Hi Adam,
Having 2 pumps would be nice, if one goes down, you at least have emergency flow. Basically would be better then having a backup pump in the closest just in case.
If you have split returns, you would run one return from each pump to each return right?
If it were me, I'd try to increase the size of the existing hole to accept a 1-1/2 inch bulkhead. I'm pretty sure it is not a good idea to starve these pumps, it could cause cavitation.
Takayan - We are in the same boat. I got a Marin 200 and a 80 Dragon 3 Speedy 80 Watt W/10V. I am looking for a sump to house them. Let me know what you end up doing?
Since I bought BK double cone 250, I need to replace my sump with a larger size.
I bought RD3 80W as well, so I have two choices how to use RD3. One is for in sump and other is external. If I want to use the RD3 in sump, do I need to put any PVC at the inlet side? Or just use it as it is?
Your input is very appreciate.