Hi all,
We recently bought a house in January, and the house came with a new kind of pet I have never had before, koi fish.
A few things about the pond:
- It is a mud pond, roughly 15 feet by 25 feet by 3.5-4 feet deep
- I have tested the water a few times, as the temperature is warming up, a couple of days ago I got a PH around 9. Since it's a mud pond, I can't do water changes, so I ran a hose for a couple of hours.
- That last test showed some Phosphates (between 0 and 0.25), which I am guessing might be from fish waste, we were left with maybe 30 kois!?!
- It's a mud pond, so we can't filter, but what could I add to help water health?
- I run a fountain 24/7, and a waterfall 12 hours each day.
- We don't have skimmers, aerator and so on, the previous owners said we didn't need them.
- I have been feeding them once a day high quality cold water food.
- They seem healthy and happy, a few of them are really big, and I can see them grow, one of them is around 24 inches.

Any advice for my pond and fish health would be amazing.

Also, any advice for when leaving for a vacation? We are leaving next week to go to our cabin. This time of the year, are they okay with simply the fountain on 24/7, and can they go a week without being fed?

Thanks in advance!