Building a Koi Pond

[kajr]

Just wondering if anybody has experience of building a pond overseas in a country with a hot climate. My own pond in the UK was built with 9" thick concrete blocks but where I am now intending to build they only have thin blocks, probabley 3" thick. That doesn't seem strong enough to me if building a pond 5 or 6 ft deep even if is all below ground level. I am assuming therefore that I would need to use some other method, shuttering and making a re-inforced concrete wall or building two walls with the thin blocks and infilling with concrete. If the latter how thick would the infill need to be and would it need to be re-inforced. My pond in the UK has rein fibres in the render for waterproofing. Could an infill be made to be waterproof therefore not needing a waterproof render?

Kevin

[Ian Stirling]

Depending on the soil conditions, might a simpler way be a 45 degree slope on the walls, and a butyl liner? This does imply a rather large pond, to get to the depth. My pond has walls of around 80 degrees, as the soil is very, very stable, and has worked fine.

[kajr]

I am not sure whether a butyl line is available where I am intending to go, Thailand and the pond is likely to be very big so cost might be a problem anyway. Labour costs on the other hand would be very cheap so a more complex construction would not be a problem.

Kevin

[The Natural Philosopher]

I'd just cast a concrete basin.

Ive seen aa swimming pool done this way.

Start with a deep pit, and cover base with crushable hardcore, then prop up some mesh and some vertical steel rids (or sloping if the sides are that way) and cast the base. Then shutter up and cast the sides. Its a bit easier if this is not done too much at a time, and lay in horizontal rods as you go to relieve stresss as well. Avoid 90 degree corners - these becomne stress points and may crack.

When all done, render over the inside for a fancy finish, or just leave it.

Add soil for water weeds, gravel for fun, water, and fish.

Probably might need a fountain or two to aerate it.

If its too much hassle, consult with local swimming pool firms, who will probably do this every day of the week,.

[Rick]

Hi Kevin, you could try laying the blocks on their side. I'm in the uk and that's what I've done with the normal 4inch blocks. See

other good resources are and Hope this helps. Rick

[Chris Bacon]

Without the appropriate finish, this is a good way to kill Koi carp.

[Steve Firth]

Which country?

In Italy for example the standard block is a terracotta block with lots of holes. Mostly useless for the work that you want to use it for. However, almost any type of block is available at the builder's merchants all one has to do is ask.

[BigWallop]

Dig a hole and put a liner of plastic sheet or canvas in it.

[Gizmo]

Oh look ... floating fish !

[The Natural Philosopher]

Not if its big enough and you run water through it long enough to leach out any residual surface chemicals.

[Mark Trueman]

Agree with this, you have to run water through it, depending on what cement you use, for up to 8 weeks. Standard grey portland cement leaches chemicals into the water that raise the ph. Once this raising of the ph effect has stopped, you would then be safe to put fish in. But this does take time. Using white cement (snowcrete) will reduce this curing time as it has a lower curing ph.

Ive got concrete structures in my marine tank, and im pretty sure that marine fish and inverts are much more sensitive to water conditions than a few big goldfish, and they are all happily swimming around