Jeff,
Located in the Twin Cities, MN. Contact me and I can help with questions. Should be lots of photos of my pond construction at the link below.

Here is a link that might be useful: JJ's Water Garden

I am farther north than you and I do not run my pond in our long winters and -20C temperatures from December to the end of March. I do have a bottom drain (over the liner retrofit). It works fine and I pull it in the fall for the winter so don't have to worry about it freezing. I did have a real bottom drain that I had capped, drained etc. but it still froze in the pond so had to replace liner everything...long story. I use external pumps, sc from the bd and skimmer to waterfalls. In the fall I drain the waterfalls, sc and the water from the lines then pull the pumps. I do not drain pond or skimmer and have never had any issues with rock movement or skimmer freezing. My fish come inside for the winter and I lost three fish in their indoor pond this winter to old age and an amonia spike. Never have lost any in the transport out to the pond or back in for the winter. My fish (goldfish, wakins, shubunkins, sarassa comets) are still inside as pond restarted last week and the pond water temp is only 62F. I move the fish and their 300gal pond water at the same time and use the filter media from the FluvalXP on the indoor tank to jump start my pond. Finally have days off next week so the fish go out on Monday. Have fun building your pond. Bigger is always better.

Jalal:

first of all is "sc" a setteling chamber ?

I plan to do goldfish only - do they get sucked up by the bottom drain ?

How does the retrofit bottom drain compare to a regular through the liner bottom drain ?

Thanks
Jeff

Hi Jeff,

I'm out on the prairies of west central MN so I know all about freezing too :)

My ponds are smaller, 5.5'x5.5'x32" and 6'x4'x18". I overwinter all my hardy plants in the 2 ponds, and all the fish in the deeper one with an aquarium air pump and a stock tank heater. I cover 1/2 of the pond with the fish in it with a sheet of foam insulation board to cut the 'windchill' factor. I bring my 'tropical' plants inside and set them in a sunny window in a couple big tubs. I also bring my pumps inside so the waterfalls are shut off for the winter. I tip the skippys on their sides so they empty and hose off the filter media in the fall. All my 'plumbing' is above ground so is drained or brought into the basement so I can't help you there.

Each pond has a 'skippy' type filter with a submerged pump running into the skippy and back down into each pond via a small waterfall/streamlet. Lots of plants and a low fish load (15 goldies/comets total) and I have very clear water. I feed the fish sparingly and they graze on the algae on the sides.

My tips:
Go with the bottom drain. I will if I redo mine. If you want less maintenance do it now. I recommend enjoying your little piece of paradise instead of working on it all the time.
If you don't want your fish to produce a million babies each summer don't put in alot of 'oxygenators' (submerged plants like anacharis).
I would consider external pumps for easier maintenance as well. And make sure you buy a bigger pump than you think you need. By the time you go through pipes, hoses, filters, waterfalls etc. you're down to a trickle if you aren't moving enough water.

Having done this before you no doubt know all this. But remember bigger is better :) My first ponds were done very low budget and I love them, but........ I always dream of more!

{{gwi:180641}}

Sorry. SC is a settling chamber. Mine is a 4 x 4 square, 42" deep with the bottom like a triangle cone to the centre-about 12" up from the bottom. The chamber is lined with 2 x 12 green wood for support, carpet over that then liner. I used pipe boot fittings for intake and discharge. My retrofit drain is very simple. All it is is a 12" plastic bowl with 4 sections cut out from the bowl rim to 3/8"--leave a 3" section, cut a section. The parts that are left act like legs. In the bottom of the bowl I cut a 4" hole and have a 4" piece of ABS pipe through the hole sticking down about 1" into the bowl. I think there's a 4" 90 after that then 4" pipe to the side of the pond, a 90 elbow to go up the side of the pond to 24" down from top of pond and a pipe boot fitting through the side wall of the pond. I reduced the 4" pipe 8" through the side so that I could use a 3" knife valve as they are cheaper. It's only another foot of 3" pipe before it goes into the sc 24" down from the top of the sc. This is a suction type drain and well it doesn't do as large a sweep as a through the liner bottom drain it still collects crud of the bottom of my pond. Yes small goldfish do go up the pipe the biggest that's ever done the swim was 5" long. My sc is 300 gals and I have one of those cone type filter things on my discharge pipe to keep any fish from going through that line and into the pump. I have a fernco fitting on the pond side so the pipe slides in, tighten the fitting and it's set to go. In the winter I put a threaded 4" cap in the fernco, drain the line to the sc and cap the sc side.
Aquaart sells a retrofit bottom drain that's has great reviews on the koipond site. I want one of those as would have better suction but finances currently dont allow for it.
I overwinter all my plants in the pond including water lilies but my pond is 42" deep in the deep end where the water lilies go for the winter. Everything else stays on the shelves along the edge.
One thing I wish I'd done differently on my pond was to make a coping edge beyond the plant shelf edge that was just wide enough for rocks to hide the liner and be partly immersed in the pond. I did that in some areas but in others I didn't and have rocks stacked on top of each other on the plant shelf to hide the liner. The problem with this is that alot of crud gets in those rocks on the shelf edge and it's a pain to clean each spring. Other than that I'm happy with my system. Can post pics if you are interested. Patti

