hooded fairy wrasse dying?

[gmann]

Came home today, and noticed my hooded fairy wrasse was lying on the sand bed looking lifeless. I proceeded to feed the fish thinking he would come up, but no go. An hour later i used a turkey baster n pushed some water his way to see if he was dead or alive, (he would not budge from that spot thank god).

Question is, he was swimming n eating actively yesterday. only changes that happened to my take within the last 3 weeks are:

1.using a subpar powerhead for the last 3 weeks while waiting on my gyre.
2. 20 gallon water change yesterday.

i checked parameters last night and they seemed fine, but i'll check again later.i mysteriously lost my suburst anthias last month, but chalked it up to randomness. if i lose this guy, i dont know what to do.

any idea what is going on?

thanks in advance