Jbuda,
Since no one else wants to answer this question I will. What is required is a valve that can be opened or closed where the bottom drain pipe ends outside the pond. On this piping system a way to blow air into the pipe system needs to be installed. The best place to install this air injection system depends on the design of your system. Once the water is blown out of the bottom drain pipe air is trapped in the line and it will not freeze no matter how cold it gets. If you let me know what your plumbing system is going to look like I will tell you how I put this air injection system into it.
Mike

mike,
thx for the info. It makes since to me what your saying and I can do it, but I'm still a little leary about cutting a hole in the liner. If for some reason it leeks,I don't want to have to redo it all after I REDO this one. I have a 1500 gallon pond right now but it's in a bad spot.
Jeff

Jeff,
What manufacturer BD do you plan installing? Having installed well over a hundred bottom drains with no problems with any of them.(knock on wood) There are some that are far easier to install than others. A skimmer is far more likely to leak then a bottom drain. Is this drain going to be connected to a pump, a settling chamber, or a skimmer?
Mike

i was looking at a cheaper one, tetra drain.
i was going to have 2 SC with filters in the first and a fine filter and the pump in the 2nd, i also thought of have the water from the bottom drain to the lower part of a 55 gallon barrel acting like a skippy( so i could keep the pipe from freezing down so low) then to a 30 gallon tub with my pump, then to a couple of smaller water falls.
I will also have another pump in the skimmer going to a 55 gal skippy.
thx jeff

Hi Jeff,
By far the Tetra 3" bottom drain is the easiest to install and the least likely to ever leak. It is the drain that I like the best. The problem is the drain is only a 3" drain and the three legs on the lid. Depending on how much water you are wanting to move through the SCs a 3" pipe may not be large enough to move enough water by gravity. Yes you can connect 4" piping to the 3" drain to move more water. Because of the three legs they can catch debri and cause the drain to clog. But probably not any more than any other drain that is run by gravity.
The next thing is what do you have that produce controlled moving air. It can be an air compressor, leaf blower, air output on a shop vac, or an air pump. Depending on the depth of the pond will determine if your devise will work. Once I know what kind of devise you will use to blow the line out I can tell you how to plumb it.
Mike

I will try to use a 2000 gph pondmaster mag drive sub. So I figure it will push about 1400-1500 gph and the pond will be about 3 feet deep at the drain.

I have an air compressor and a 200 mph leaf blower.

do I just put a valve near the top by the SC and shut it as I'm blowing it out?
thx jeff

Jeff,
Depending on how far your running the piping a 3" pipe should be fine. To do the plumbing a valve should be installed just before this pipe goes into the SC. Some where in the pipe before the valve install a tee in the line. With the branch pointing up reduce this branch down to 1/2" pvc. Extend this pipe up so that the end is at or above water level. Install a 1/2" ball valve. It is easy to make a fitting so the air compressor can be connected. This fitting is made with the following parts and are connected together in the order listed. A short length of 1/2" pvc pipe, a 1/2" male adapter, a steel 1/2" to 1/4" reducer, and a 1/4" male quick disconnect air compressor fitting. The 1/2" pvc pipe will glue into the slip end of the male adapter. The male threads on the adapter will screw into the reducer. The male quick disconnect will screw into the 1/4" end of the reducer. When you want to winterize the drain line you will do the following procedure. The air fitting you just made will slip into the 1/2" ball valve. It does not need to be glued. Your air compressor can be connected to this. The output air pressure on the compressor should be turned down to 10 psi. Close the valve on the bottom drain line going into the SC. Open the 1/2" ball valve. Turn the air compressor on. When air bubbles come up from the bottom drain close the 1/2" ball valve. Be careful the air fitting may pop out of the 1/2" ball valve when you first close it. Leave the two valves closed and turn the compressor off and disconnect. The line is now empty and will stay empty until the valves are opened when you start things back up in the spring. The leaf blower might work with a larger then 1/2" pipe setup if it can build 1.5 psi of pressure.
Mike

mike
I went menards today to see what I needed for this. It seems pretty easy, so I'll see when it comes closer to doing it how brave I am to try.
thanks for the info, Jeff

