I've got three small CNC mills I use primarily for high speed (24K RPM)
milling of aluminum. I use flood coolant with distilled water and and about
5-6% SC520. Each has its own smallish coolant tank and it works ok, but I
am constantly adding water, and to lesser degree SC520. I've been playing
with the idea of using the on machine tank as a sort of chip filter to
reduce coolant nozzle plugging from fines, and to make coolant maintenance a
little easier.

I'd put a bulkhead connector in the side of the on machine coolant tank, and
let it drain into a much larger tank. I'd also add a baffle to get coolant
draining from the machine pan to flow into the on-machine tank at the
opposite end. Then move all the coolant pumps from the on machine tank to
the bigger tank. Maybe add a simple hemispherical filter screen to the
inside of the bulkheads.

Is it a good idea?

Am I forgetting something?