Would the removal (for aesthetic purposes) of several large pieces of lava rock significantly afffect the biological filtration in an octopus tank?

Michael O'Shea

not too much, but it will a bit, so maybe remove a bit a week or something????

As with anything biological, it depends on a couple factors. Take a large chunk of liverock out of a mini reef (<5 gallons) and you've tragically upset the biochemistry of the tank. Remove a small chunk from a 100 gallon aquarium and it'll hardly be missed.

Remove the rock and watch your ammonia (well, the tank's ammonia.. :P ) for a day and see if anything falls out of balance.

Cheers, Jimbo