Doing an approximately 6-800 gallon pond with 55 gallon drum filter. Filter will be fed from bottom homemade style and located at ground level about 6' away from the pond, overflow will be routed to waterfall at some point. Nothing too elaborate, will be well stocked with native plants and some minners, etc. Can someone assist with pump size ? I've seen the calculators but see varying opinions and assuming hose to drum inlet at a few inches above ground level there's little head calculation, guess I'm being lazy but like to research before "diving in" to my pond ! Thanks.