Think I have some bad news.
Last time I saw the Cleaner was Friday evening - He was chowing down on Mysis. He wasn't being chased or hassled by any of the tank mates. Zero signs of disease or lethargy.
Its now Tuesday afternoon and I haven't seen him since...
Parameters are fine:
Ammonia - 0
Nitrite - 0
Nitrate - 20
pH - 8.2
I'm going to monitor the ammonia over the next few days and see if there's a spike. If so - my thoughts may be confirmed. I guess I should have heeded the advice I have seen about these not lasting very long...