Country joe
Fishaholic
I've noticed on the Internet looking at aquarium sites, when changing your filter some say it's best to leave the two running side by side in the tank, I will be soon taking out the internal filter and replacing with a external, I don't wish to run them together, but by replacing the filter sponges on to the external, is this a better method, and would it be also beneficial to add Goop live bacteria to the external filter.