Bottom drain help

[DrDave]

My ponds (for the past 43 years) have done fine without a bottom drain. Depending on how you plumb it, it is possible that your pump can empty your pond and then have the pump burn out.
With submersibles, you never hear the pump, it seldom burns out because it is water cooled, if it is off the bottom by 6" or more, you never have to worry about your fish becomming stranded if something goes wrong. Murphys Law prevails...
My Koi keep the stuff in suspension long enough for the pump to pick it up and send it to the Doc Bio Filter where it is trapped.

 

[Nakish66]

My ponds (for the past 43 years) have done fine without a bottom drain. Depending on how you plumb it, it is possible that your pump can empty your pond and then have the pump burn out.
With submersibles, you never hear the pump, it seldom burns out because it is water cooled, if it is off the bottom by 6" or more, you never have to worry about your fish becomming stranded if something goes wrong. Murphys Law prevails...
My Koi keep the stuff in suspension long enough for the pump to pick it up and send it to the Doc Bio Filter where it is trapped.

So Dr Dave you just have a submersible pump on the bottom and your fish help with the water movement? Or do you have something else helping with the water movement as well? I have a submersible pump in my pond as well. It is attached to the DIY bio filter that I talked about when I first introduced myself in the intro section. it's on a plant shelf though so it's only down 18 inches from the top. I'm going to try and get two of the things that addy posted to get some water movement on the bottom. My fish are not big like yours so I don't thing they keep anything stirred up. Thanks for the post, I already told you I LOVE your yard and your ponds!! Absolutely beautiful!!

 

[DrDave]

Having large Koi in my lower pond helps, I don't need it there because of them. In my upper pond where they are smaller, I use a 3200 GPH pump to provide circulation and that comes from the lower pond so it returns there through the interconnecting stream.

 

[Waterbug]

Nakish66, I'm around in Oct/Nov and always like to talk ponds. I'm by 7th Ave & Indian School.

I would not use a PVC pre-filter with the holes. I think I may have actually used one once and it clogged with string algae. I spent a whole summer once just making pre-filters. One was the size of a garbage can with finer mesh wire the closer you got to the pump. Looked good on paper, looked impressive when built. The string algae was less impressed. It kind of said, cool, great home. The thing was so heavy I could barely get it out of the pond.

Ponds are funny that way. They pretty much never act as you'd expect. And if they do act as you expect, wait a few months.

The only problem I have with pre-filters (of any kind, before pumps, other filters, etc) is what happens when they clog. The foam pre-filters on many hobbyist pump can clog really fast. The extra load wears a pump out faster imo. The impeller and opening in even small pumps are pretty big. The tiny stuff stopped by foam doesn't hurt the pump. You really just need to stop bigger stuff.

I've had good luck with the pump just after the skimmer basket. So really the skimmer basket is the pre-filter, to contradict my dislike of pre-filters. But I was always good about cleaning the skimmer basket and it was made to be cleaned daily. Pulling a pump out, unscrewing the basket and cleaning the foam filter...I'm not so good at. Out of sight out of mind.

As for water movement...it's not really to keep the bottom clean, it's to move the muck so it collects in one spot. For example, in a round pond if you a bit of pump outflow parallel with the pond's side wall you quickly get the whole pond moving in a circular motion and all muck will be moved to the center of the pond. Just like a wheel the slowest rotation is at the center. If there a bottom drain there the muck will go down it and the whole bottom will be clean even if a flat bottom. I do think the bottom should slope a bit toward a bottom in case the pond is ever emptied for cleaning. But 1/4" drop over 12" is fine for that.

A pond itself can act as vortex filter.

A bottom drain can also be used as a fixed in place vacuum.

The valve can be opened for a short time to flush whatever is close to the drain, very close, like 6" max. You can use a pool sweep to push stuff to the drain.

However I find hand held vacuums much more reliable and do a better job. Bottom drains can get stuck with sticks and leaves and really don't do a great job unless the pond is really set up right and the ponder is really good about maintenance. I've seen lots of Koi ponds with good setups and the ponders were really good about maintenance. But in water garden type ponds it's harder. You don't notice string algae growing on the bottom. High end Koi owners can be inside the house watching a football game and hear a leaf hit their pond.

 

[Waterbug]

Nakish66, I'm not sure where you are in the design/build process but the best thing I ever made was a catch basin for the waterfalls.

Here's how it's built.

The splashing is all contain so you get a smooth surface for viewing, but still get the nice sound. Also, when/if you ever get a DOC build up and the falls start making foam the foam is contained in the basin. It's easy to scoop out so kind of a poor man's protein skimmer. Keeps the surface from becoming covered with floating clumps of foam. The out flow at the bottom pushes muck to the far edges of the pond bottom for easier vacuuming. And also kept half the pond bottom clean.


My second favorite feature is mortared rock bottom and sides. I love the look of rock but not the issues. Mortaring the rock down solved all the issues and gave me the look I like. And river rock is so cheap here in Phoenix.