Speidel tanks are of great quality. The tanks in the picture are 300 liter versions, variable capacity/lid. I also have one of 100 liter capacity but can't find a picture that fast of it.
I am using cooling hoses. So far I cool through tab water, but I am thinking of getting a glycol cooler. The tab water temperature at this moment is 7 degrees C, but in the end of September the tab water is much higher in temperature and not ideal to cool.
The tanks have a temperature sensor to turn off the valves in the cooling hoses.
I was wondering what the blue tubing was in the first photo, understood. Thank you. The tank cover hava a tapping for the hose or did you have to retrofit?