The nexus 220 is suitable for ponds up to 4 000 gallons while for larger ponds the nexus 320 can be installed on ponds up to 7 500 gallons.
Gravity fed pond filtration system.
The pump which can be in or out of the water forces water into the top of the gravity filter and the water is filtered through lava rocks or bio balls and then through a filter mat.
Constructing a gravity fed bottom drain pond filtration system the theory is fairly simple really you basically have two areas of water the pond and the filter whose water levels need be parallel.
All nexus filtration systems can be installed on pump fed or gravity fed setups depending on your pond configuration.
Some can be gravity fed most are pump fed.
You then have a pipe from the ponds bottom drain sloping downwards underneath the filter then up and into the top of the filter.
Non pressured filters have a non airtight lid allowing atmospheric pressure to enter the top area of the filter.
From oase this filter is a fantastic product that offers both mechanical and biological filtration through the gravity fed single chamber process.
Gravity then forces the water back into the pond either directly or through a waterfalls.
These filters sit above the water.
The high surface area foam media works to remove debris effectively and the biological screens work to balance out bacteria and promote good bacteria growth decreasing waste and harmful chemicals within the pond.