Do you have or recommend a BOTTOM DRAIN in your pond?

Now that I am getting ready to replace my smaller pond (already gone) with a bigger one (the small back hoe came late last fall...), I am considering a bottom drain to put in with the new construction. I was wondering how many of my DG family water gardeners actually have one.

Would you would recommend a bottom drain to anyone else starting up a larger pond?... Also, are there any problems you have had with it and/or any recommendations if you were to do it over again, such as pump size, brand or type of bottom drain, etc...

Thank you. Your comments and help are so appreciated.
RatherB

RatherB, I don't have a bottom drain, but I wish I did! It would have to make cleaning out the pond so much easier.

Ditto crazy4brugs. I don't have a bottom drain either, but I sometimes wish I did. I compensate by placing a sump pump which has the water intake flat on the pump bottom, directly at the lowest point in the pond and pumping water out from that point. I do this twice a year when doing a cleaning, spring and fall. I also use a pond vacuum from time to time. That works quite well but a bottom drain would be much easier.

I also have some rocks in the pond bottom. That would not be possible with a bottom drain. There are two schools of thought about rocks in the pond. One school says rocks allow pockets for debris to accumulate. Debris accumulation provides places for bad bacteria to grow which can make fish sick. No rocks allowed!

The second school says allowing some rocks ( not too many) is beneficial because they provide a constant source of beneficial bacteria, nitrobacter and nitrosomonas, necessary for pond filtration and ammonia removal. This bacteria can survive over winter on the rocks in the bottom and allows for quicker start up of the nitrogen cycle in the spring. Your biological filter gets cranking much faster in spring start up. Nosing around the rocks also gives the koi something to do too. They really rummage around them. Thus - Rocks allowed!

So choose which method you want. If you go with a bottom drain maintenance is a snap. If you don't, be prepared to find an alternate way to keep the pond bottom clean, either with a pump placed at the bottom periodically or pond vacuum or both. If you get the urge to place some rocks here and there for a more naturalistic appearance, make sure that they don't leach anything to change the pond's pH, that they have completely smooth surfaces to avoid scrapes and above all, don't overdo.

Decisions - Decisions! Have fun either way.

I googled bottom drain and looked for some time for actual diagrams on how this thing works without any luck. Guess I am what you call "computer challenged" I am absolutely convinced that I want to put one in when I do my "real" pond but need to know what is involved and how to do it correctly. Anyone know of a good site?

Here ya go!

http://www.koiclay.com/diy/pg4.htm

Thank you for the link! That is what I needed.

I have two bottom drains in my pond and would highly recommend it. I built my first pond in 2005 without bottom drains and had a rock bottom. I had nothing but trouble with it that first year. I tore everything up in 2006 and started over. I added the bottom drains, two mechanical filters and swapped out my submersible for an external pump. I also removed all the rocks except for along the edges so the liner doesn't show. My pond has been a dream come true since then. It is nearly maintenance free and water clarity is 100% improved. I also don't lose fish anymore (first year they all died one-by-one.) For ME, I believe the difference was 100% the result of the bottom drains, but I know there are plenty of people who have thriving ponds without bottom drains so I'm certainly not saying this isn't possible. It just wasn't possible in my yard I guess.

The only downside to bottom drains is, if you shut down in the winter, you need to make sure you can shut the drains off and drain the lines. Also, a bottom drain is best if it is plumbed to a mechanical filter, then to a external pump (it can be done with submersible and skimmer but it's not ideal as the skimmer will need very frequent cleaning) That's only a negative if you don't have it in your budget to replace your pump. If you do, then external pumps are generally a better investment - they last much longer and generally cost less to run.

Songs, what resources would you recommend to get specific info about the systems that are available and diagrams of them? I did a web search and did not come up with much.

Thanks to all of you that have shared info, websites, and personal experience. I really appreciate it so far. The depth of all of your experience really shows. The site www.koiclay.com, in addition, did have a lot of info on building filters, too. I have saved this site for that too. Thank you, Snapple, for that one.

Yes, if anyone knows of other systems and diagrams, I would encourage you to post.
Thank you for all the interest, thus far.
RatherB

The link below provides a good overview and includes pictures. Oddly enough, considering the benefits of adding a bottom drain, it IS difficult to find good information on them. When I redid my pond, I spent a lot of time in the pond forum at Gardenweb (I didn't know about DG then). Back then, the forum was far more active and lots of great information could be found. GW has really gone downhill over the past couple years and I seldom go there anymore, but I do owe much of my bottom drain education to the knowledgeable people who used to post there. (I'm sure some of the good ones are still there, but the forum is not nearly as active as it was)

I have also heard that Koiphen.com is a great source of pond-building information. From what I've heard, the community is made up of some really serious koi keepers so some of the information could be overkill for the average garden pond, but many people have said it was helpful.

Hope this helps.

http://www.aquaticpondsupplies.com/bottomdraininstallation.htm

RatherB, your link does not work. I tried the Koiclay site and could not find anything about filters.

It worked for me.

Songs, thanks for the additional site. The more with photos, the better, to visualize all of the components...

If my larger oval pond will need two bottoms drains, they are both connected to the filter box...and after the filter box I would need my pump in line (within the biofilter water fall) to pull the water through from the drain, to the filter box and then to the biofalls...
Am I thinking this through correctly?

Also, if I have a skimmer, I would have a separate pump that would circulate the water being drawn into the skimmer which will be pumped also to the water fall...?

I am also trying to picture where to place the filter box for the bottom drain...is this at level with the pond, but also hidden somewhere behind the shrubs, or I will need to construct something creative to hide it. I would imagine that this filter box would keep the biofilter pads, etc cleaner by having the first filter box, or do you just send all of the water to the biofilter?

I want everything to look as natural as possible, so hiding all of mechanics is important to me. Where do you all hide this filter box?

Before I start, I want to have a detailed diagragm and supply list ready to do the job as neatly and efficiently as possible. When I construct this, I hope to take photos, including the PVC lines before they are buried.

Going larger was not as simple as just digging a bigger hole...much to be considered to keep the water as clean as possible. Better to do the thinking upfront...
Thanks everyone...as much input as possible is appreciated by all of you with expertise.

This is my 15 by 20 foot hole. I still need to dig ledges for the stone sides and bases for the larger rocks. I have my Japanese Black pine and Japanese maple, as well as the weeping cherry as my existing landscape. My pond that I removed was made of three smaller ponds that were connected with a spillway. They were preformed liners.

Thought I would insert a photo of where I want to use the bottom drains. It looks like it would be best to have two drains.

Thanks again, everyone...

RatherBe,

It sounds like you're off to the right start. I have all the same equipment you are talking about (two bottom drains, filter box, external pump, biofilter and skimmer) so I'll get some pictures of my set up and post them later today.

I do not have a separate pump for the skimmer - I plumbed it to the same filters the bottom drains are plumbed to and the external pump draws from both barrels. But you can certainly have the separate pump too.

The filter will determine the water level in your pond so it is important to make sure it is at the level where you wish your pond water level to. My filters are a tad lower than I want my pond water to be at, so that was a lesson learned the hard way.

Here's a couple of random thoughts/questions:

What size bottom drains are you getting? I have 3 inch and I don't have problems with them, but many people suggest 4 inch is better.

What size pump do you have?

Will your filter have a drain for easy cleaning? What are you using for a filter box?

I know that I will need to get a larger pump, so I don't have that yet. I would prefer a submersible pump, but that is based on what I was comfortable using before . If my calculated needs require an external one, that will new for me too, as well as how to hide it.

I do not have the filter box yet, but only the bio-waterfall filter box and the skimmer so far. I saved the site above in the thread that shows how to build a filter box for a koi tank. But they seem large and I cannot think of how to hide it. From the amount of debris that the filter box must process, I would think an easily accessible port for draining would be helpful. Is yours? Do they sell a filter box for connection with a bottom drain commercially? Is your easily hidden? I am trying to picture how this effects your water level.

Songs, if you can post a photo or more to show how yours flows, I would find that extremely helpful and most appreciated. Thank you. I am sure others that are thinking about this feature will appreciate it too.

RatherB,

DH built a small shed to house my filters and pump. The spot was ideal because the ground just dropped off several feet where the shed is. So we took advantage of the slope - the front of the shed is set on the top of the slope and the back is at the bottom of the slope. This allowed us to essentially house the filter barrels and the pump in the "basement" of the shed. The floor of the shed has removable panels to access the filters and the plumbing. In addition, the back of the shed has two large doors that open wide for full access to the filters and pump.

Here is a picture of the bottom drain and skimmer lines (3 inch pvc) connecting to the filters. I have 3 inch ball valves on each line so that I can shut off the flow to the filters for cleaning.

My filters were made from 55 gallon barrels that I bought from coca-cola for $5 each. (I didn't make the same filter box that was on the link I sent you). There is a rack in each barrel about 8 inches from the bottom, and then I layered 4 pieces of filter pad (cut to fit very snugly) on top of the rack. The water comes in above the filter pads - the solids get trapped on the pads but the water flows through. A lot of filters are designed so that the water comes in on the bottom, solids settle and the water rises up through the filter material and the pump draws from the top of the barrel instead of bottom. This has some advantages (filter pads don't get as clogged because solids are not on top of them) but I like my setup because it allows the fish and frogs a safe place to "land" if they decide to take a trip through the bottom drain lines. (Which the smaller ones frequently do, especially in the spring when I first start up the pond. They seem to learn after a while and then start avoiding the drains.) With my setup I just scoop them out with a net and toss them back in the pond.

Each filter barrel has a drain at the bottom (2 inch pvc with knife valves) for easy emptying and cleaning.


This message was edited May 4, 2008 1:02 PM

This is the plumbing in the back of the filters to the external pump. Each line has a ball valve (2 inch) so that I can shut off flow to the pump individually.

The reason these barrels determine water level is because water seeks it's own level. If the barrels are lower than the pond, gravity would force the water to keep overflowing the barrels until the pond level matches the height of the barrels. Likewise, if the barrels are higher than the pond, the water level in the barrels will never go higher than the level of the pond.

This message was edited May 4, 2008 1:10 PM

This is a bad picture (but the only one I have) of the trench for the bottom drain.

So that's how I hide all my filters and plumbing. I realize that a shed might not be feasible or even desirable for your situation so don't know how helpful it is! Here are some other things I considered before deciding on the shed:

If you go with the filter box in the link above, you can probably hide it pretty well with plants as it will be set in the ground at the same level as the pond. Leave yourself a way to access it, perhaps from the back, but plant around on all the other sides so that you only see plants from your primary viewing angles. You could also get a fake stone to cover it to keep out debris.

I've also seen people hide their filters by building a little wooden dock right over them. You'd want a hinged door on the dock so you can access the filter for cleaning. This not only hides your filter, but also gives you a nice spot to plunk down and watch/feed the fish.

As you indicated above, a drain might be a good idea if you have a lower point in your yard to run a line to. (The sludge is great fertilizer for plants - so when you open up the line, collect it in a bucket.) If that's not an option, you'd probably have to vacuum it out periodically.

I'll try to find more pictures of hidden filters...

This message was edited May 4, 2008 1:53 PM

Those are great photos...it helps so much to actually see it all. I remember that you had posted a photo of your absolutely fabulous shed that you built, but I thought all the workings were in the shed itself...I love that you were able to put it below! I think that shed is the best!

Yes, it does make sense about the water level now...I just never gave that enough thought to think about how the water would try and stay level between the pond and the filters...a key for proper placement, for sure. So, the exit piping for the filters should be at the level I would wish for the water level in the pond...correct?

That you have two filter barrels...is one for the skimmer and one for the bottom drain, or did you say that you have two bottom drains?

Yes, I also could see the photo quite well where you dug the initial trench for the plumbing for the bottom drain...before the shed was built over the filters, etc. That was very helpful, as well.

