Graphite electrode destroyed in electrolysis

[Samson4]

I built a Hoffman apparatus with graphite electrodes. I hooked it up to a make shift power supply from an xbox powerblock. It was filled with battery acid for the electrolyte. Now, the graphite electrode is 99% graphite rod.

For some reason the graphite electrode on the negative(black) connection turns to powder. It stops producing gas; upon inspection, I find black mush floating in the electrolyte. Can anyone shed some light on the reason why? I'm tired of redoing this. It also happened with corrugated graphite ribbon electrodes.

 

[DrStupid]

For some reason the graphite electrode on the negative(black) connection turns to powder. It stops producing gas; upon inspection, I find black mush floating in the electrolyte. Can anyone shed some light on the reason why?

The graphite electrode turns to powder because it is made of powder. Use carbon fibers instead.