ive been using a combination of bio balls and scrubbies in sumps and it has been fine, but recently i came upon a ton of bio balls for free. i can fit alot more bio balls than scrubbies so im wondering if it would be better to use the bio balls because there are so much more of them. if someone knows the exact surface area for each that would help too cuz i could calculate it. i saw a thread about this before but cant find it now