Also, with the filters, do they keep your water clarity high? I don't think I remember you mentioning that you have UV lights or anything additional? All the photos I have seen of your ponds and waterfalls, they were stunning and so natural-looking, Songs. Before, I never needed a UV before when I had a smaller ponds in series. (My biological filter that was a lily pot with the submersible pump in it, surrounded by old plastic curlers for the bio-media and covered over with filter mat...I never needed anything more and my water was crystal clear-but it was much smaller in scale....) I am guessing from your photos that the filters alone are working well for you.

As they say, "a picture is worth a thousand words." It is so very helpful to see your system in photos. I cannot tell you how appreciative I am that you took the time to take them and then to post your photos on for me and anyone else considering this in their pond construction.

What a great job! THANK YOU!

Interesting discussion.

I'm currently having bottom drain problems. Don't quite know why but the pump working it has pretty much given up and another isn't doing much better. My sequence 7800 is in to be looked at and in the meantime I'm using a 6800. A more powerful Sequel Showa is on the way. Basically I think the problem is some blockage in the pipes somewhere and in addition the original pond was built with 2" pipe over a long distance which was then modified on the outside with 3" pipe but the (2) 2" drains remained as they were under the concrete floor. These drains feed into another 2" and there is where I think my problem is. I can assume some small rocks or other debrit got into the pipes and it doesn't take much to clog the various bends or corners. To my mind there can be no other reason for the pumps not doing what they used to do. The new Showa will be proof of the pudding. It arrives Wednesday and is supposed to give me 3200 gph even at 20' head.

Anyway, this is a stopgap as I want this pond right even if it kills me. My plan is to buy one or two stock tanks, some filters and airpumps and then figure out how to get my koi into them. I was going to buy 150 gal rubbermaid tanks but now I just saw a nice blue fairly portable tank (see http://www.aquaticpondsupplies.com/ShowVatsTanks.htm )
Got to figure out how to get in and out of there though.

I will then have the floor torn up, inspect the pipe for blockage (to satisfy my curiosity) and then install a proper set of 4 inch drains with the appropriate piping. It will be a mess as they will probably have to go under or through the concrete walls too. It's just stuff you find out after some 'expert' builds you a pond for 20 grand. My present bottom drains are like from a pool or something and the little holes fill up with algae. One even came off completely and I suspect some rocks were sucked in. I have another Sequence 7800 which works the water fall and it runs like a champ but the feed is from a 4" pipe cut with slits and drilled with holes to provide adequate water input.

My last effort will be to change the skimmer but I will wait to see what effect the new piping will have as it's on the same pump.

Will report later on what's happening.

Fred

Oh my. Get a big net, have someone hold a spot light and try to net the fish at night. They don't notice the net quite as quickly when it's dark. That was one way I could catch mine. I had to sneak up on them. Loweriing the water level also helps, of course, because it gives them less room to escape your clutches. The alternative is to use a sein net. I've done that too. We dragged it across the pond like a curtain to herd them into a confined area, then went to work with a scoop net. Best wishes. I'm sure you'll get this problem identified and permanently corrected.

I'm not sure whether you're referring to the bottom drain to filter lines or the pump to biofilter line? But either way, it is not necessary to have the lines be at level with the pond. The filters will fill to the same height as the pond regardless of where the pipes come in or go out. That being said, I'd follow the picture for pipe placement. What is more important, is that you decide where you want your pond level to be at and place your filter so that it will not overflow at that level. I would make it so that the top of the filter is two inches or so higher than your pond level, that way it can handle some overflow if it rains.

I have two bottom drains - one to each filter and then the skimmer is also plumbed to one of the filters. So one of the barrels has two lines going in and the other only one. You probably don't need more than one filter, but I'd keep both bottom drains on their own lines all the way into the filter (i.e., do not join them before they enter the filter). And don't forget the valves or you'll never be able to empty that filter for cleaning. (I used ball valves - I seem to recall being told it was the better choice for the bottom drain lines in my situation, but you could also use knife valves (or gate valve - same thing) as I see the picture has you doing. Ball valves are more expensive and the 3inch and 4 inch are hard to turn, but they are airtight - whereas knife/gate valves are not as much.)

