Clam not looking good

[Tajjo]

I have had this clam for over a year and has looked great but lately it isn't opening as it uses to. Another died 2 weeks ago I have no idea why. Any ideas?

[sland]

Post up your parms..maybe something is off? Any spikes in levels...bulb changes, light schedule change...water flow...there is a ton of variables....when you mean not opening like it used to, what do you mean by that?