Grundulis,
I love the pond. The thing that sticks out most in my mind is if you didn't say it was Latvia, I'd have thought it was anywhere in the US. I love your water control system.
The sturgeon are going to be awesome? What is the temperature range you could expect your pond to experience over the season? As in what would be the high for the year in particular as I would guess the pond will freeze over for at least a portion of the winter. Sturgeon are not quite as sensitive to water temperature and dissolved oxygen levels, but they do require fairly cool water and higher DO's, especially when larger. Not as familiar with Russian sturgeon, so I am not sure if they are more or less sensitive. A quick research on them shows they will reach 6' and 250 pounds but are slow growers... From what I understand, sterlets are one of the most tolerant of warmer waters and lower DO's. All species require moving water to reproduce so you can expect them to not multiply in the pond.
I have heard tench are very good fighters when caught on light tackle and you can't have a European pond without different varieties of carp! The one thing that seems to be missing are higher end predatory fish... Is there plans to stock any? Zander, pike, European perch, or another species I am not familiar with? Would the water stay cool enough and oxygenated enough year round for trout?
