Hi All,<br /><br />I have had a basic pond with gold fish in for a few years now, but it has been netted and not filtered. I have decided to embark upon a big project for me and to try to make it a lot bigger and more heron proof if that is possible. Hopefully also to keep a few more different fish like commons and mirror carp etc. The size should end up about 10000 litres but the hole is not dug yet so best layed plans and all that !&nbsp; I am planning to put a concreate base in then block up the sides with a cavity to be filled with concrete, then brick on top to a height of about 18 inches above ground. After that I am not sure about water proofing etc. I hope to be able to pick a few brains along the way so here goes with the string of questions, probably not in the right order but.<br /><br />Why does every one tend to recommend a drain in the bottom ?<br />What type of pump and filter arrangement have you all got and does it work?<br /><br /><br />There are a lot more questions to come but please comment on my initial plans if they look flawed.<br /><br />cheers stew<br />

If the pond is cuboid your main liner options are sheet liner, flat sheet or boxed, glassfibre, paint, or naked concrete, of these I would look at sheet liner or glassfibre?
If the walls are seriously curved and you want a really neat liner you may be ruling out sheet liner.
Where are you? If around yorkshire have a look on yorkshoire koi for, I think, Matt William, he is a glasser with seemingly a good reputation.
A bottom drain is used for ease of maintainence, the sediment falls to the bottom and is funneled, by a correctly shaped floor, into the bottiom drain, BD. A gravity driven flow flushes the sediment through to the filtration where the sediment is removed and the water is pumped back to the pond by whatever means you choose, if you go for the complicated filtration options, eg bead filters some of these may be after the pump
"Gravity driven" refers to the fact the the pump is after the filtration, the filtration is via tanks which are open to the air and the level in each successive tank is lower than that in the previous tank, thus the  water flows down hill. The advantage is that the sediment reaches the filtration in the biggest possible chunks which are more easily removed than if the sediment had been puried by passage through a pump.

Pumps, these can be submersible and placed in the last filter tank or externals connected via plumbing to the filter and the the return, as a general rule externals are more economic to run for a given flowrate but more expensive to buy then submersibles. What 'size' of pump depends on
1) what flowrate you want
2) the size of your plumbing
3) what filtration you have
4 ) how high you want to lift the water above the pond surface

Really these all relate to the pressure difference across the pump that you want or need to drive your desired system.

Note irrespective of what type of pump you choose you should have some for of filtration before the pump, be that a screen on a submersible or a proper filter, simply to stop sticks, stones and fish reaching the pump and fish should be able to out swim the current through that filtration, ie dont put it at the downstream end of a pipe carrying a flow so strong that a fish etc cant swim out of the pipe.

Heron protection, I use a electric fence around the top of the wall of my fish pond. Its from Drivall near Birmingham, the posts are 10mm diameter GF and set in metal sleeved holes in the wall so that they should be easily removable. However the only close fitting pipe I found to make the sleeves seems to contain iron which rusts and jams the post. I am experimemting with other options for the sleeve, the next will be plastic sleeves cut fron the old style fairy liquid bottles but you maybe able to get 10mm copper gas pipe which may be a close fit, it is no longer used here so I cant get it.

Hi ,

Thanks for the replies, lots of food for thought sean.  We started digging Sun in that 30 degree.  Bad day really but had some help so we tried.  Unfortunately the ground is almost mixed ballast , clay and rock mixed in. After much sweat and tears we only managed to get down about 18 inches! and had to give up. I am now trying to source a small digger that will get down the side of my house. 

I had a look at your pics hectorsgaf ( thanks for the welcome ) they look great. Not sure of the species in the pond at the end though !!!!  What type of filter have you got there ,is that an off the shelf job ?

cheers stew

Hi Hectorsgaf,

The filter is certainly keeping you and your fish happy.  What part of the country is your dealer?  I am interested to see if its near me !!!

cheers stew

Thats a shame,  a bit too far from me.  I will have to do a bit more research locally when i eventually get my hole a bit deeper !  My youngest daughter is on honeymoon now so pond project can resume shortly.

cheers stew

I got my filter that was advertised on yorkshirekoi, had to act quick tho they go quite quickly, i looked for about 2 weeks a couple of times a day.
I got a courier to pick mine up as it was too far away.That cost £55, but its still cheaper than paying full price.

keep going stew, reckon you must be almost halfway there ;D ;D

We had a raised rockery and water fall feature with the small pond but the other half quite likes the idea of a more '' less cluttered '' garden and house for that matter !!! So two skips and a digger are comming on sat next week. Fingers crossed and some moderate weather and a bit of luck to what is down there we sould be on our way.

cheers stew

Hi,  the hole has finally been dug !

here are a few update pics

cheers stew

hi,
the deepest level is about 4 feet and the shelf is about 2 feet deep, this should give me a finished depth of about 4 feet 6 inches when the raised wall is done and a shelf of 2 feet 6 inches. 
Do you think I may get away with concreating it all in one go. What do you think ?

cheers stew