To add to this, ideal temperature is 16C to 18C (we use a Pi to keep a running graph of the temperature). Lower is generally ok, apparently if it gets into the

To add to this, ideal temperature is 16C to 18C (we use a Pi to keep a running graph of the temperature). Lower is generally ok, apparently if it gets into the mid-20's they get so stress they try and escape the tank. We have a chiller, though we have also used the fairly common trick of putting ice bottles in the tank as needed (milk containers filled with water and left in the freeze for 24 hours work well).