Doing a job that is having an underground aquarium installed in the downstairs walkout basement. The home has a 400a service using the 2 mains to feed 2 - 200 amp panels. I've added a 100a sub-panel from one of the 200a. I was going to add another probably 60a panel off the 100a to mount outside where the pumps will be. I believe its ok to run a sub-panel off another sub-panel.
I ran 1-1/4" PVC underground where the tank will be and stubbed it up on the inside wall near the 100a and outside where the 60a will be mounted. Later I can can pull in 6/3 NM w/grd from the 100a sub-panel to the 60a. Half the run would be in the PVC and half in the inside wall and ceiling. Wouldn't make sense to have to run the PVC all the way to the 100a feeder panel just to run THHN. I believe they use THHN on the inside of NM wire now anyway.
Also, just as a pool doesn't use a GFI, for the pump (only the light) I shouldn't need a GFI breaker for the aquarium pumps.
Anything wrong with all this?
