Expanding pond without removing fish--has anyone done this?

[kmarcel]

Hello, I'm new to this forum, but have had a pond for almost 20 years. Last year we had the liner replaced and had a new filter and pump installed. It's probably only a 900 gallon pond. I have 12-15 koi, a few of which are brown that were reproduced in the pond. My concern is the koi and size of the pond.

I have recently read online where some people have added an extension to their pond by digging the hole the size you want next to current pond, then lowering the water about 10" and sealing the 2 liners together where to two pond meet. That area would only be about 10" deep, enough for the fish to move back and forth. Worse case scenerio is if the liners leaked it would be in the area where the 2 ponds are joined and would not drop below the 10", keeping the fish safe.

I know I may have to put in a 2nd pump to get the area of where the new addition would be. My question is would a bubbler be sufficient as it would keep the water moving, or would I also need some filter in that area? The addition that I'm thinking about would only be about another 4-5' by 2' deep, maybe 300-400 gallons. My existing pond is 3' deep.

I'm really interested in doing this and wanted to communicate with people for ideas or suggestions, etc. I cannot re-do the whole pond by replacing current liner, since it's just brand new last year.

 

[sissy]

welcome and koi do get big and that is way to small for that amount of koi as they produce a lot of waste .My pond is 25x10 and just over 4 ft deep ,wanted deeper but I had to be able to get out after I put in the liner . :cheerful: I know of people who have done that and I did it for my new filter .I used concrete block under the liner and put new liner over old liner and extended new liner over it all by 2 feet and so far so good .Mine was done where if filter was to over flow it goes back into the pond .I really think so far it has worked so can't see why it would not work for you to put an addition on your pond .I know you will need it .My koi fish were a couple of inches long 9 years ago and are now over 2 feet long
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[sissy]

last pic is of my old liner and how far it came up and concrete block hold it up and in 3rd pic you can see on both sides the height of the pond and then see the 8 inch dip in the middle .It is at the bottom of the pic looking through the bridge and the opening is about 3 feet wide .I put bricks on top of the dip spaced apart from each other and then stones on top of the bricks .This is so the water goes under the stone not on top of the stones.I wanted the pretty stones to really show and not get covered in good muck

 

[HTH]

Unless you have space limitations I would make the addition larger.

 

[sissy]

I wish I could go bigger but this is all i can handle besides everything else I have to do .You could always go bigger and get new liner and use old liner for a nice big triple waterfall .But bigger liners are not cheap unless you can find a roofing contractor getting rid of some .That's how I found my liner 35 dollars and one new liner later

 

[kmarcel]

Sissy, thanks for the info. Did you do sealant and the tape for the liner to bond the two liners together? Was the concrete blocks the hard surface used to do this? That is my concern is sealing the two liners together without really having a hard surface to do that on. Maybe I could temporarily put some board under it. But then there are the curves to go up the on sides.

Howard, you're right I should go larger. I just want to keep area merged liner section only about 3 feet wide and about 10" deep so that I don't have a large area that is seamed together. Less chance for leaks if it's not such a large seam.

Any thoughts on if I would need a 2nd pump and filter?

 

[sissy]

I didn't seal between the liners and just hung it over since the water in the pond is lower .I had stock tanks to put my fish in but since I was just lifting the old liner up and over the block I just lowered the water in the pond and added the new liner over it and tried to get it done as fast as I could .I use 2 pumps ,if one goes out you have back up .I just found really nice low wattage pumps on pondfilter.com .But 1 I have is a harbor freight one

 

[sissy]

My water falls into the small plant pond and then into the bigger pond
[sharedmedia=core:attachments:57565]the water runs under the big rock in the center and ones on the side are higher up and water in the pond is below that level

 

[CountryEscape]

If I understand you correctly, Kmarcel, you want to add to the pond, to have more space for the fish, and will have a 10" area for them to swim from pond to pond, right? If so, you will definitely have to seal the liner. There are people on here who have done that with great success. I think you have a great idea to keep the seamed area not as deep as the rest of your pond. I would agree with HTH to go deeper on the new addition, if at all possible. That's a lot of koi, and they need deeper water than 3' if at all possible. Also, you are in NY, where you get freezing temps, so assume you use a heater in the winter on your existing part? If not, that 10" deep part may freeze solid in really cold winters, so you may want some type of bubbler available in the addition.
As far as if you will need a second pump, that depends on your water flow. If you have water flowing from one end to the other, and then back, you might get away with one pump. Not sure how your existing pump is set up, though. Keep in mind, koi need to have lots of water movement and flow, and clean water, so you need to be able to filter ALL the water. I guess in my mind if you have, say, a waterfall on one end of your existing pond, and you are going to add the addition to the far end, then you will have flow to the other side, but if you have a submersible pump in the existing pond, you should move it to the addition, to pull water from there back to your filtration system. Hope that makes sense. If you don't have a skimmer, that could be another way to get water flowing in the addition. You could put a pump inside of the skimmer (some types go on a shelf IN the pond, so no cutting of the liner needed) on the far end of the addition, then pump the water to a small waterfall feature or just put it back into the pond.
The main thing I see is the depth of your existing pond and your thought of going shallower rather than deeper on the addition. If you ask any koi keeper, going bigger is what they always wish they had done. So, if you are going to add water volume, go as big as you can afford, or have room for, in my opinion. Good luck! Post some pics and have fun!
BTW, I have 4 koi babies from last year (this is my 3rd year with my pond) and there are all pretty. Guess I got lucky! :blueflower:

