[glampka]

As previously suggested, dump both the cramic rings & the balls. You might also want to consider blocking off the mid & lower intakes so that all the water goes over the top intake. Definitely consider upgrading to a MJ 900 or 1200.
Octopus are escape artists. You may end up finding it in the back compartments alot. Would be big trouble if he finds his way into the last compartment & gets under that false bottom of the other compartments.