LINN AQUA-CONTROL - the life insurance for your fish! In order to protect yourself from unpleasant surprises and to increase safety, it makes sense to install a monitoring and alarm system. Safety is provided by constant monitoring of the oxygen content by means of electronic probes directly in the pond. Based on this idea, LINN Gerätebau has developed complete monitoring systems, which are now in use in almost 200 fish farms throughout Europe - individually tailored to the customer's system