How to Install Gravity-Flow Filters for a Koi Pond

A gravity-flow filter is used to keep a koi pond free of algae and to make a biologically stable environment. This keeps the koi healthy and the water crystal clear. Gravity pushes the water into the pump through a drain where it is cleaned and returned to the koi pond.

Difficulty: Moderately Easy

Instructions

1. Install a drain in the bottom of the koi pond. Connect the drain to the gravity-flow filter via pipework. Use a slide valve to separate the gravity-flow filter from the pond when needed.

2. Dig a hole in the ground alongside the koi pond. The hole should be deep enough that the top of the gravity-flow filter is 1/2 an inch above the water. Make sure there is at least an inch clearance on all sides of the filter as it won't function properly if there is pressure on the unit.

3. Utilize a pump to return clean water to the pond. Make sure that the size of the pump is compatible with the gravity-flow filter. The pump should be positioned in a separate chamber than that of the filter.

4. Adjust the flotation system to stop the water from going so low that the high speed pump can't return it. Loosen the bolts on the pump and push the float to the position you desire. Tighten the bolts again.

5. Connect the waste outlet to the gravity-flow filter. It is connected with a PVC pipe that fits around the slide valve. Glue the PVC pipe to the slide valve.

[probert]

on 8/9/2008 in hi i have made a koi pond out of 4x4 posts it is above ground at 12x8x4 i what to install a 4 bay clover leaf with a portable bottom drain the filter will be about 1 foot from the top of the pond how can i get the water flowing back into the pond will i need a pump in the last chamber to pump it back into the pond thanks