Deepening an existing pond

Art

Joined
Jun 18, 2018
Messages
3
Reaction score
1
Country
United Kingdom
I have a small pond and it was built some 15 years ago. It has a mixture of goldfish and koi in it that were all purchased when it was built. The fish have now become large but unfortunately I can't make a bigger pond due to lack of space so I wondered about extending the depth by building a higher wall around it.
The liner is a heavy butyl rubber version that is held in place by a wall at one end and slabs around the other three sides.
Obviously a new liner is needed but do I lay one over the existing one? Join Butyl to the existing one to extend it or what would you suggest?
I don't want to spend a fortune in doing it and I haven't got anywhere to move the fish to while its done. The good thing is that my existing filter box and pump will easily cope with a larger volume of water. 2018-06-18 14.57.34.jpg
 
Joined
Jun 11, 2012
Messages
7,046
Reaction score
7,233
Location
Water Valley, Alberta
Showcase(s):
1
Hardiness Zone
2a
Country
Canada
Welcome Art.
You'll need a new liner, but I don't know how you can do it without removing the fish.
You can just lay a new liner over the existing one, and you'll need to be watchful of ammonia buildup once the fish are in the pond with the new liner.
 
Last edited:

Mmathis

TurtleMommy
Joined
Apr 28, 2011
Messages
13,882
Reaction score
8,078
Location
NW Louisiana -- zone 8b
Hardiness Zone
8b
Country
United States
Hello and welcome!

What size (dimensions and gallons) is your current pond. And by how much are you wanting to deepen it?

One thing that stands out for me is that when you make the pond bigger by adding depth, you aren’t increasing the surface area and that’s where gas exchange takes place. Maybe that’s only a factor if you change the dimensions by a certain formula (unknown to me, but maybe @MitchM would know).
 
Joined
Jun 5, 2015
Messages
677
Reaction score
572
Location
Chicago (W suburbs)
Showcase(s):
3
Hardiness Zone
5b
Country
United States
Typically you'd lay a new one over the old one and make sure the old one doesn't hold water (trap water between the liners) by cutting some holes in it.

In the US we have intex inflatable pools which are amazingly cheap and good places to store fish while doing serious maintenance. Maybe you can find a used pool like that?
 

sissy

sissy
Joined
Jan 17, 2011
Messages
33,086
Reaction score
15,702
Location
Axton virginia
Showcase(s):
1
Hardiness Zone
7A
Country
United States
warning lay something over the top because the fish may jump out .I used window screen o my stock tank and a pump with a small filter and a aerator .Do not feed the fish and try using as much of the pond water as possible and have a water test kit handy .The fish get stressed out really fast
 
Joined
Dec 16, 2017
Messages
13,206
Reaction score
10,360
Location
Ct
Showcase(s):
1
Hardiness Zone
6b
Country
United States
If you want to save money and do more work if the old rubber isn't to old you could always splice the rubbers together
 

TRose

Sophie is addicted to watching the fish.
Joined
May 31, 2016
Messages
4
Reaction score
0
Location
Cape Carteret, NC
Hardiness Zone
8
Country
United States
I have a small pond and it was built some 15 years ago. It has a mixture of goldfish and koi in it that were all purchased when it was built. The fish have now become large but unfortunately I can't make a bigger pond due to lack of space so I wondered about extending the depth by building a higher wall around it.
The liner is a heavy butyl rubber version that is held in place by a wall at one end and slabs around the other three sides.
Obviously a new liner is needed but do I lay one over the existing one? Join Butyl to the existing one to extend it or what would you suggest?
I don't want to spend a fortune in doing it and I haven't got anywhere to move the fish to while its done. The good thing is that my existing filter box and pump will easily cope with a larger volume of water.View attachment 112146
How large (gallons) is your existing pond? What size pump (gph) do you have? How many fish is in your pond?
 

Art

Joined
Jun 18, 2018
Messages
3
Reaction score
1
Country
United Kingdom
How large (gallons) is your existing pond? What size pump (gph) do you have? How many fish is in your pond?
Hi the pond is 6x8feet and holds approximately 500 gallons. The pump is a 5500 lph and the filter can cope with 5000 gallons.
I went ott on the pump and filtration as I have appx 70 fish
 
Joined
Jun 22, 2011
Messages
4,684
Reaction score
3,759
Hardiness Zone
5b
Country
United States
Hi the pond is 6x8feet and holds approximately 500 gallons. The pump is a 5500 lph and the filter can cope with 5000 gallons.
I went ott on the pump and filtration as I have appx 70 fish
I hope you don't really have 70 fish (goldfish?) in only 500 gallons; that's a sure fire way to have issues. Before koi, I had over 100 gf in 2500 gallons and thought it was a bit crowded.
 

Art

Joined
Jun 18, 2018
Messages
3
Reaction score
1
Country
United Kingdom
I hope you don't really have 70 fish (goldfish?) in only 500 gallons; that's a sure fire way to have issues. Before koi, I had over 100 gf in 2500 gallons and thought it was a bit crowded.
Well at one point there were ver 100.
None are diseased and most years I may lose 1 fish due to old age.
The goldfish and the koi breed most years and I just simply let them be.
 

mrsclem

mrsclem
Joined
Jul 21, 2008
Messages
5,348
Reaction score
4,806
Location
st. mary's county, md.
Hardiness Zone
7A
Country
United States
@Art - how long have you had your pond? How did you go from over 100 to 70? How many koi? We get so many new members that say my pond and fish have been fine for years and now suddenly my fish are dying. The one thing that changes is the size of the fish. Larger fish- more waste= fish problems. Sounds like you are handling it with great filtration.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

Forum statistics

Threads
30,711
Messages
507,598
Members
12,961
Latest member
QIVBennett

Latest Threads

Top