My water clarity is very, very good. I think it's a combination of the biological filter (150 gallon stock tank with filter media) and the bottom drains/mechanical filters. I do not have a UV light. My pond also does not get a lot of full sun, so I seldom have the algae problems that plague most ponds. One product I strongly recommend is barley straw. I am absolutely amazed at how well this stuff works and it's completely natural. This spring when I started up my pond, it was a little murky and brown and smelly. Within 24 hours of putting the barley straw in, I saw a noticeable improvement. Within a week, my pond was as clear as water can possibly be. I have had these same results every spring when I add the barley straw so I know it does work. I replace it two or three times throughout the season and my pond stays clear.

Tell me about your plans - how many gallons will you have? What is your biological filter? Will you have a waterfall? Full sun?

Fred - have you tried blowing out the bottom drain lines with an air pump (or even leaf blower)? That might help get your lines cleared until you begin your renovations. I agree - you need the 4 inch lines for the size pond you've got. I would be so annoyed at those "professionals" who built your pond. I've been following your threads since you began - it sounds like they made a lot of costly (for you) mistakes.

Fredrump,
I've also used childrens swimming pools (the 8 foot popups) to move koi in to for temporary housing. They are extremely inexpensive (at places like WalMart) and come in any size. They're cheap enough to throw away when you're done if you don't have storage space, and large enough to run small filter and pumps in while your working on other things.

I've thought and thought about how to pressure clean the underground pipes. I even thought, maybe I can get the fire company to come in and blow them out. :-) In the end the problem will remain though. My piping is simply too small for the distances involved.

If I could give any advice to anybody it would be to go bigger with the pipe. It doesn't cost that much to have one size larger but it will give you double the water volume. What's in the ground stays in the ground and it needs to be done right the first time.

As to catching my fish, I was wondering if anybody has used these tube like nets? The fish can swim in as they see an opening at the other end but once they're in they get shut by the net holder. The purpose of these nets is to prevent damage to the fish, especially the butterflies. Mine are also pretty big and heavy.

I will go with the night time catch and lower the water. What do I do about the plants. My planters weigh a ton. How long do water lilies and lotuses live outside the water? Will sandbags actually hold water? Maybe I can make a little sub pond in my shallower area to put the plants in? I can fill it with well water and set the plants in there. I even hate the tought of all this.

Fred

Fred you have done so much hard work with this pond and now it looks like more. I have to tell you though that it is going to be worth the effort. Your pond has always been beautiful! Can I make a request that you post pics before, after and during for those of us who really would like to make a system like this but need good visuals?? If I put on my sad puppy eyes and say pleeeeze??

SongsofJoy:
Thanks again for further clarification for me. When you had mentioned that the level of filter was important to the pond water level, I wanted to verify the desirable level. So, a few inches over the desired water level...that helps me. For comparison, how many gallons is yours?

Mine will be approx 15 by 20 ft. It will be 3-4ft deep. It may grow in dimension, as I just have the rough hole that size, courtesy of the neighbors mini-front-loader. I need to chisel out a ledge for the rock side walls and for foundations for larger rocks and may dig further out for a shallower area yet. It will have a waterfall too. I did buy a biowaterfall box and a skimmer (both have biological filters). I may place a small pond above the waterfall, which would help as a vegetative filter. I did not get the pump yet, as I want to figure this last in case it grows further and after I have a better idea of the heighth it must pump. As it is now, it is 5500 to 7200 gallons. The oval shape makes me think that two bottom drains would be better. I guess over filtration would be better than under.

Do you recommend any particular pump, through your experience or of others?

I really appreciate this, as I want to do it the best way I can before liners and pumps and drains are ordered. Mistakes could be costly in time and money. And the final outcome of the clarity and ease of maintenance is the goal.. plus.happy fish and happy owner...

