Too Many Koi

 I'm going to have to get rid of some of these koi before much longer.

They're certainly becoming more tame with the feeding ritual. When Hay gets into the water for her morning swims they mob her and nibble at her legs.

There are more than the ones you can see - there's at least 5 black ones which are difficult to spot. One is rather nice, having a silvery underside and jet black topside.

I feared I was overfeeding them, as I'm starting to get blankets of filamentous algae in my physical filter mats. That's usually a sign to too much nutrient from uneaten food. Once a day, with enough to last 2 minutes is enough, by all accounts. 

As a precaution I did a pond test with some strips and fed the results into Chat GPT, which came back as follows:

"Your pond water parameters look quite balanced, with just a few things to note:

"pH (7.4): This is within a good range for most pond fish and plants. Slightly alkaline, which is ideal for fish like goldfish or koi.

"KH (15 dKH): The carbonate hardness (KH) is quite high. This means your water has a good buffering capacity, which helps prevent sudden pH swings. This is good, especially in outdoor ponds.

"GH (10 dGH): Your general hardness (GH) is moderate. It suggests there's enough calcium and magnesium in the water, which is beneficial for fish health, shell growth in snails, and plant vitality.

"NO3 (Nitrate) 0: Having zero nitrates is unusual in established ponds, as it's typically a byproduct of the nitrogen cycle. If your pond is relatively new or well-filtered with lots of plants, that could explain it.

"NO2 (Nitrite) 0: This is ideal, as nitrite is harmful to fish even in small amounts.

"Overall, your pond seems to have stable, healthy conditions. If you're adding plants or fish, it should be safe to do so based on these readings. Just keep an eye on the nitrate levels to ensure the nitrogen cycle is functioning properly."

So, everything is looking just fine.