Concrete Pond Construction

Frequently asked questions about small ponds, plants, etc.

Q. With regard to the filter system I am intending to use a water pump fed external filter the type that is available commercially together with a uvc & magnet I like the vortex 2.500,I wonder wether this set up would be suitable for my size of pond, also what height the filter outlets should be in relation to the pond water level.

A. I do not have any information on these commercial filter systems so I cannot comment. It is best to get the advice from the manufacturers so you can then go back to them if it does not work the way they say it should.
With small ponds many people do use a water pump external filter, but these have a disadvantage of "liquidising" any droppings etc in the pump and so becomes more difficult for the filter to remove the solids.
The return to the pond from the filter needs to generate as much oxygen as possible. You could have it running over a waterfall, or you can run the return just below the pond water surface and fit a venturi on the end of the pipe.

Q. Is it true that frogs/plants etc. and Koi don't mix. The reason I ask is that one of the best features of my present pond is that other wildlife (frogs in particular) seem to thrive with no adverse impact on my fish. I happen to like frogs but can't see a way to allow them access to the new pond. Also. although I want to keep Koi 'properly' I would also like to transfer a couple of lilies across etc. to encourage wildlife. If its a straight choice between wildlife and Koi then the Koi win hands down but if I can combine the two to some extent that would be nice. What is your opinion on this (i.e should a Koi pond be a 'sterile' environment or is there some 'safe' latitude on this)?

A. This is my personal opinion but also followed by many koi-keepers. Frogs are definitely out. They can bring diseases and they have been known to try and mate with a koi by hanging on to the head and prevent the koi from breathing. One South Wales koi-keeper had an excellent photo of this taken in his pond. Frogs will not be able to get out of the tppes of ponds fearured on this website. If you are keen on wildlife ponds with frogs etc why not convert your old pond. A wildlife pond should be reasonable shallow with sloping sides. You can have a couple lilies if you insist. It would have to be a variety that can stand the depth. The fish will dig in the baskets and put dirt in the pond. The fish can easily damage themselves on the stems, and the large ones can eat the new buds. Not to be recommended.

Q. Please advise why your construction plans are designed for ponds without plants?

A. It would seem that many koi-keepers in the USA do like to have plants in their ponds, but in the UK and Japan you rarely see plants in the pond, although some people do have them in another pond alongside. I think it depends on wether you want to have a general pond with fish, or you wish to have a dedicated pond to show off the koi to their best. A lot of these fish are quite expensive and so you need to be able to see them.
The general reasons for our way of thinking is: -
1. Most of the ponds are five to six feet deep so having plants would be difficult.
2. The soil in the pots spill out into the pond and discolour the water especially as the larger fish are looking for grubs or insects in the soil.
3. The fish quickly grow to 24 inches and above and can very easily damage their fins or bodies as they swim against them.
4. Our aim is to have very clear water so you can see anything on the bottom of a six feet deep pond, and this is almost impossible if you have plants and soil.
5. The ponds are there to show off the fish to their very best, and this cannot be done if they disappear under or behind plants when you are looking at them.
6. We often consider it adviseable to dose the pond, say once a year, with chemicals and/or salt and to do this you would have to remove the plants.
There are many levels of koi-keeping and it depends what you wish to do. Many people are keen to have a very natural type of pond that fits in with the rest of the garden, whereas these ponds featured on the website are there mainly to show off the fish to their very best.