Sumps?

[Le Sorcier]

Been looking at new tanks and a couple come with sumps underneath?
 
I've no idea what they really are used for?  Are they instead of a filter in the tank, or they they more for specific types of fish?
 
thanks 

 

[fluttermoth]

They're basically a big filter, yes

 

[Metka]

Having a sump basically allows you to have more fish stocked in your tank - the sump is effectively an extension of your main tank (in terms of its water volume).
 
This is the case for canister filters too, but most canister filters are 5-10L maximum. (so don't really count)
 
Sump's are known to be noisy though, as it's gravity that makes them work (so you're going to get splashes where the water overflows out of the main tank and lands in the sump below). Something to think about depending on where abouts in your home the tank will be held.
 
I'd personally love to have a sump tank, and it is something that I want in my dream fresh water tank

 

[Le Sorcier]

Ah thanks guys.
 
As sound is a major issue for me I guess an external filter will be better for my 180l tank?