I decided to add some Snails and Shrimp about one week ago. I took the recommendation of another natural aquarium hobbyist and added several Physa fontinalis, Planorbella duriy, Melanoides tuberculatus, and M. maculata. I also ordered five Shrimp, Neocardidia davidi. To add the shrimp this early was my own decision.
Unfortunately, almost every creature died. I think the Physa fontinalis which live in the soil may be still alive. I think they died because of the extremely high temperatures. The heat wave caused the temperature in the tank to rise to steady 29 °C, some days as high as 31 °C. Of the five shrimp I only saw one yesterday, none today. I think they are all dead now.
I was changing about 40–60% of the water every day or every other day but it did not save them. Several times the water has foul smell of reminiscent of decomposing fish I smelled at the shores of the North Sea and the Baltic Sea.
Once the heat wave is over, I’ll try to repopulate the tank.