There are pros and cons to every filtration. I see everyone is obsessed with media capacity. Looking at jaws7777 sump above, I can easily fit all that media in my external filters, though I don't use this type of media.
Have you asked yourself why a sump may perform generally better than the average canister filter setup, apart from some already stated facts. Its the increase in water volume capacity rather than the amount of media. Adding 70G of water to a 300G tank for example increases the water volume by 23%, and also the surface area for oxygen and bacterial colony. And generally people that need sumps also have quite the bioload to deal with because they tend to cram as many fish as they feasibly can in those tanks. If one constantly runs out of space in their tanks, every extra bit could be crucial long term.
I know a fishkeeper that is around on forums. His clown loaches are 23 years old now. Trials and errors, he's moved on backwards, to undergravel filters in his clown loach tank, to prevent failure, 23 years success, so my question is....
....When keeping these uber expensive fish with a sump running of one pump, what do you do for redundancy? What happens if you're not around and the pump stops? With multiple filters its very unlikely they all stop working, and if one filter biologically underperforms for one or another reason, the rest will pick up the bioload. And then again, you've got multiple points of failure with sumps, many connections, relying on two glass tanks to not crack or leak. I've had my shares of tank leaks so if its a sump, I'd go with poly and seamless.
The most I do care about is eliminate failure. Keep fish long enough and you'll know what I mean...though some people get lucky...
Looks it was underfiltered in the first place, even with the lone eheim super filter so its no surprise a sump did better.
Care to show your media amount you keep in the sump?
