
0 nitrates??
Stuff will be coming up so slow it down a little

I've been maintaining nitrate levels of about 2 - 3ppm but I got a 0 read after my water change so it's not completely zeroed out on nitrates and it never will be. I was just giving the most recent stats on my tank.

 

[Jnharris22]

Velvet can wipe out a tank if any fish are left check to see if they have it.

You are the third person to say this but how do I check? Everyone is talking about what it could be and I appreciate the ideas but how do I actually diagnose?

 

[twilliard]

I've been maintaining nitrate levels of about 2 - 3ppm but I got a 0 read after my water change so it's not completely zeroed out on nitrates and it never will be. I was just giving the most recent stats on my tank.

2-3 is perfect thanks for the info!

 

[D maul]

You are the third person to say this but how do I check? Everyone is talking about what it could be and I appreciate the ideas but how do I actually diagnose?

do you have any fish still alive? If so check the fish for golden dust on them that's what I had and I was too late to help them because I didn't know what they had

 

[madtownguy]

Diagnosing the problem isn't easy even for a professional. I'm sure by now you would have noticed ich, I think your tank is along far enough with that amount of live rock that it is established personally. For the small cost I would definitely start with a UV light on outflow for awhile. You could quarantine the fish, but if it's not disease in the tank it will probably just get them once they come back.

 

[Jnharris22]

Here are some pics, they aren't the best but I can't see any discoloration, bumps, weird or infected looking gills, etc

What do I do next to determine if it's a parasite or infection?

This spells disease to me. Could be ich or velvet. I had a strain of velvet that showed no outward symptoms on any fish for months, only attacking the gills out of sight. Horrible strain, anhialated my fowler inhabitants except my wrasses which are not very susceptible to parasites

 

[Jnharris22]

Possibly internal infection, nitrofurazone is good for treating fish that are sick. If it's parasitic you need to treat for that also.
Prazi pro is good for internal worms and flukes.
The butterfly was already sick if he wasn't eating.

Are you saying to treat without further diagnosis or are you just saying to use nitrofurazone once I've pin pointed the issue?

 

[Jnharris22]

Could be mantis shrimp or large worm caught a ride in live rock, I had that happen once and was puzzled for about 4-5 fish deaths. Both tend to come out at night.

How did you find it and are there any natural predators to worms or mantis shrimp that won't wipe out everything else?

 

[madtownguy]

You still haven't found your blue tang? I can't imagine one of those hiding so well. And for that amount of time if it was dead in the tank ammonia would have to go up. Anyway you can get a decent overall photo of the tank?

 

[D maul]

Are any of the fish breathing faster than normal or not eating? The fish that died did they hide or scratch up against rocks? Just trying to tell you what I seen with my tank. When the white lights were off and the Blues were the only ones the velvet stuck out like a sore thumb.

 

[Jnharris22]

How's this?

You still haven't found your blue tang? I can't imagine one of those hiding so well. And for that amount of time if it was dead in the tank ammonia would have to go up. Anyway you can get a decent overall photo of the tank?

Yes I still can't find the guy, I'm going crazy trying to figure out where the blue tang is. I haven't been able to see him for going on three days I'll check my ammonia again now...