Hagen Marina Plastic Thermometer Aquarium Thermometers at Linens 'n Things

On September 16, 2010:
I use these thermometers almost exclusively, because they can be placed anywhere in the tank without interfering with the lids/covers on my 45 tanks. The numbers are big enough to be seen at a glance (without my reading glasses). The only problem is, that after a few months, the glue used by the manufacturer fails and the glass tube comes off of the plastic. I solve the problem by placing a dab of silicone at the top and bottom of the glass tube before the first use.