I have a long haired cat and although she is too fat to get behind my tank stand where my sump is, I do have to regularly clean up hair and dust that makes its way back there. My sump is also partially covered, not so much to keep anything out, but to keep salt creep and splashing in. I think household cleaners and other aerosols are more important to keep out than pet hair. JMO. My cat spends hours staring at the tank from her favorite spot on the couch across from it, but has never made an attempt to disrupt it. I think she knows my domino damsel would give her a good fight if she moved too close to his teritory.
