-I'd also say the maintenance is easier with a canister, I set up the media so that I only need to open them once a year or longer - they just keep working without a hassle.
-Less chance of leakage as there is no need to drill the tank and it is a sealed unit. Some of the ways people set up their sumps can cause a disaster.
-Looks nice, sumps are somewhat unsightly.
These three got me enough to comment in reply :icon_redf
Cleaning;
Maintenance is easier??? but you only open the can once a year?
The sumps I run that have floss panels in them I can change the panels out weekly in less than a minute without even shutting off the pump.
Changing / rinsing media = gunk removed not running my water through it, seems like a better idea.
(this is the big one for me)
Leaks;
Motor head o-ring, primer o-rings, inlet/outlet o-rings, 2 line valve disconnect o-rings, inline heaters, CO2 reactors seems like plenty of places to leak. :icon_roll
My sumps have 2 drain lines that are hard clamped, the return line is clamped, reactor, heater yada yada are contained within the sump.
Same chance of my sump leaking as there is my tank seams will fail.
Admiring my tank not the plumbing.
I don't think I have ever considered saying oooohhhh what a pretty canister! Eheim pro II 2028 (x3), Pro3e 2078 & a classic here but all are hidden behind cabinet doors.
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Power consumption for the return pumps can be compared with most cans using about 30watts the can is cheaper to run without searching for a balanced answer for the return from a sump. I only have reef keeper turn over (10x) on one system but for the power use to balance with the cost of 2 Eheim 2028's will require running it for about 8 years. :icon_eek: