by Chris Thomas January 08, 2024 5 min read
When building a koi pond, hobbyists must choose whether to use gravity fed system with a bottom drain, or a pump fed system. The cheapest way to build a pond is to build it right the first time, so making the right decisions at the planning stage can save you money. By choosing the right system, and matching your pond equipment to compatible components, you can improve your enjoyment of the hobby.
In this post we will explain 11 examples of why we think you should use a bottom drain in your pond build.
What is a Bottom Drain?
A bottom drain is a sump that is fitted at the lowest part of the pond. Generally two types of drain are available
On the left, the standard bottom drain. Black in colour, they are injection moulded and usually have a 110mm socket. On the right, the aerated bottom drain. Fabricated from PVC pipe, PVC sheet, and PVC fittings, they feature an air diffuse for a dome.
The working principles of both drains are essentially the same. Located at the bottom of the pond, they feed water directly to the filter via a 100mm/4” pipe. Bottom drains can be used on ponds lined with fibreglass, or pond liner when used with a clamping ring. People often worry about cutting a liner when using a bottom drain, but with the correct sealant and a liner clamp, you shouldn’t have any problems sealing the drain and liner.
The above schematics show the difference between a Gravity fed (top) and a pump fed (bottom) installation of the Evolution Aqua Nexus 220+/Nexus 320+ filter system. In the Gravity system, a bottom drain is used with 110mm/4" pipe to deliver water to the filter, and then a pump circulates the water back to the pond via a UV.
For aerated drains, the 1” pipe feeds the air from an air pump to the sump, and via the stem to the diffuser.
Detail shot of the inside of our Aerated Bottom Drain. The air is supplied to the dome via a 1" pipe, that feeds direct in to the stem for the drain lid/diffuser, minimising the risk of entrapment by additional air lines in the sump/drain line.
At Kitsu Koi, all our ponds are gravity fed with a bottom drain.
Here are our 11 reasons why you should use a bottom drain in your koi pond
Hopefully you are now pro-bottom drain and can see the benefits to your pond, fish, and koi hobby. We have seen all the excuses for people not using a bottom drain for a koi pond, and not one of them can’t be overcome, leading to most if not all of the above benefits. We simply won’t build a pond without one - in our premises or for customers.
If you’re in need of a bottom drain, and all the rest of the components to build a quality koi pond, then start your journey with Kitsu Koi. Below you will find links to our popular bottom drains, pipework, and valves needed to start your build. Then you will need to choose your filter - we recommend a visit if you can to see our filters in action, or call for more information.
|Aerated Bottom Drain
|Grey PVC Pressure Pipe
|PVC Pressure 90 Degree Elbow
|Ever-Weld p-194 Solvent Cement
Chris has been keeping koi for over 25 years, and dealing in koi for 15 years. Travelling to Japan to select new stocks is the favourite aspect of the business, closely followed by being on the tools pond building.
Comments will be approved before showing up.