Jeff,

I live a little bit south of you and I have installed hundreds of ponds. A lot of this have bottom drains. I would never install a above the liner bottom drain in a new pond construction. I have never had a leak or pipes breaking due to freezing. The key is to be able to remove all the water from the piping for the winter. Empty pipes do not break due to freezing. Leaving a skimmer empty for the winter or the pond level low for the winter is the worst thing you can do. I can't tell you how many skimmers that I have seen lift or pop out of the ground because the water level in the skimmer was lower then the water in the ground. One rule of thumb that I use is flexible PVC below ground and rigid PVC above ground if possible. Flexible normally will tolerate freezing with water in it one time and will scatter the next time. This can happen in one winter if it freezes and thaws twice in one winter. To provide more information I would need more information as to what you are planning and equipment that is being used.
Mike
Mike

Mike,
Have you noticed any issues with SpaFlex (flexible PVC) that is drained but going through the freeze cycles? I have three 2" lines that are buried but come up through the ground in the pump house. The top end is drained but areas below ground will still have water in them. One line is connected to the skimmer and is buried between 12" to 18" on the end where it connects to the skimmer. Our freeze can penetrate up 36" in winters like we just had. The snow pack helps insulate but still can go deep.
I've been under the theory that as the ground freezes with water in the hose the pressure is consistant inside and outside as the ground is freezing first and containing the expansion. What are your thoughts?
JJ

Jeff Mike has good advice on through the liner bottom drain install. Mine did not have the recommendations he has for blowing out the water in the line. Tried capping it but water got in the line and the pipe cracked. My frost line is also 4 ft deep and winter temperatures here are brutal. Consult with Mike on proper construction for through the liner drain and winterizing and you'll be fine. They work way better than my retrofit drain. I only have goldfish and massive filtration is not as big an issue for me. I am glad I have the retro drain though as it does collect a lot of crud and I don't have to get in the pond to do bottom cleaning!

Wow - thanks for all the suggestions . . .

Shepco - nice photo - your pond is beautiful

Patti - if I understand; your Setteling chamber is made from scrap liner material ? I can picture the plastic bowl with slits (did you add weight to hold it down). Could you explain the cone filter thing to keep this fish out of the pump? How do you clean the SC ? Is there a drain ?

Mike: You mention that you should drain all the water from the pipes . . . how do you do this with a bottom drain ?

Jeff

We are redoing our pond this year. It's already 15 X 8 but are going to make it 20 X 25. We leave the water in the pond all year. We heat the water in the winter and have an aerator in it. Have never lost a fish yet. We have koi and goldfish. The one koi is 22 inches so it's impossible to bring it in the house. We heat it with a farm water heater some years maybe two of them. Actually it's not very expensive to heat it. Of course the elec bill is a bit higher in the winter but the koi are worth it. We can sit in the gazebo and watch them for hours. They even eat out of our hands. AMAZING!!!!

Diygal,

Lets look at how freezing happens in the ground. The ground freezes from the surface and then down into the ground. So the water near the surface freezes first. If it freezes at both ends of the pipe this ice will act as a plug in the pipe. As the it continues to freeze deeper in the ground more water in the pipe freezes. As water freezes it expands. If it can't push the pressure from the expanding water turning to ice out an end of the pipe the pressure increases in the pipe. This pressure causes the piping to stretch. The pipe will grow in length. When the pipe thaws out it will not shrink back to the size it was. This is why it can usually freeze once with no problem other then the pipe being longer. The next time it freezes the pipe can't stretch any longer and breaks. I have seen a pipe that is 30 ft long grow about 2 ft in length. Take a shop vac and vacuum the water out for the winter.

Jeff,

You can't remove the water from the bottom drain line but you can use air to push all the water in the pipe back into the pond. Then by trapping the air in the pipe water can't enter. Yes the air that is in the horizontal pipe under the pond can get out and into the pond. The air in the pipe going up hill can't get out. The pipe under the bottom of the pond can't freeze. The only way it could for the pond to freeze solid and it won't. But let say it does. The ground is going to freeze fast so the water that is in the pipe where it goes up freezes first. With the drain being open the expanding ice pushes the water back into the pond. Since it is going to freeze from the outside to the center it is going to push the excess water into the pond and the pipe will be okay. Very little if any pressure would build in the pipe.
Mike

Mike: You certainly bring an interesting solotion to the table. I never thought about using air pressure to push the water back into the pond. I'm assuming I would need to make some type of pipe cap that has a Schrader valve (like car or bicycle tire valve) and use my air compressor to blow air into the pipe ?

