Backyard pond

[avorancher]

Digging a 10' x 15' x 6' deep hole into granite bedrock and need to smooth up the sides so I can use it for a koi pond. The sides are jagged where the jackhammer would break off chucks as I dug. I was going to use a stucco base coat but I think the gaps are too large even if I use a wire mesh. Any ideas on how I could get the sides smooth?

Ultimately I want a bowl shaped bottom with the sides nearly vertical. Once I have the sides smooth, I plan on sealing it with fiberglass cloth or a polyurea coating, so this smoothing coat doesn't have to be waterproof.

 

[EddieWalker]

Have you considered a rubber liner? When I did one, I found a liner online for a good price and also a felt underlayment. The underlayment will protect the rubber and you wont have to worry about doing very much to the hole you already have. You might want to add sand to the bottom and inside edges, but that would be about it. Keep it simple. hahahahha

Eddie

 

[dirtworksequip]

Depending on what you want to spend. I'd have someone come in a shot- crete it. You could put in any ledges or waterfalls with the shot-crete and have a finished pond and not have the time and expense of fiberglassing it.

 

[avorancher]

Eddie, The rubber liner idea would work, but I don't want all the folds that a free form shape would require.

Shot-crete is expensive here in S. Cal, (about $15+/sq. ft.) plus I want to be able to do it myself if possible. Gunnite or Shot-crete would still have to be sealed to prevent leeching into the water and affecting PH. Access for a pumper is also a problem.

I'm wondering if I could pour concrete in small (maybe 12") lifts using flexible board forms. Small lifts would allow me to push the concrete back into the crevices yet keep the walls thin. I would have to find a way to hold up the forms. I'm not sure if the cold joints would be a problem since I'll be sealing it anyway. Many people use concrete block which would also be cold joints. The walls are rock, so I really don't need shear strength... just compressive strength to withstand the weight of 8000 gal. of water.

 

[EddieWalker]

I don't think you'd see the folds. The liner is black and it sort of all blends together. Especially when the alge starts to grow. hahahaha

I know a guy who did his pond in concrete. It was very labor intensive, but it didn't leak and turned out pretty nice. He didn't have to do the ring of rocks to hide the liner routine.

How clean can you get the rocks? It might be a silly idea, but can you seal the cracks with silicone or caulk, and then paint over them with a waterproof paint? Kind of like a basement waterproofing paint? Will roofing tar work?

I read that ther are materials that are toxic for fish that you are not supposed to use to seal a pond that are allot cheaper than the aproved materials. But if you don't put fish in there right away, the toxic level of the water will drop to a safe level over time. Differen products take differnet lengths of time, but almost everything will work if your not in a rush.

Eddie

 

[Paddy]

Avorancher,

I have built a few water gardens over the years. Some fancy poured concrete multi levels pools falling into each other. Sky is the limit. I think you have two options, roof rubber, $.5 sq-ft over treated wood or pouring concrete. Liners, Roof rubber being the best price, puncture easy if it gets between rock. I have framed walls of treated 2x4 and 1/2 treated plywood. Rubber then sits/folds real nice as pleated corners. The top ledge can be made perfectly level, (because you know the water will be!!). In the one I built for a friend, he wanted flag stones as the surface surounding the pond. The wall was framed such that the top of the wall was sitting below the ground level by the thickness of the flag stone. The rubber came up the framed wall and was stapled to the top of the wall. The flag stones hung over by about 3-4". We back filled the void between the framed wall and the dug earth with plain dirt.

Eddy is correct, after a very short time, the rubber won't be seen again untill you broom it off.

Basic construction of ponds is very easy. Where most folks have troubles is placing stones to look good. The ring of stones around the pond is a clasic mistake. You did not mention if you were going for a kidney shape or a formal retangular. Formal/Rectangular with flag stones is easier because you are not tring to copy nature!

Buy the smallest Koi you can. They grow very fast. Goldfish on the other hand grow very slow. I have some that are 15 years old and are 6" max. I bought 4-6" Koi a few years back that are 2 feet long

lGood luck.

 

[avorancher]

The bottom will have two 4" drains, plus there will be 6 return jets near the bottom to keep the bottom currents in a circular motion, and a waterfall and skimmer. I'll be circulating 7,000 gallons through the filters every hour.

The first photo shows an overview. The pond itself will have an 18" stone wall (like in photo 2) around its edge to keep leaves and groundwater from entering the pond. The water level will be 10" above ground. A foot bridge will cross about where the 4x12 is now laying.

The 2nd photo shows the 30" x 100' curved stone wall I'm building around the "stream" that goes from the filters to the pond (had to do something with all that rock). Water will flow along a 35 ft. stream and spill into the pond through an opening/waterfall. The trench goes back to the filter pit and will be filled in after the pipes are laid.

 

[Timber]

Nice project, good to see you using 2 bottom drains. Never use roofing material as it will contaminate the water and it is not fish safe at all. You can use pond liners and a lot of people use pond tape over the folds. Personally you never see them so I don't worry about it. I would not use fiberglass at all

 

[flusher]

Digging a 10' x 15' x 6' deep hole into granite bedrock and need to smooth up the sides so I can use it for a koi pond. The sides are jagged where the jackhammer would break off chucks as I dug. I was going to use a stucco base coat but I think the gaps are too large even if I use a wire mesh. Any ideas on how I could get the sides smooth?

Ultimately I want a bowl shaped bottom with the sides nearly vertical. Once I have the sides smooth, I plan on sealing it with fiberglass cloth or a polyurea coating, so this smoothing coat doesn't have to be waterproof.

Wouldn't used concrete to fill the crevices. I'd use parging consisting mortar mix with the minimum amount of water to make it thick and sticky. That's how I attached the stone facing to my concrete block barbecue pit last summer. Then use the rubber liner. The weight of the water will keep the mortar from moving any.

I'm planning to start construction on a 5'x10'x5' deep formal-type koi pond in March 07. I only have gravely soil to contend with so I'll dig a 2' deep hole 3'x8' and leave a 1' ledge around the perimeter. Then I'll build a 3' H concrete block wall and parge it with sticky mortar. Plan to use a rubber liner. May use the same facing as the barbecue pit or might spend the money on some type of cultured stone facing.

 

[Paddy]

Timber,

I have used roof rubber on many ponds. I have had an oudoor garden 12 years old and just took out an indoror pond. Both used rubber roof material. I'd rince them but that's about it. The only time I would have fish die is in the Summer if the pump was cloged. My fish grew fast and large. The rubber gets covered in alge and muck real fast. Only when I do my yearly cleaning do I even have a hint what's there.

I don't have any tech data to prove my case, but it sure worked well for me.