View Full Version : Extending KOI pond

04-20-2008, 10:50 AM
I've started extending an existing KOI pond. The original is 6' X 3.5'. I want to make it 20' X 10' with a waterfall and a stream. In the pictures I have the original one still in place until I dig to the proper depth for my KOI. The old well on the side will be a small seperate water feature. The external equipment will be in the root cellar on the right of the pond, power is already present. I want to make the natural grade of the land work for the fall and stream? May need help calculating pump capacity for that height and length.

Currently I just purchased the house and have my KOI in boarding. They will not fit in this pond as it is. I have 11 KOI ranging from 11" to 2 feet.
I built my first KOI pond 5 years ago in my old house (the last picture). I learned what I should have done and hope not to make the same mistakes again? Always looking for suggestions and comments so please fire away.

There have been post on a bog filter? This is new to me, is it worth it? I haven't decided on a filtration system yet, the last pond was a BOISTEP filter, a 40 watt UV, top and bottom skimmer with submersible pump driving it all. I need to step it up with this one because I worked :weightlifter: to keep that one clean and would like to enjoy this one.

04-20-2008, 10:54 AM
i use cat fish to keep mine clean and u are welcome to come get a few for your pond when finsihed

04-20-2008, 11:13 AM
Nice grotto.

04-20-2008, 05:21 PM
Dusty: Thanks I just may take you up on that. I never thought of putting catfish in. Will they winter over or do you take them out? My pond will be over 36" deep.

Firefly: Thanks. You know I had to look up grotto! lol Yeah I want to put nice lighting on it, maybe in it? Something to make it more welcoming than a dark pit in the hillside.

Update: I have the depth I want it to be, but because there are small koi and three frogs from the previous owner, I am reluctant to just rip the old pond down. I have to get a tank to place them in first.

The left side top is the stream part that I had to clear out of the way of some brush.

Question: Should I do a concrete footing near the brick patio?

04-21-2008, 03:02 PM
it wouldnt hurt to do the concrete footing near the patio,.
as for filtration, i like bottom drains and external pumps as well as a bead filter of some sort.
you could very easily incorporate a bog filter into the upper stream area, and this would only help to clarify your pond. a bog filter will remove alot of the nutrients as well as small particles that would pass through the bead filter.
If you can set up an area with a gravity fed settling chamber before your pump. This too will help remove a large amount of waste as many particles of debris.
With those things i mentioned you will be able to enjoy your fish and cocktailS much more than you will be doing maintenance.

04-23-2008, 02:22 PM
Thanks n2. I think I will look into that bog, As for the gravity fed chamber before the pump, I'm not sure what you mean? You mean like a settling tank before it goes to the bog?

Here's more pictures of the progress. Instead of extending I guess I demolished!? I have the small koi in the holding tanks with filters running to keep it clean. The frogs have the adjoining tank to keep them company.

I started the measurements and have come up with 16' X 14'. I would like to do different levels and plant shelves in it. (The last pond I did I forgot to and the thing was like a four foot pit in the Earth and I had to add milk crates to the bottom to get the plants at the right height.)

Back to digging and I need to lay down that concrete footing today so it's ready for the wall and liner this weekend. I'm racing the clock because I don't feel like paying another month boarding fee on my KOI.

04-23-2008, 02:24 PM
a settling chamber before it goes to your external pump. this will remove large debris and prevent is from clogging your pump basket and getting into the bead filter,,, if you use one,.

04-24-2008, 11:17 PM
my pond in only 22 inches deep with the rock in it only the top 4 inches have frozen so all is well

04-26-2008, 11:46 PM
Thanks n2, I will take the advice and do the bog filter and the settling chamber before the pump. Anything to make it work and not me.

Dusty, Thanks again for the offer.

I am still digging away. I really haven't made up my mind as to what the end result should be?

I'll keep posting my progress and if anyone has any suggestions let me know.

04-28-2008, 07:29 PM
A bog filter is a fantasic option very low maintenance and exceptional filtration. stay away from uv stuff. you should have at least a 4500gph pump in this size pond...
Trailsend Water Gardens, LLC

05-06-2008, 04:55 PM
the rest?...

05-17-2008, 12:35 PM
Well between Rain and work I've had very little time to devote to the pond, but for the first time in weeks... no rain on Saturday and no work. Last night I placed some rocks and mortar to get a head start today. I have to run out to Lowes or Home Depot and pick up some more mortar, but after todays work I should have some pictures for you.
I priced out some of the equipment I want for the pond and would like some feedback if I'm being taken? I went to the same place that is boarding my KOI...
Oh and get this, he tells me one of them died, like an 18" one and there was nothing he could do about it, but he'll work with me on replacing it! That's nice of him...

So here's the prices he gave me:
UTIMA 11 4000 2" - 1484.00
80 Watt UV Sterilizer - 804.00
22" Spillway Box - 299.00
and various other unions, bottom drain, etc. - 200.00

05-18-2008, 12:54 PM
I like the cave in the background

05-18-2008, 05:16 PM
good equipment,,,thats what i would use.,,, except the spilll way deal.

06-08-2008, 11:57 AM
Well it's been a rough start, but things are looking up. I have completed 98% of the retaining wall for the pond. I will dig a little more today and set up the plant shelves. I haven't purchased the equipment yet, thanks N2h20 for input.

I think I will look else where for the spillway OR the guy that is boarding my KOI said one of them died unexpectedly?! An 20" Bekko! Doesn't sound right to me, as I saw it one week earlier and it was fine and no other fish in the tank is distressed at all?! That aside the guy told me he would work with me on something, so I told him I'm building a new pond and maybe we can work out a deal that way?
Still, I have to admit, that KOI could have brought in a nice penny?

So back out to digging and one more step closer to finishing!

06-22-2008, 09:20 PM
Liner is down. Filter is assembled. I had a question about the seam... I forgot to purchase the double sided tape and the rubber cement? Is it okay to use rubber glue that you can get at Home Depot or Lowe's?
I have to arrange the rocks better. Doing it by myself, so it is taking longer than expected.
Purchased Equipment:
21X25 Liner.
21X25 Underliner
Pondbuilder 13" skimmer.
14" Pondbuilder Cascade.
Tetra Bottom Drain.
Aqua UV 80watt.
1/3 hp Pro Artesian pump.
Ultima II 4000 Filter.
Total with all the elbows and unions= 3,600