Hmm, I guess my previous message was lost in space.

I always take pictures of everything to have records and approx locations in the future.
In the below pic you can see the offending 2" drain pipes and the stupid drain cover. Maybe they would work in a pool but not a pond which has a tendency to accumulate crap on the bottom plus the Koi seem to be able to bring rocks over there out of the pots. Don't ask me how.

Fred
PS I'm going get a kiddy pool at Kmart for the plants and the portable koi pond for the fish. I may need something like that anyway if I ever add a new fish as a quarantine tank.

I have a large pond with 4 bottom drains. I bought almost all my equipment from macarthur water gardens, and they were very helpful in the planning stage. The link:http://www.macarthurwatergardens.com/
We also built a shed to hide the filtration equipment, but it is located inside. I have 2 1/3 and 1 1/4 horse pumps and a medusa filter. I use hydrogen peroxide to control algae - found that on a thread here. The only thing I would have done differently, and will be doing this year, is adding a large air pump for the winter. I lost all my koi and the thought is that they somehow lacked oxygen - either from decaying leaves or a turning of the water.
Here's the shed:

Yes, Fred, please do post photos and anything to help us in the midst of a large project! I am so sad that you are going through all of this, esp when professionals were paid to give you the best results upfront...four inch pipe it will be! You truly have a work of art with your pond.

Since I was used to working with a much smaller garden pond prior, even then it was a challenge to capture all the wildlife. Luckily, my son and all his teen friends that love fish, frogs, snails,etc were most happy to help. Even with a small pond, I also would drop the water level as low as possible without causing harm to the fish to aid in catching them.

I am sure you have a lot of plants and large ones, at that. When I would clean out mine, I used large Rubbermaid bins and baby pools (as you are planning to do...) to hold my plants. I also kept them in the shade during the time they were out. When the fish were in the holding tank, I used some StressCoat in the water to help in case the fish were bumped in the move.

Keep us up to date on your project. If it were me, I would have a hard time with my feelings towards those that I trusted to give me a better mechanical result for what I paid for. (But the photo that you just posted is absolutely beautiful, Fred!) I know I am learning so much from everyone, esp SongsofJoy and others on DG, to ensure the best outcome, although there WILL be SOMETHING I am sure I will say I wish I too did differently. I had had my previous water garden setup for years, but just by going larger my learning needs grew larger too. We are learning, but at least we have each other to share our knowledge with...for that I am grateful. Let us know how you are doing.

Dbsmith, What a great pond you have! Your pond shed is very neat, too. Did you design yours? I love it! Thank you for the additional site to look too for info and supplies, too.

I am going to have to come up with a platform or something to hide my workings, I guess. I have plans for a potting shed/storage shed already in our yard, and two may be too much for the space. Goodness knows, I need storage and an area to store my tools. I would love to be able to park in our garage again! I wish I had the slope to work with that Songs has...that would solve everything!

I will keep Mc Arthur in mind as they are in FL now.

Looking through my pictures, I seem to have missed a moment when they put in the bottom drains. One moment I had steel rods, the next two pipes stuck up out of the ground. I suspect they ran a 90 at one end and a T for the other with one 2" pipe connecting both. Or maybe not. The picture shows sort of a trench towards the far and of the photo. The skimmer is over there on the left and they must have tied the bottom drain to that line. This opens up a whole new picture for me as digging over there is not as problematic as digging yo my driveway on the (near) other side.

A concrete saw should go right through that stuff.

What about if I do two separate 3" drains out from under the pond? They would still come together somehow into one 3" anyway but I could build a valve box of some kind to shut one or the other off. What do you guys think?

I'm thinking a 4 incher will be tough to bend and work with and the suction is on a 3" pipe anyway. Or I could buy two 4" drains each with an air pipe and each running into a reducer and 3" with valves on the other side of the wall.

Here is what I saw after the fact.

