Go and get a buddhist chanting CD, do a voice over saying photo photo photo over the hymms and then post it here...
I'm sure Desi will post the photos immediately after hearing it...
I have a feeling that the Seachem MG is not concentrated enough and thus is unable to raise your MG levels sufficiently. You may want to try other MG additives instead.
It can cover 4x2x2 but there will be some light fall off at the edges of the tank. Some people in RC are using 2x160W for a 4x2x2 tank though but if you are just keeping LPS and softies, then a 180W would be more than sufficient.