I was wondering if some one could give me some advice on the requirements to fit retro bottom drains. I have a 1400g pond (timber and liner contstruction) that sits about 8-10" in below ground level then raises up to 30" above ground level. at the moment i have an optimax sat on the pond floor pumping up to a biotec 10 then gravity back to the pond. but ive just upgraded to an easy pod and would like to get it gravity fed then pumped back in (i want to sit the pod as low as i can to the ground) thus meaning having to fit a retro bottom drain and then mount the optimax externally.
my question is will the water have enough pressure acting downwards to force the water up over the wall and the down a bit followed by another raise up into the filter? i have included some pics of my pond so you can see what i’m talking about. i’d like to sit the pod at ground level where the current filter is.