Jeff,
I remember the first time I installed a 3" Tetra bottom drain. We dug the pond to depth of five feet and the ground was pouring into the hole. I had a choice to make and that was put the Tetra 3" bottom drain in under water or fill in the bottom of the pond with at least a foot of dirt. The customer wanted me to try and put the drain in. So I dug a hole in the bottom of the pond so I could pump the water out while cemented the drain in place. That worked somewhat. The concrete had to set basically under water. The next day I pumped the water out and filled the hole in the bottom of the pond with dirt and then put the liner in the pond. At that time it was time to attach the top plate on the drain. By this time there was 6 inches of water under the liner. Luckily this bottom drain doesn't need to be caulked. So I was able to push the top down to the base and run the screws in. That was over 13 years ago and that drain never has leaked at all. The Tetra drain is the only drain on the market that could have been installed in these conditions.
Mike

mike,
I shouldn't have that problem, I'm going down 30-36 inches and will build up the edge about 6-10 inches. I have about a foot of BLACK dirt and 6 feet of sand below that.
I have a couple questions.
How much concrete do I set the drain in?
How close to the top of the drain can I get the concrete?
How much of an angle can I run the pcv (10 ft.) from the drain?
Can I put the liner down with the concrete still wet?

Thats all I can think of at this moment
thanks jeff

Jeff,
One bag is more than enough. The concrete is used just to keep the drain level if you happen to walk too close to the drain in the pond. With the concrete the drain won't move.
I install the bottom of the drain with the top plate on it with the screws in it and run the concrete right up to the top edge of the top plate. When the concrete is set then I remove the top plate and remove any concrete on it.
With a SC system you are probably not going to move enough water fast enough to keep any of the debri from settling out. So once in a while you are going to have to shut the valve going into the SC and empty the SC. When you open the valve going into the SC the water is going to move a lot faster and flush this debri out of the piping. Answering your question is not possible without a lot more information. The answer is dependent upon the length and angle of the piping and the size of the SC.
At menards they sell a product called instant post cement. This sets up in ten minutes so you can install liner almost immediately after cementing the drain in place.
Mike

mike,
I'll have a 10 ft pvc from the drain to a 45 up about 4-5 ft to a 90 into the SC. With the SC, I'm thinking using a couple of storage bins. One for the filters and one for a fine mesh and the pump. I have been looking at doing something like cliff and joannes design.
thanks jeff

mike,
also could I put a cap on the 1/2 inch and drill a hole maybe 1/8 or 1/4 inch and blow the air in?
sounds like you would want to blow air in and let the water rush back up to help clean out the drain pipe.
thx jeff

Jeff,
Based on what you have said about your piping including fittings the total length of pipe is 34 or 35 ft. This does not include any fittings to connect on to the SC or the valve and tee. So I would guess that your finial plumbing you end up about 45 ft of pipe with all the fittings included. Assuming everything is 3" pipe then at 1500 gph the drop in your first SC will be about 1". The water in the pipe will be moving at a rate of 68 ft per min or .78 mph. This is fast enough to carry lighter debri up the 45 degree incline but the heavier debri will fall out of the water column. When flushing the pipe as above the flow will be at a much higher rate depending on how much below pond level the pipe exits into the SC will determine how fast that water will move. The second question is does the SC have enough volume so that once the water in the pipe is moving quicker can that debri make it out of the pipe before the water slows down again? To determine all this I will need the size and dimensions of the SC, how far below pond level the top of the 3" pipe will go into the SC and how far below the top of the SC the top of the 3" pipe will be?
Your second post you talk about emptying the pipe and refilling the pipe to flush the debri. This is probably not going to do more than flushing the pipe I talked about above.
Mike

mike,
My basic plan right now is to have 2 31 gallon rubbermaid tubs as SC, with the top being about 1 inch above water level. The 3" coming in will be about 12" below the water level or right near the bottom of the tub. So with this the rise of the pipe will be about 3 feet up at a 45 to the side of the tub. So I will have a 90 under the drain(about 12" below water level) then 10 feet to a 45 up to the Y where the air blow out will be, then the valve (back-back-back with these 3) then another 45 into the tub at the bottom right side. A 3" into the 2nd tub near the bottom where the pump will be.
This will be under a 5X10 deck about 3 feet from the pond behind the skimmer. I hope this explains what I plan, if I'm missing something let me know.

