Bottom Drains

[Terri]

Should you have a BD? Why? Most people are detered by these, what I think is an essential componant, because - OMG - you have to cut the liner! Why some find this so scarey is beyond me..? If it's done correctly there are no issues of leaks - and this is the most efficant way to remove waste from your pond.

Comercial bought bottom drains, if you can afford them then buy 'em. Ready to go and easy to install.
Teta w/domehttp://koivillage.com/pond_accessories/images/bottom_drain_4_inch_yamitsu.jpg Spin Drifter w/diffuser dome http://koivillage.com/pond_accessories/images/spindrifter_bottom_drain.jpg

But making a bottom drain is pretty simple. We've done a few.
http://www.backyardpuddle.com/diy/tank2/images/tank2_08_jpg.jpg
Found at your local plumbing/hardware store for a few bucks, the toilet flange. Most recommend a 4" drain, well, a toilet flange is 4". There's a trick to this - you make your own rubber gaskets with leftover EPDM liner - pretty simple, you need two circles cut the "outside" diameter of the flange. These are sandwiched between the top and bottom plates. Using silicon you glue one piece to the top plate and the other to the bottom plate.
http://www.backyardpuddle.com/build/2004/images/2004_10_jpg.jpg
This is handy, as when you're installing the drain the EPDM gaskets keep dirt out of the pipe work. Notice the wing nuts... important part not to over look. Once the cement is cured the nuts remain locked, the bolts are easily undone to remove the top flange for liner placement. We suggest using hydrolic cement for setting DIY drains, it gets into evey nook and cranny as it's consistancy is like that of soup.


More to come...

[Terri]

http://www.backyardpuddle.com/build/2004/images/2004_16_jpg.jpg
Cement is cured and now the liner is ready to be laid. Know where your holes for the bolts are. Below - OMG - the liner's been cut! What you can't see is the little holes also cut for the bolts. At this point silicon needs to be applied generously through the slice around the bottom flange and pressed down to create a tight seal.
http://www.backyardpuddle.com/build/2004/images/2004_18_jpg.jpg
Screwing the flange down. I mentioned before, the top and bottom pieces both have rubber liner, there's a third here now. With the three layers plus silicone, this makes for a very good leak proof "gasket".
http://www.backyardpuddle.com/build/2004/images/2004_23_jpg.jpg
Before screwing the top plate down tight, yet more silicon is added.
http://www.backyardpuddle.com/build/2004/images/2004_25_jpg.jpg

Greg, I was hoping you would add yours to this thread once I've completed my posts.

[Terri]

ACK! There's that knife again LOL
http://www.backyardpuddle.com/build/2004/images/2004_28_jpg.jpg
I know a few ponder's who would be feeling queezy about now... Once the top plate is secure the liner can be trimmed out.
http://www.backyardpuddle.com/build/2004/images/2004_30_jpg.jpg
All done! Pretty painless really... don't ya think? Wait 24hrs and add water.

Every bottom drain needs a cover. Commercial drains come with domes for a reason. The cover creates a pretty good draw along the bottom - without a cover you've pretty much got a whirlpool that will suck from above. Not only that, but it's obvious, a cover keeps your fish from swimming into the drain line. It's recommended that the clearance be about 1" to 1 1/2".
This is the one Ian made, it's concrete and an air diffuser will sit on top once in place.
http://www.backyardpuddle.com/build/2004/thumbnails/2004_11_jpg.jpg http://www.backyardpuddle.com/build/2004/thumbnails/2004_12_jpg.jpg

There's more detail/photo's to this install at http://www.backyardpuddle.com/build/2004/index.html for those who are interested.

If you've got picture's of a bottom drain install feel free to post them.

[ozzyrockman]

Terri, have you made plans for an anti-vortex lid over the top of the bottom drain? Isn't it amazing how after scratching our heads for a while the things we can come up with and toilet flanges are so appropriate for their applications in ponds. :D I am now regretting spending the $$ on the Tetra bottom drain in our however I wasn't thinking then. Oh well at least it wasn't one of those $250 jobbies. Allen

[ozzyrockman]

Ok don't give me time to ask my Q :lol: :lol:

[Terri]

LOL sorry Allen

[Melinda]

NOW she posts what she used as gaskets after I spent 8 dollars a sheet for pieces of rubber big enough to make my own gastets. Wonder if I can return them. Surely I will have liner left over somewhere. hey and did you use marine silicone or hsut the regular old silicone?

