Hydroponic Fan Speed Controllers Automatic fan controllers provide control over the temperature of the growing environment. SMSCOM Temperature Controllers SMSCOM Smart Controller 6.5A + Sensor (on SALE!) $144.95 $114.95 Hybrid Twin Controller- SMSCOM (on SALE!) $299.95 $229.95 Hybrid Controller Pro 4A – SMSCOM (on SALE!) $489.95 $399.95 Hybrid Controller Pro 8A – SMSCOM (on SALE!) $599.95 $499.95