hmm if you wan to remove debris without water changes, and if you have a sump, you could try this method.
Attach the output of the gravel vac to the mechanical filter of the sump, like a filter pad. Vac the gravel. The debris would be siphon into the filter pad and at the end of the cleaning, replace filter pads.
Attach the output of the gravel vac to the mechanical filter of the sump, like a filter pad. Vac the gravel. The debris would be siphon into the filter pad and at the end of the cleaning, replace filter pads.