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Personally, I would be more worried about figuring our WHY it died. As far as "chemicals" go...not realy anything to worry about. Dead and decaying animals can produe more NH3
in the water then your tank's biological filtration can process so the risk to additional livestock is still there. However, if you promptly removed the ray and have a good amount of biologial filtration in the tank you should be okay. Best practice would be to have plenty of prepared and aged SW
on hand to do a water change if needed. Test water parameters (NH3
) twice a day for a week to make sure all is well. Turn your thoughts toward the casue of the death as well.