Did Osmotic Shock Kill My Urchins?

[fishlette]

a few days ago i bought some sea water from my lfs. they finally have it in and its way easier than mixing it so i figured id get some. i made the stupid mistake of not testing the salinity of the water in my defence, their water has always tested 1.024 and i was in a hurry so i didnt test. anyway, after i had done a water change i did a test and it read 1.028 i tested the water from the shop and it tested 1.029. apparently, our sea waters salinity is higher due to the drought i dont know if its possible but im no...person who would know that

i slowly bought it back down over the next few hours and from what i could see, everyone was doing ok. the corals seemed completely unaffected which made me very happy indeed.

yesterday i noticed i hadnt seen the collector and sector urchins. i found both of them today spikeless and dead (obviously lol)

could it have been the rise in salinity and then the drop again??? ive certainly learnt my lesson and will check ALL water in future

 

[Danno]

The rapid salinity change could have caused the problem but no one will ever know what really happened as long as your basic water parimeters are all inline. Hope very thing goes better next time.

 

[fishlette]

The rapid salinity change could have caused the problem but no one will ever know what really happened as long as your basic water parimeters are all inline. Hope very thing goes better next time.

yes my water parimeters are very good. i bought a new sector urchin yesterday cause the urchins were my hubbys and he was a bit upset lol

 

[SkiFletch]

Urchins are pretty sensetive inverts. It's possible that either the hyper salinity (too high) event itself killed them, or the rapid drop. Tough to say which one it was...