Thanks Jeff

Jeff,
Based on what you have given me above I can now say how well your system will work for flushing the line out. With the first SC empty when the inlet valve is opened there is enough room to hold 12 times the volume of the piping from the base of the incline to the SC. It will start at a speed of 4.5 ft per second which will be fast enough to lift most of the debri. It should be able to keep a speed of 3 ft per second for 6 times the volume of the piping which should be fast enough to just about anything out the pipe except for gravel. I would want the inlet to come into the SC about 4 inches off the bottom to have some settling. I would also think about a baffle in the SC to get as much debri as possible to drop out of the water column.
Mike

mike,
Thank you for the info. You have answered alot of my questions and made me feel better about doing this. Now I have too wait until the ground thaws, hopefully soon.

Jeff

Thanks for the info Mike in Chi-town!

Like everything with my pond it has been a definite bone-headed trial and error project.

For example, I have no bottom drain and koi. Already know that next year I am going to be installing a couple aqua art retro drains to handle the mess the koi make. As I live in zone 3b winterizing the bottom drains will be critical.

Mike, if I read what you wrote correctly, putting a valve before the s.c./filter set up and then another t'd off it to use to push air into the bottom drain line as you described will create some sort of air lock once the valves are closed and water can't push back up the line through gravity feed? I wouldn't need to add another knife valve where the bottom drain line will come through the pond liner below ground (about 4' down from ground level)?

Also, using this method, it would seem no air is in the bottom drain line so - as you said - it can't freeze. But, I also noted somewhere you recommended as a rule of thumb flex pvc for below ground and rigid pvc for above ground. Is the flex pvc still necessary if the water is going to all be pushed out of the line for the winter?

Thanks, Jenny

I was tooo chicken to cut a hole in my beautiful new liner when I dug my pond 10 yrs ago. I put a 3" PVC pipe boot through the wall to my SC at about mid water depth. I can hook up my retro drain (DIY), or run from midwater intake. I like having the option to pull from mid water when the temps are still cool.
To winterize, I pop off the pipe to the BD on the pond side, and attach a 3" elbow with a stick of PVC that reaches past the surface. Then I pump the SC empty. I admit that there have been years that I did not get this done before the pond froze, and even with everything hooked up, I have never had anything freeze and break.

I am not saying that I have the best way of doing it. Just that it works for me.

Here is a link that might be useful: my DIY BD

Hi Jennie,

Thanks for the info. I had to smile when I clicked on your link because I've already been to your site quite a few times while I've been researching bottom drains. In fact, I had decided that I'd ditch the aqua art retro drain idea and just do a diy bd because it is going in to a 6' deep area of my pond and really who will see it down there anyway! After looking at a lot of diy retro drain diagrams and instructions, I decided to go with your design because I liked the concrete to add weight to the thing.

You wrote that you pipe booted the bd at mid water depth. How deep down is that for you? For me, that would be about 3' and I'm pretty certain I couldn't reach the midwater intake by reaching in from ground level....even if I was lying on my tummy to maximize my reach. Having taken a dip in the water last October to do some plumbing work, I can tell you that is not something I'm looking forward to doing again ever.

As you're in zone 3 and know cold winters like I do, I'm gonna say your depth for the mid water return will probably work for me too. I am comforted by your statement that you've never had any problems with freezing.

Thanks for your help, Jenny

PS with the cement in your bottom drain, do you have a hard time pulling it out of the water because of the weight?

I have the Tetra 3" drain. Installed it after a couple of years operation and got tired of cleaning muck all the time.

For winterizing I remove the mushroom cap and insert a 3" Test Titan plug and tighten it. It is, shall we say, exhilarating in November and March to strip to the waist, lay on a board laid across the pond, stick my bare arm down through 2-1/2 feet of 35-degree water, and insert or remove the test plug.

After the plug is tightened in November I use a shop vac to suction the water from my vortex filter and the 4" pipe under the pond.

After removing the plug the hard way for years, I've decided next year I will try flooding the pipe with water before removing the test plug in March; the pressure of the pond water and the suction from the empty pipe make it tough to pull the plug.