dont forget to cap the pipes that will fill with air (drain lines). also post some pics once you seal er up.I have 3 pumps. All in the sump. #1 pump circulates from sump to display. #2 is a closed loop for display (so display tank water not mixing into sump). #3 is pumping water to the fish room filtration system (top of the 3 40G breeder).
I will turn off #1 and seal up the display tank. Only the powerheads will run. I will also run the air pump to it from outside the house.
The water in sump and 3 40G breeders will be contaminated. I will replace all water after the fumigation and use carbon. I will let the display tank isolated for couple more days before turning pump #1 on.
This is before... I hope I will post an after photo with all the fish still swimming around.
Then I have my old 65G which I will take out all 3 fish and keep them in the 300G. This is going to be fun: