Have you considered having housing 2 pumps inside the volcano? You could have one pump that draws from the outside of the volcano, just run a tube under the black acrylic and then have the output running to a barb on the inside of the res allowing that to flow to the outside. kinda like having 2 barbs thread to thread facing opposite.

Then have the return line from the loop flow into the inside of the volcano with the DB1 sitting inside with an open inlet and you could possibly use a ball valve on the inlet to help control the flow of water out of the volcano. This will allow 1 pump to maintain loop pressure while the other provides the water gushing.

maybe make a sealed box for the main pump (DDC aren't submergable iirc) since I doubt that the DB1 could push enough water up fighting against a DDC, tho I could be wrong.


Its 345 am, I hope I kinda made sense.