Koi Pond bottom drains

Pond Bottom Drains

Pond bottom drains are gaining popularity in the pond industry as homeowners and pond contractors discover their benefits.  Adding a pond bottom drain will reduce maintenance, add aeration while balancing the water column, and remove fish poop (some builders refer to a bottom drain as a koi toilet for this reason).

It’s very important to size your bottom drain filter system correctly.  Otherwise it will not function properly and become useless.  If you have any questions on your bottom drain setup please contact us.

HydroSafe Fish Safe DrainView Product Page

pond bottom drain russell

The HydroSafe koi pond bottom drain is fish safe and won’t suck fish into your pond plumbing.   Baby goldfish and koi are safe as well.  Features two 2″ outlet ports (use both, or one) that can connect to 2″, 3″, and 4″ gravity fed bottom drains.  Recommended to be used with HydroSieve pre-filter.

Retails for $59.99


2 Inch EasyPro Bottom DrainsView Product Page

bd1 koi pond bottom drain

2″ Koi pond bottom drains that includes fittings and valve, bulkhead fitting, and bottom drain. Doesn’t come with PVC pipe. These bottom drains are a perfect match for the EasyPro small pro pond skimmers.  Optional model with air diffuser attached.

Retails from $179.99 to $199.99.


3 Inch EasyPro Bottom DrainsView Product Page

3" EasyPro bottom drains

3″ Koi pond bottom drains that includes fittings and valve, bulkhead fitting, and bottom drain. Doesn’t come with PVC pipe. These bottom drains are a perfect match for the EasyPro medium pro pond skimmers.  Optional models with air diffuser attached.

Retails from $96.79 to $285.39.


4 Inch EasyPro Bottom DrainsView Product Page

bd4 bottom drain pond

This in-demand 4″ pond liner bottom drain has been remodeled, and available without (EBD4) or with an air diffuser (EBD4A).  Featuring 16 stainless steel screws that attach the base to the pond liner ring for a solid water seal.  No need for a rubber coupling with the welded and threaded FPT inlet.  Superior strength with its roto-molded housing.  Has a threaded center stand pipe to attach the base to the dome lid.

Retails from $169.99 to $219.99.


Atlantic Bottom DrainView Product Page

atlantic bottom drain kit for skimmers

Atlantic koi pond bottom drain setup for their Pro-Series pond skimmers.  Provides an easy way to pull debris and sludge into the skimmer.  Does not work with the PS3000 Atlantic model.   May work on other brands, but check dimensions before ordering.

Retails for $102.84.


Rhino Retro Bottom DrainView Product Page

retrofit bottom drains

Aquadyne retrofit bottom drains are durable and offer a quality product for people who want to install a drain on top of their liner, or retrofitting a existing pond.  Over the liner bottom drains also allow you to move the drain around if needed.  Such as in the winter you can move it to a shallower area to allow the deeper water to remain warmer.  Comes in 2″ or 3″ models with the option for adding aeration.

Retails from $96.90 to $174.00.


Rhino Heavy-Duty 4 Inch Bottom DrainView Product Page

heavy duty bottom drain rhino

These are one of the strongest 4″ pond bottom drains on the market without jumping up in cost to $1100.00 or more for stainless steel models.  Built out of Schedule 80 PVC and thermally welded by hand and not speed welded.  With thick flanges that will not distort, crack, or flex.  Available with or without an air diffuser.

Retails from $349.99 to $379.99.


Frequently Asked Questions

The reason you should add a pond bottom drain is to minimize maintenance.  Drains will help create a circulation patter that will help remove organics and boost beneficial bacteria activity.  The added aeration and bacteria will be better able to break down any dust, pollens, pine needles, or leaves that settle into the pond bottom.

Most builders today will usually install a 4″ bottom drain on their koi ponds.

That depends on your pond design.  If you provide us with more information we can better assist you.

It really depends on the flow rates you’re going for in your filter system, but in general a 10′ diameter pond will need a 4″ drain, and 8′ diameter and under can use a 3″ or possibly a 2″.

One drain per 5000-6000 gallons of pond water. If there are any odd shaped parts of the pond you may want to add a second drain in that area.

The drain should be placed in the deepest part of your pond.

We also recommend using a settling chamber (read more at WGI website here).  Note, that you should try and keep pipe work into the settling chamber as short as possible to avoid solids settling in the pipe itself.

The air bubbles work to pull water into the bottom drain.   This happens as the air bubble rise through the water column to the surface and water is pulled behind the bubbles.  Additional aeration is always a welcome addition as well.  Pond aeration promotes a healthy ecosystem and breaks down organic waste better. Note that the drains come with just the diffuser.  You will need an air pump and equipment sold separately.

Go back to the main pond plumbing page.