Fred

From what I have been learning about the bottom drains, the installation instructions have been recommending two 45 degree connectors instead of a 90...the sharp bends are advised to avoid. If you have a 90 plus a T...could this also be working against you? Again, I am not speaking from experience, only from my learning before I do it. Is there a way in reconstruction, if this is indeed the case, if you wish to change this too?

I do not know about the effect of the reducer...

Now how did that picture turn itself sideways? Before I correct that I found something else I want to change and maybe I should do it right away. This skimmer is a pool skimmer and not at all what I see on pond sites. It's basically just a strain bucket but being that there is not enough suction because of the distance involved, it doesn't do much skimming either. I used to find fish in there when they were small and now I have some pleckos which like it in the bucket. They seem to be none worse for the trip but I would like a real pond skimmer on a separate pump and filter setup. I just don't know where to put the pump & filter. All the pumps and filters are far away from this point. I need to think some more on this.

BDiggiging

Yes the current setup is bad as it has the 90 and the T and the small pipe. That's what I ant to change. My point was that dealing with a 4" pipe and two drains can be hard to do unless the whole pond is open. I'm hoping to just dig a trench and not break the entire pond. In addition, I would pefer to have two pipes on two drains joining only outside the pond. Having two 4" pipes may be a bit of overkill which is why I thought two separate 3" should do the trick.

Here the picture I spoke of turned correctly I hope.

Can someone explain to me why I have an opening on the skimmer in the wall for a pipe? Doesn't the skimmer work strictly through the main skimmer opening and away to a pump and filter on the inside? Am I making sense? Look at the pictures above.

RatherB, I always figured my pond is about 3000 gallons, but I've never really tried to get an accurate measurement. The larger pond is about 16 x 20, but only about 2.5 feet deep. The smaller pond is about 9x6 and same depth. The two ponds are connected by a narrow channel over which I have a bridge. Then I have three small pools in my stream where the waterfalls are, so I think I have another 500+ gallons in the stream.

As for pump recommendations, I can only tell you my experience with the two I've had. My first was a submersible. It was an energy hog. After much research and consulting with a professional pond builder, I settled on the Performance Pro Artesian 1/3-56 external pump, 5600 gph. I am very happy with it. It pumps more GPH than my submersible for less than half the cost per month. I don't know a whole lot about submersibles - I'm sure there are good ones out there that don't cost as much to run, but from what I understand, submersible pumps do not last nearly as long as an external will, so you'll need to replace it every few years.

I would definitely go with the two bottom drains for your size pond. As for 3-inch versus 4-inch....I have not regretted going with the 3-inch (yet). They have never clogged, but I don't rely on them alone to clean the pond bottom of leaves and large debris. Every fall and spring, I scoop out any leaves that settled with a net instead of letting them go through the bottom drains. That being said, it might be better to just go for the recommended 4-inch and then there's no room for possible regret later!

Fred - I could be wrong, but I think the extra skimmer hole is for an overflow line, if desired.

I am going to try to find the thread on "the other site" where I got all my help on bottom drains. There is a lot of useful information on the impact of choosing the proper size of bottom drains, the effect of adding a reducer, etc. I tried searching for it the other day, but couldn't find it. I'll try again though...

Thank you so much, Songs. With electric rates expected to climb with deregulation in PA, that is an important aspect to evaluate, too-the cost of running the pump. I will certainly check out your pump. My submersible pump had a stainless steel housing and it has lasted for over 5 years or more and is still running. I am sure I couldn't get that lucky again! I just need to get creative on thinking up a unique idea on how to house/hide my pump and filter. I just absolutely love what you have done with your pump, the setup and how you have hidden the workings. But thanks to you and the others that have contributed to my thread, I have a much clearer sense of the bottom drain as well as how the flow should be around the loop. But I think my upper pond will most likely be added on next year, as the lower major one will use all my energy for a year! Really, you should be extremely proud of your pond and set up. It is truly impressive.

Fred, I wish your reconstruction the best. When you get things done, you will be so much happier, I think. I hear the frustrations, but it is like building a house...even though you plan so carefully, when you are done and living in it, there is ALWAYS somethings you wished you would have done differently.