So i have been thinking
I am designing a gravity system
Originally i wanted the pond to stick up 0.5m in order to accommodate the filtration at surface level, but the more i look at things the less practicle it seems .....
so i am considering a gravity system at ground level, but then i thought when i flush my mechanical filter how do i get rid of the water i am draining ????
then i thought if i dug a mini septic tank to the side and below this filter box do you think this is a viable way of draining the water????