Do you build ponds as a business ? Do you have a preference as to brand of bottom drain ? What about the setteling chamber ?

Jeff

Jeff,
Yes I do build ponds for a living. I have built ponds in seven states so far. I have built four ponds in WI. There are easier ways to pressurize the line. I usually install a valve on the drain line that can be closed to keep the air pressure in the line. Then it just become how do you get air into the line. I usually install a tee in the line between the valve and the drain. I reduce the branch down to .5 inch and install a ball valve. Then it becomes simple to hook an air compressor on the open end of the 1/2" valve. Once the bottom drain starts to bubble air the 1/2" is closed and air is trapped. If you use a ball valve on the bottom drain line you have to get the water out of the ball in the valve.

The bottom drain I use depends on where the water from the drain is going. If a pump is going to suck the water through the drain then I always use a 3" Tetra bottom drain. It is by far the easiest to install and almost mistake prove. If it is going to gravity feed a sc then I use a 4" bottom drain. Then the piping has to be sized to match the flow needed.

SC's that are set up correctly can be good for what they are suppose to do. The problem is most sc's are not set up correctly.
Mike

Wow - I've got some thinking to do now ...

Next, please tell me a little about Settling Chambers . . . I find almost nothing seaching the internet

Jeff

Jeff,

First let me tell you what a SC is suppose to do. The bottom drain is collect and remove any debri that is in the pond that is heavier than water. This heavier than water debri is moved to the SC where it is suppose to settle to the bottom of the chamber where it can be removed. They are normally setup so that the water comes into a round sc at an angle so that the water moves around the outside of the chamber until the debri falls out of the column of water. The reason for letting the debri settling out instead of removing it with a basket in front of a pump. If the debri gets into the pump will break up some types of debri. The main type of debri wanting to be removed this way is solid waste from the fish. By removing the solid waste this way the bacteria in the filter doesn't have to break down debri. This is way they are suppose to work but most do not. Most do settle debri out but not the debri that we are trying to remove. This debri is very close to the same weight as water. It is very fragile and had to see. The only way to remove this debri is for the water to move very slowly and for a long time before leaving the sc. If the water moving through the piping to the sc is moving to fast it will break this debri up. If the water is moving too fast in the sc it will not settle out. If the outside walls of the sc are not smooth they break this debri up. The shortest period of time that the water should be in the sc is 20 minutes. The water has to move from the bottom drain to the sc needs to move by gravity. As an example if the sc is 200 gallon then the max flow to the sc is 600 gph. With this flow rate then the drain is only going to remove debri from a very small area. Moving water through it faster than that the heavier debri will settle out and it will look like the chamber is working great but this is the same debri that a pump basket would catch just fine. If I had to guess I would somewhere over 90% of the sc's are not doing what they are suppose to do. This is why I seldom use settling chambers. To get an sc to work correctly then the best way is to build the pond to be a sc so that the drain can remove it from a very short distance from the drain. But this leads to other problems.
Mike

That all makes sense Mike . . . I guess I don't need the SC to seperate out the fish poo - I think I just want a simple and consistant way to keep leaves from accumulating on the bottom of the pond.
How well does a simple leaf trap work in a pond ? I am envisioning a bottom drain connected to an external leaf trap by a 2" or 3" pipe. The leaf trap would be connected to a 700 GPH external pump. I would locate the leaf trap and pump in some type of enclosure burried in the ground to make it self priming. I would remove the pump and leaf trap and fill the drain line with air for the winter as you previously explained.
The filtration would be done by the skippy - I have full confidence in them. The side skimmer and bottom drain/leaf trap would just remove leaves and large whatever from the system.

Am I on the right track ? Of is there something better than a leaf trap ?

I really appreciate your advice - thanks

Jeff

Jeff,
The leaf basket will catch anything bigger then an 1/8". But I would suggest a larger pump then 700 gph. That small a pump is only going to remove debri from a close area to the drain.
Mike

Mike: I was envisioning the entire boottom of the pond to have a slight slope toward the bottom drain. Maybe 1" to 2" per drop per foot. just enough to cause anythng on the bottom to gradually drift over to the drain. I could still use a larger pump though - what would you recommend ?

Jeff

Jeff,

Unless you have very large fish in the pond they isn't going to be a current to carry the debri to the bottom drain unless you have an outside source creating a current. Yes I would suggest a larger pump. At 700 gph the water is going to be moving so slow in the pipe from the bottom drain to the pump that the debri will drop out of the column of water.
Mike

Thanks Mike, you've given me alot of good advice. Maybe I'll run my whole pond and filtration design past you before I start construction.

Jeff

You can split the effluent so that a lower amount goes to the bio filter(to keep the bacteria Happy) and cycle the balance back to the pond.