you will have an mp10 in a 6 gallon tank? That will be some flow or turned down very low. I think you know but salinity is low and ammonia should be no existent. A water change might help. Is anything in the tank? Looked like some snails. Good luck with it will look neat when all done.
BTW, I briefly considered getting an MP10 for my 1.5 gallon tank I don't think having an MP10 in a 6 gallon is too crazy. I'm pretty sure that I've read a few posts with people having them in 5 and 10 gallon tanks on a different forum.