View Full Version : Some questions before I start building my first Koi pond

07-08-2016, 02:31 PM
Dear Koiphen forum member(s)

I've been thinking about constructing my own Koi pond. It will be my first ever Koi pond though. So even after doing lots of research, I still have some questions before I actually start constructing it.

1. Pond size
The pond that I would like to construct is: 2m (width) x 2.5m (length) x 1.5m (depth). Is this a good size for a pond with 2 koi's and a handful of smaller fish?

2. Filtration
This is the hardest part for me. I've done some research about Koi Ponds, so I have a plan for the filtration system.
I want my filtration system to be gravity fed. This seems to be the best way of keeping a pond clean. With this in mind, I would have a setup like this:
- Fish-safe skimmer
- Aerated bottom drain in the middle of the pond
- Connect both the skimmer and the bottom drain to a filter that is placed next to the pond
- I will have a mechanical filter, a biological filter, and also a UV light
- Then I will have a pump pulling water from the filter back into the pond
=> Via gravity, water will flow back to the filter at the same speed as it is pulled out of it(?)
=> Also, this pump would be on the opposite side of the skimmer, so that the water is pulled into the skimmer

Would this be a good (and a possible) filtration system?

3. Pipework
The pipework is something that also concerns me. Let's say the skimmer needs a 3 inch pipe, the bottom drain 4 inch, and the filters have a 2 inch pipe entrance. (Worst case scenario).
Is it then possible to just connect those up anyway, or isn't that a good idea? (Is it better to have for example 2 inch pipes for everything)?

4. Decoration + form of the pond
Is a strictly rectangular pond with the above mentioned size ok? I would just dig a hole straight down for 1.5m, making it 2m x 2.5m wide / long?
=> Except for the bottom, that will have a slight slope towards the bottom drain of course. :)

5. Thanks
Thanks for reading until here already! And thanks for the eventual replies! :)


07-08-2016, 11:26 PM
It would be better to not tie the BD and skimmer together, it is very hard to adjust the flow. It is best to run them on separate circuits with their own pumps the advantage is that if one pump fails you will still have another circulating water. The size of piping is determined by the amount of flow you want, external pumps usually have from 1 1/2" connections up to 3", gravity pipes like BD pipes need to be sized according to the flow to ensure there is enough flow to keep it clear of debris, larger pipe will flow the same amount of water at a slower speed but if it is too small it won't allow enough flow for the pump. Hopefully you will get some replies from the real experts on here, keep reading through pond build threads and post your plans here, it will save you from making the mistakes a lot of us have made. And welcome to Koiphen!


07-09-2016, 12:17 AM
You need to watch this series. It will answer ever question you have and save you from grave mistakes http://www.youtube.com/watch?v=YC-RVqsEmsU&sns=em

Sent from my iPhone using Tapatalk

07-09-2016, 12:44 AM
Going bigger would be better if at all possible. Keep in mind that your koi may be 70-80cm long eventually; 2.5 meters doesn't allow much room to swim. Can you do 3m x 6m x 2? 4x8x2 would be even better, but we all have space restrictions :d: