I would filter it at the intake otherwise you could get bugs taking up residence in the tubing. Make a filter box, (or mod a birdnesting box maybe) and raise it a tad off the ground. Put the filter in the bottom panel so its protected from rain and cover the opening with 1/8" hardware cloth to deter rodents from nibbling their way in.
I`m sure you could have managed the 20ft but 15ft should be enough. I planted 165ft of tube 4ft deep using nowt but a spade
I`m sure you could have managed the 20ft but 15ft should be enough. I planted 165ft of tube 4ft deep using nowt but a spade