Bottom drain, do I really need one.

Hi its lee from the Japanese Water Gardens, in this video I am talking about bottom drains.

What are they?

What's the advantages of using one?

Can they be used with a pond liner?

Are they essential, or can you get away without one?

Keep watching and lets see if I can answer a few questions about bottom drains.




A bottom drain for a pond is manufactured unit that sits on the bottom of the pond at the deepest point and transports water through a pipe into a filtration system.

The water level in the filter is the same as the pond level.

After the water has been filtered it is pumped back to the pond.

We refer to this arrangement as gravity fed pump return filtration.

This is a highly efficient setup and there are many good reasons why this works better than alternative arrangements.



Water is being taken straight off the very bottom and this is where the dirt would normally accumulate so there is no sediment layer forming.

The flow of water through the drain and pipework is gentle and does not fragment the delicate solids produced by the fish. This means that the filter is removing large solids, not fines. The large solids are easy for the filter to settle out or sift out.

With a bottom drain system all of the plumbing is hidden and you don't have electricity cables running into the pond. This means its looks more professional and you don't have pipes and cables holding sediment or hampering you vacuuming the bottom off.

Bottom drains are energy efficient too. You can use a low wattage circulating pump to push the water back into the pond. There is no lifting of water and that means less energy is required to establish the flow.

Pumps tend to last longer and require little maintenance as the water passing through them is clean and not contaminated with solids.



If you have watched my videos before you will have heard me say that I think that fitting a bottom drain is perhaps the single biggest step in the right direction that you take when building your pond.

So why don't all ponds get fitted with a bottom drain?

Bottom drains and the required pipework are normally installed when the pond is constructed. Retro fitting a drain is sometimes possible but it can be a tricky job depending on the circumstances.

Sometimes people are reluctant to install a drain because they are worried about sealing it onto the liner.

But this is a very simple thing to do and I can tell you in 25 years of working with ponds I have never known anyone actually have a problem.

The drain has a flange that is covered with siclone and clamped down onto the pond liner with screws to create a watertight seal.

Installing a bottom drain does take some extra effort at the construction stage and I will not be so bold as to say they are essential to the success of every pond but make no mistake there are some huge benefits.

Thanks for taking the time to watch this video, if you want to see more help support the channel subscribe give the video a thumbs up and post any questions in the comments below.

Its bye for now from Lee at the Japanese Water Gardens.

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