Remember hydraulics is just like electricity when it come to flow. If you hook your filters up is series like you want to, applied pressure and GPH must drop and if hooked up in parallel (separate) applied pressure and GPH stays the same. Also just like the old Christmas lights that were in series, if one bulb fails all lose power, so likewise if one filter fails in series, flow will stop in both doubling your chances of total shutdown and loss of all redundancy, whereas in a parallel circuit one circuit failure dose not affect power to the rest of the components and so likewise your filters in parallel will not affect one another and have redundancy. Parallel is the only way to go.