[Terri]

Just plain old builders silicone, clear stuff, no additives like mold-icides(is that a word?) that would be used for kitchens or baths. Silicone is in pretty much inert once dry/cured.

[GregBickal]

Here's a couple of teaser pictures of my bottom drains. Of course if you want the DIY instructions, help me out by buying my DIYCD.

First one is a Retro-fit model. Second one is through the liner. Both use the pipe boot method to connect to the liner. I have ideas for a drain with an air line also, but havent had time to work up a model.

[Busy B]

Terri...some info on the Tetra...that model doesn't go thru the liner does it? The piping to it lays on top of the liner? And what kind of pump would function best with it?

Greg...clever guy aren't you :wink:

[GregBickal]

Busy: The above liner drains (like the tetra), should still boot throught the liner, at least 6" below water line. I wouldnt recommend any bottom drain that trys to use a syphon. As for the pump, you shouldnt hook a pump directly to the drain. Always connect the drain to a settling chamber, and then connect the pump to the settling chamber. 2" drain (like the Tetra) can handle 1200gph.

I like the Toilet flange style bottom drains, as they are flat to the liner. With the bowl or cover removed, you can easily seine a pond. I dont like having to pour a cement pad, but I see how it is used to hold the wingnuts.

My new style of bottom drain (no photos yet), will boot right to the elbow. Then it will be only an inch or so above the liner. Still have to use a bowl to cover it, but the bowl doesnt have to be permanently attached and could be removed for maintenance or clogs. Right now, it takes a swim in the pond to clear a hair algae clog, which is a little hard to do in 50F water.

[Busy B]

Just a little hard...:smile:...

I remember the bowl thing now from your CD...do you ever have problems with the plastic breaking down or it doesn't do the same thing it would being outside in the elements and becoming brittle.

I still haven't got all the symantics down on setting up a settling chamber...my pond functions at the moment more of a water garden. If I have enough left in me to start digging again, I need to figure it out.

[GregBickal]

I havent seen the plastic break down. Out of the direct sunlight it should be ok. I use Squirel baffels as my drain covers and they have lasted 6 years. You could just pour some out of cement too I suppose.

[Terri]

I guess Greg answered your question... I'm not needed ... :cry: (j/k)

Tetra does make a 2inch "retro-fit" bottom drain http://www.ponds2go.com/photos/16361-2T.jpg
this would sit above the liner along with the pipework. I've personally never seen this done, I guess it's an alternative to those who are not willing to cut their liner... if they work as well as an in pond BD, haven't a clue - I would think the retro-fits would work more like a muck vac...

Hey, if anyone's got a retro-fit BD install to share, I'd like to see it :grin:

[Jackie Ramo]

I don't have one but have often thought of installing one. They have come recommended to me but at the moment I can't remember who...

[Sandi_W]

Terri,

What type of air diffuser did you use and how did you attach it? Got a pic of it?

Thanks,

Sandi

[Terri]

Sandi, Ian made an air ring out of tubing, the hard tubing used for soda machines - but air line hose will work too. Just need a pin and a lighter, length of tubing and a 'T' fitting, with the concrete cover you can actually embed the airline(diffuser) in the molding process, but if done after the fact you could use stainless steal clamps and screws to attach it down... means drilling the concrete.

I think I have a photo somewhere of the air ring made of tubing... will see if I can find it.

You can also buy 6", 9" and 12" round air stones or rubber membrane diffusers. The airstones have enough weight to hold themselves down, the membrane however would need to be fastened in some fashion.. most have a threaded fitting located on the underside to attach to drain lids.

[Sandi_W]

Terri,

Thank you for your help. I was thinking about a disc diffuser. I am doing a diy retro drain and trying to figure the best way to add the diffuser to make it the most effective.

Sandi