Fish are stressed & dying within 24hrs

[YellowFinsReef]

I'm not sure what happened. The only thing that I changed was the salinity, which was at 1.029 and I brought it down to 1.025 by adding fresh RODI. I've done it in the past and never has it been this severe - meaning no death, no nothing. I've got dead clowns and filefish. The wrasse seems to be stressed but I can't tell because they're under the gravel. I've removed some fish when i saw this happening. The corals are also puffy looking. Any idea what this could be? This is a 46G.

 

[YellowFinsReef]

Should I just bring it back up?

 

[azreeftank]

Did you slowly bring the salt level down or added the RO water in one shot? If you did then there is your answer that’s a HUGE swing if it was done fast

 

[DeniseAndy]

Should not be drop in salinity. Fish can handle the drop much better than the rise. Temp? System details? How long have you had fish? Any signs of disease? Possible contaminant?

It is a huge swing, but should not cause instant death on clowns especially unless they are already sick.

 

[DeniseAndy]

For instance, if I have had a fish with illness, I have dropped to hypo in matter of minutes and never had fish die on me (at least not from the drop, and never within first 48 hours).

 

[azreeftank]

Should not be drop in salinity. Fish can handle the drop much better than the rise. Temp? System details? How long have you had fish? Any signs of disease? Possible contaminant?

Not necessarily it can definitely be the drop that did it if it was instant. It could also be the temp of the RO water going in and the drop in salinity. With that much water being added it could have been a drop the temp as well as the salinity instant.

 

[YellowFinsReef]

Everything is healthy and eating well. No diseases. They just dropped dead. The tank is a year old and all inhabitants are 3+months old.

 

[YellowFinsReef]

Not necessarily it can definitely be the drop that did it if it was instant. It could also be the temp of the RO water going in and the drop in salinity. With that much water being added it could have been a drop the temp as well as the salinity instant.

So how do I fix this?

 

[DeniseAndy]

What other fish do you have?

 

[YellowFinsReef]

What other fish do you have?

Just some wrasses which I'm not even sure how they are doing.

 

[azreeftank]

The damage is done leave the salt lever at 1.025 for sure don’t take it back up. How many days passed of you not adding fresh top off water that the level got that high?

 

[DeniseAndy]

I have had my salinity get high overnight in my picos and nanos in the past. Not quite to 1.030, but certainly to 1.028 and I drop them to 1.025 instantly with no issues. The water is correct temp and rodi. Never had a loss.

Something else is bothering them. The corals you said were mad? How? What corals?

 

[roberthu526]

I have dropped salinity from 1.025 to 1.012 in one water change with no effects on the fish many times. I am a strong believer of Hypo btw. So I doubt the drop in salinity caused the stress. It may be ammonia spike or PH swing that had caused the deaths.

 

[YellowFinsReef]

The damage is done leave the salt lever at 1.025 for sure don’t take it back up. How many days passed of you not adding fresh top off water that the level got that high?

I wasn't home for a week and came back to a tank that wasn't well taken care of. My usual salinity is 1.026.

 

[azreeftank]

Do you have for own RODI filter and maintain it or did you buy the water? When did you last change the filters and do you know what the TDS of the RO water is if you make your own water?

 

[DeniseAndy]

Did you notice flared gills on the dead fish? Gills extended.

 

[YellowFinsReef]

I have had my salinity get high overnight in my picos and nanos in the past. Not quite to 1.030, but certainly to 1.028 and I drop them to 1.025 instantly with no issues. The water is correct temp and rodi. Never had a loss.

Something else is bothering them. The corals you said were mad? How? What corals?

Gorgs and some lps, they're just swollen like they're gonna burst. I've never seen them like this before.

 

[YellowFinsReef]

Did you notice flared gills on the dead fish? Gills extended.

No, just rapid breathing and laying on side

 

[DeniseAndy]

How many gorgs and how large, also, what lps? I only ask, because those corals are not overly compatible depending on number and species and will cause issues to each other. Not the fish issue though.

 

[YellowFinsReef]

Do you have for own RODI filter and maintain it or did you buy the water? When did you last change the filters and do you know what the TDS of the RO water is if you make your own water?

Yes I make my own. Filters were changed a couple months ago. Still reads at 0 TDS.