Nishikoi 90 Degree bottom drains designed for use in all sizes of ponds. For details on using bottom drains see "Getting to the Bottom of Bottom Drains". Order by pipe size. 4" pipe Nishikoi 90 Degree bottom drains designed for use in all sizes of ponds. For details on using bottom drains see "Getting to the Bottom of Bottom Drains". Order by pipe size.

Skimmers and bottom drains work together to keep large koi pond crystal clear. As a general rule ponds above 5000 gallons need a drain and an additional drain for each 3000-5000 gallons. Your flow rate also effect how many drains you need.

The pipe work from the drain to the settlement chamber should not be too long. This is because although there is water flow through the pipe work, the heavier solids tend to settle out and can build up in the pipe work itself. Pipes should be as short as possible and avoid bends if possible. Adding an aeration pump with increase the efficacy.