salinity and fish mortality

[addicted2reefin]

ok, all my corals are doing beatiful, but most of the fish i add to my tank die. i have a 20L and so far the only fish i have succesfully kept are clowns. today i just came home to my brand new flame angel being eatin by my hermits. i keep my salinity around 1.026, but i checked it and it was closer to 1.027. i have a black percula in there that seems fine. and all my other params are in check, cept my ph which is around 8.0 i was wondering if the high salinity could be contributing to my fishes mortality rates.

 

[Gwynhidwy]

That isn't high enough to kill a healthy, unstressed fish. However, if when you get the fish they are coming from tanks with a much lower salinity, for instance many fish stores keep their salinity low, the rapid change could kill them. Are you quarantining?

 

[MatthewLaw]

just to eliminate the obvious, have you checked your basic levels of amonia, nitrite, nitrate?

 

[Conesus_Kid]

When was the last time your refractometer was calibrated? If your answer is "It came calibrated from the factory.", I'd double check it. I lost the first three fish I ever purchased b/c of a non-calibrated refractometer.

 

[snorvich]

Some great answers in the three above mine. When you get a new fish, you should quarantine but in any case you need to acclimate to any salinity difference in the transport water and your tank water. Measure using your CALIBRATED refractometer both tank water and bag water and slowly make them the same. The larger the difference, the longer the acclimation period.

 

[NuTom]

A Flame Angel should not have been added to a 20L.


20L is about what 5GL? Only thing you could get is a clown goby, shrimp, snails, crabs and thats about it.

 

[klasiksb]

I think he may have a 20 gallon long.

 

[addicted2reefin]

20 long, i think that was it, my bud keeps his salinity about 1.022. i dripp acclimated him. i bought him on tuesday and he died today( thursday) i dont use a refractometer, i use a hydrometer(deep six) im trying to get my hands on a refracttometer, i guess i shoulda spent the 60 on that instead, i would still have it. he just came in that day when i bought him, then the stress of my new tank, and all killed him im assuming

ammonia 0 nitrite 0 nitrates 20

 

[Elysia]

I have two wild fish that are in a 20 long and which (slowly) changes salinity to extremes. EXTREMES. Some fish can survive salinity over 1.030. I'm not saying all can. I'm not saying that it is good for them. And I am not saying that you should change the salinity quickly. But, if, over time, the salinity changes, some fish are hardier than one might think.

 

[MattL]

I think there is some more information that is needed -- a salinity of 1.026 is nowhere near high enough to kill a fish.

How old is the tank? What fish are/were in the tank and when were they added? What and how much are you feeding? What is your filtration system? What is your acclimation process? Where did the fish come from, and what is the salinity and pH of their water?

Matt

 

[snorvich]

1.0264 is the average salinity found in natural sea water (NSW); I try to keep my tanks there but they slip. Changes in salinity that are extreme can be problematical.

 

[JoelNB]

Are 1.020 or 1.030 extreme?

 

[MatthewLaw]

1.020 is not extreme for fish. i know a good amount of fish owners that keep their FOWLR tanks at around 1.018 (and no issues).

 

[snorvich]

Well, low salinity is probably not healthy for fish long term.

 

[Elysia]

It will also depend on the fish and the amount of time it takes to get to the "extreme" reading. When you have a fish that adapted over time to live in an environment of extremes, like those of tide pools, then those fish can survive the relatively slow changes of most individual's tanks. For example, I have two fish from tidal pools of the Atlantic. They are in a 20 long that isn't topped off as often as it should be. Then the other month I wasn't really thinking and I added more freshly made saltwater than I had removed. The result: their water read 1.066! But they are eating and healthy and I am bringing the salinity back down into normal range. I wouldn't have suspected that anything could have lived at reading!

 

[Laddy]

I agree, there is a complete disconnect with what LFS', wholesalers, and reef/saltwater fish keepers do.

The people selling the fish/corals are just trying to keep them alive until they sell them, and they have cost considerations to keep in mind.