Guppy help

[Jayson]

I have guppies (used to be 7 now down to 4) in a 10 gallon tank and they seem to be going down in the gravel and dying. Don't really know what I'm doing wrong. Everything as far as the water goes is perfect. Can't seem to figure this out??

 

[butterfly_koi]

Over crowded? Stressed out maybe?