Hi, Pam,

Wow! That is an issue! Al is much better at these things than me but I'll try to help a little 'til he can chime in.

The fact that the guage is responding to the pump makes me think that it is not broken....however, that is certainly the most logical answer. It is also a cheap fix. If there is a pool store near you, you should be able to pick up a new guage (10-15$) and change it out yourself.

Most of them simply unscrew right behind or right below the guage. Wrap a couple of turns of teflon tape around the new threads and screw it in. You should be able to do this with no tools....hand snug is plenty of force.

If you accomplish this, try the backwash again and see what you get. Post back. Others will be along to help you find a solution.

Pam, you did confirm that the guage is moving backward, right?