More Than One Filter

[Rodders]

would you put it in series or parallel?

Series to me seems the best. They will have an external pump, so the canisters are only filters.

 

[Lateral Line]

Parallel. If you place them in series, you will need to stop both in order to clean either which is not the case with a parallel setup. Additionally, since the water now has to go through two filters instead of one, the dissolved Oxygen available to bacteria is lower in the second canister then it would be with a parallel setup - this will inhibit bacterial action.