I'm running the AquaFX version of the BRS units - 2 singles with separate pumps
Got them from J&L
The 10" canisters can physically hold 8" of media, although I'd rather not
In my 110g total system I use 225ml GFO and 150ml Vertex Rox
When running, the GFO is 3-1/8" tall, and the Carbon is 2-1/2"
I'd see no issue running these on a system as large as 250g, although you'd need to stir the media frequently to avoid clumping (crack the valve open to allow full flow, then reset the flow)
Go ahead and use them
, or buy them from J&L
I prefer the singles for adjustment and changes
Single
Dual