Puzzled!

[gmdelaney]

Rank amateur looking for help. I started up a 50 gallon using ~70# of dry (dead) rock. Purchased one live rock from local fish store and added it along with a shrimp to the tank. I let the tank cycle for 6 weeks. At that time the ammonia, nitrite, and nitrate levels were all 0. pH = 8.3, SG = 1.023. Introduced snails. After 2 weeks, all snails alive and seemingly thriving. Introduced 3 green chromis. After 2 weeks all were doing just fine. I then introduced 2 clowns and 1 Coral Beauty dwarf angel. By day 2, all were eating and seemed to be OK. Day 3, one clown disappeared. Day 4, found the other clown dead. Day 7, found angel dead. All original snails and chromis doing just fine. Since then, I have introduced other fish and just as the clowns and angel, all seemed to be doing just fine. Actively swimming and eating. All have died or disappeared within 3-7 days. Did weekly 10% water changes during this period and tested once to twice a week. Never had any trace of ammonia, nitrite, or nitrate. pH always 8.2 - 8.3, SG 1.022 to 1.024. What really puzzles me is the fact that the original green chromis are all still doing just fine as well as all of the snails. The snails even laid eggs. Any/all suggestions welcome. Thanks in advance.

 

[Paulm87]

Seems strange that some things are thriving and others are dieing off. Sounds like your tank hasn't finished cycling or cycled at all. You will definitely be getting some ammonia from the waste and die off from the rock. Are you doing the tests correctly? If you are then something is wrong with your test kit and I'd buy another one. It will take a long time to seed all of that dry rock from just one piece of live rock. Have you added any chemicals to tank at all?

 

[gmdelaney]

Thanks for the reply. I think that the tank did cycle. Tests at the end of one week did show levels of both ammonia and at the end of two weeks both ammonia and nitrite (no nitrate). The test values were also confirmed at a local fish store. The only value that varied from mine was the SG which was 1.024 by their reading (at that time my test yielded 1.022). I didn't test again until 6 weeks at which time both my and the fish store detected no ammonia, nitrite or nitrate. Each time a fish disappeared/died, I tested and never detected any ammonia or nitrite. The rock I used was given to me by a neighbour who did salt water years ago. It had been stored dry in his garage for ~15 years so I doubt there was anything to die off other than perhaps the one "live" rock from the fish store. Prior to placing the dry rock into the tank it was divided between 2 - 55 gallon plastic garbage cans and soaked for about 5 days in tap water which was cnanged twice daily. The rock was then combined into one 55 gallon can and soaked for 24 hours in saltwater mix to equilibrate. I thought that since I observed a spike in both ammonia and nitrite that the tank had cycled. Is it possible that it didn't? I think that I am running the tests correctly. My test levels for ammonia and nitrite seemed to be identical to the fish store's values. All test reagents are within dating period. I had a minor in chemistry in college albeit a half century ago. Since at my age I sometimes not real sure of my own name so I suppose it is entirely possible that I'm messing the tests up some now. Any additional thoughts? Again, thanks.

 

[gmdelaney]

Have you added any chemicals to tank at all?

Sorry, I forgot to reply to this part. The only chemical added was IO"S Marine Conditioner which I added to both the make up water (to replace water lost due to evaporation) and the salt water used for the weekly water changes. Could that be a problem?

 

[blert]

Sounds to me like you are rushing things a bit by adding too many fish at once. One, possibly two, fish at a time and wait a month before you add another. Such a young tank is nowhere near established enough to handle large bioload changes. When adding fish also consider aggression levels: shy fish added first, most aggressive added last.

 

[gmdelaney]

Thanks, Blert. I'll give that a go. I am going to be switching tanks for the salt water to a 40 gallon breeder and a 20 gallon long. I don't feel that the 50 show has enough surface area to maintain dissolved O2 levels for salt water. I will convert the 50 to fresh water along with lots of aeration.
A couple of other questions. If I transfer the rock presently in the 50 to the new 40 gallon, should I expect a lot of die off of what bacterial levels that might be in the rock? Also, why do the chromis survive while newly introduced fish croak? Again, thanks for your help.

 

[Paulm87]

It could possibly be the chromis, I've never had them but I've heard they are quite aggressive. So perhaps they have been stressing the new fish.

 

[blert]

Thanks, Blert. I'll give that a go. I am going to be switching tanks for the salt water to a 40 gallon breeder and a 20 gallon long. I don't feel that the 50 show has enough surface area to maintain dissolved O2 levels for salt water. I will convert the 50 to fresh water along with lots of aeration.
A couple of other questions. If I transfer the rock presently in the 50 to the new 40 gallon, should I expect a lot of die off of what bacterial levels that might be in the rock? Also, why do the chromis survive while newly introduced fish croak? Again, thanks for your help.

Do it fast and keep it wet and it should be fine.

It could possibly be the chromis, I've never had them but I've heard they are quite aggressive. So perhaps they have been stressing the new fish.

Possibly, never had Chromis myself either. You might want to research this.

A good way to introduce new fish and keep aggression down is to use a breeder box type thing. After acclimation, put the new fish into a breeder box floating in the tank. Leave them in there for an hour, or thereabouts, so the old fish can see and get used to them without being able to chase or make contact. Just a thought, this worked well for me in the past.

 

[gmdelaney]

Thanks Paul & Blert. All the research I did prior to purchasing the Chromis indicated that they were a peaceful species. Then again, Mark Anthony insisted that Brutus was "an honourable man", albeit tongue in cheek. I have never seen them do any fin nipping however they do sometimes chase other fish, especially at feeding time. Perhaps the stress of acclimation combined with the chasing stressed the newly added fish to the point of no return. I like the idea of the breeder box, Blert. I will definitely get one. Again, thanks all.