Ive switched over to the dual sponge filters in most of my tanks. Even in tanks with an already established filter, I like to throw one in cause having an extra seeded sponge filter is always nice. I actually got rid of my HOB
because it would clog and overflow within days even with minimal feeding. Sponge filters do a great job and are so easy to clean, I really don't know why they arent the first option.
The only possible downsides I can see are that supplementing with chemical filtration (purigen, carbon, or just needing crushed coral to raise kH
) isn't possible with a sponge filter the way it is with HOBS.
Also HOBS can tend to polish the water better if you use very fine pads (I'd use polyfill)
Otherwise, sponges all the way!