> Hate to ask this, but how expensive is expensive? I've found several > starting a $79.00 up to several hundred dollars. Will the probe be > run in line? If so I have found one with a flat electrode that is > designed to stay clean for I think $115.00. Pet Warehouse or That Fish Place have a Boadley-James "Silver" electrode listed for $33 or so. We have three of these and they seem to work fine - at least as well as the $90 electrodes they used to sell. George