Stuart, leave the UGF in. Just don't use it. Stop the flow,
Vacuum every inch of gravel till is very clean. Clean under
the plate if possible. I used a small hose, alternitly
drawing and blowing water. I also shortened the lift tubes
just the hide them.  The shoplights are OK, but I once read
on the net they eat lights. Mine in the garage (6 pair) go
thru cheap lights in a year. Many people recommend replacing
the ballast with an electronic one.
Read all the archives on this list. These people know their
stuff. They have unknowinly rescued my tank and reduced
my frustration level. My plants grow now, they used to die
slowly.. Thanks APML contributers..Mike