I want to post about aquarium water pumps, after reading a topic about a homemade water jacket.
I would like to alert to those who use this kind of pumps, specially the AC powered units (I used a 220volts one inside my Jobo CPE-2 for a long time). This pumps are commonly sold in Europe, most of them without an adecuate (in my opinion) warning sheet.
This pumps are made for aquarium use "only". They must be installed only about 2 cms. deep, with the power cord outside the water surface. Some of them can be used submerged.
Take note that the power cord is sealed to the pumpīs box. If the sealing compound or pump-box is damaged (it could get crystallized or separated by any reason) and current get in contact with water, you can suffer an electric shock, as you can know.
EU automatic security switchs must be tested periodically, but usually nobody does it (including me). I have been surprised with three non working switchs of four at the locations where I live, work and visit. In this case, the electrical shock could be extremely dangerous. Just this.