What More Effective A Sponge Filter Or Undergravel

[simonas]

asthe above says really which is the most effective, just wondering for my lower staocked smaller tanks?

 

[bagu]

hmmmm

i have both, and i must say spong, due to the fact you can add carbon/floss etc

although in the cycling stages UGF was alot better! but is a hassle to clean