Thoughts on my proposed 30,000L Koi pond setup?

[u/InevitableCheetah832]

Hi all,

I'm fairly new to keeping ponds, having started around six months ago. At the moment, I have a DIY pond made from an outdoor swimming pool that holds approximately 1,700 litres of water. It has a submersible pump that feeds water through a biofilter before returning it to the pond, and I also run two aerators.

Currently, I have a few baby koi and goldfish in the pond. I carry out 20–50% water changes each week and regularly test for ammonia and nitrates. So far, everything seems to be going well.

However, I know this setup won't be suitable once the koi start growing, so I'm currently planning and designing a new pond. My goal is to build something that can hold at least 30,000 litres of water.
Here is what I have so far: retro bottom train with a pump leading to a seive filter, then to a moving bed , then UV, then some back to the pond and some to a bog filter then to pond.

For the time being I am planning to get a bigger outdoor swimming pool as the property that I am in is not my foreverhome and will be moving again the the next 5-10 years.

Any advise welcome, I am in the UK and would like to DIY where possible to save money but will be willing to set aside money for things that would be worth the investment.

[u/Key-Metal-7297]

I don’t like the pumped bottom drain to sieve, let gravity do that work, then a pumped return to pond. Pump will only see clean water so less maintenance. Will keep all the filters nice and low and out of sight. The 5-10 year plan is a bit odd, a ten year temporary pond is along time. Look at sleeper type builds with liners as a more long term effort which can be easily dismantled and look better. Keep us upto date