I may have missed somthing in reading these posts, but have we any definative answers about using wood chips/celulose in the purification of our Bio ? ie which types of wood are best, how are the used, and how long to expect them to last.

Wouldn't there be a problem with BD leaching harmful contaminants like sap and resin out of the wood chips and into the BD?

I think that if you are using kiln dried hardwood, the sap and resin issue is pretty much nonexistent.

I just made a couple of bags of poplar shavings that I intend to use next week. I have used red oak. maple and lytus with good results. I have no idea how the poplar is going to work.

I take the spent shavings and press them down into a paper sack to make a nice fire starter for the fireplace. One sack burns for about 15 - 20 minutes. Plenty of energy to start a nice fire.

Looks like there are NO DEFINATIVE ANSWERS out there. Makes you wonder

I think the jury is still out on this one Stumpy. Once my new pump is up and running I'll be doing some more testing.