 

[sissy]

just remember don't go so big that you can't handle it as that can be frustrating also .

 

[kmarcel]

Yes CountryEscape, my plan is to add more space for fish with a 10” area for them to swim pond to pond. When all is done it will have the look on one large pond. I know I definitely need to seal, tape, seal and seal, etc. The area that I plan to seal would be no more than 3 feet including the curve up the sides. That way there would be less area to worry about leaking. Unfortunately, due to the location of my pond I can only go in one direction for the expanded area. My pond has a patio on one side, deck on another and stream with small upper pond on the 3rd side. So that leaves the expansion to go out into my yard. It will go from a somewhat kidney shape to more of a horseshoe look, kind of a curve where the expanded area will go. So I know I’ll end up needing another pump and filter. Currently I have a skimmer with pump located at the end, but I don’t think the water in the expanded area will get movement or filtration from the current location of the skimmer, which I don’t want to move. It then becomes more of a project in doing that.

The sealing part is what worries me the most, especially since I’m going to be doing it in place without a hard surface underneath to make sure it get a good bond. I may be able to temporarily put some type of board under the liner so I have a hard surface, but the curves going up the sides might be tricky. If anyone out there has done this, please share any tips with me.

 

[CountryEscape]

OK, I think you're thinking you have to seal and tape your liner as it will be once you dig the addition. I would think you could attach the new liner to what you have over the edge where it is now, just place something like the board you suggested underneath the to-be sealed area. You will need something firm to press the two liners together and to keep it flat and still for however long it takes to seal it together well. Remember, if you had a really long liner, it would have to be folded over for the dug out area, too. THEN, dig the new part and run the liner up, over, and back down to the new pond addition. Does that help? I've never sealed two liners together, but lots of ponders have done that with great success. Just make sure you prepare the two sides well, and give it the recommended time to dry, and you should be good to go!

 

[addy1]

My best success has been from using pl roofing goop.



I then tape the edges together. I have also put double side tape, goop, double side tape and then tape the liner edges together. Clean the liner very good, I usually use some acetone, wipe it down. My liner has a rough surface, the epdm is smooth, the few times I have used epdm and sealed it I have roughed up the liner with some sand paper.

If there are any wrinkles that is where you will have the sealing issues. The goop has saved me when I have wrinkles.

 

[kmarcel]

Addy1 and CountryEscape, thanks for the information on what to get and the tips for doing it. If I'm following both of your instructions I think I would overlap the two liners with maybe at least a 6" overlap and then tape in both places where the liners meet? And then seal the same area where I taped? I had read another person's instructions who had also cut a extra piece at least 6" wide and taped that over the area where the seams were sealed for a little extra reinforcement. It's hard to read instructions and fully understand. Maybe I can find someone who has done this on youtube.

CountryEscape, I've re-read your last post and not sure I completely understand what you mean. What I think I would do in chronological order would be to dig the new expansion next to my exisiting pond. Then get the liner in place, lower the water in current pond to be below the 10" where I will have to dig down for the "bridge" to connect and then overlap the new liner onto the existitng (or visa versa, not sure it makes a difference) then clean the two liners really well with acetone or alcohol and then tape the seams, seal and do as much as possible to reinforce, allow however long needed to dry and then fill up the pond, and pray.

Please let me know if I'm going about this wrong or missing any important steps.

 

[addy1]

I would put goop in between the two liners, before you tape, also let it dry some before you tape the seams, which will cut down the air flow. Then tape the edge. I have done what you mention above, cut a piece of liner to cover a hole (my back hoe make in the stock tank) I cleaned the hole, covered it with pl roofing goop inside and out, put liner over the hole inside and out after a day or so, using more goop. Also gooped on a extra piece of liner to cover the seam. I like to double triple do so it works. Prob over kill, but never a leak yet, from a seam or a hole.