I understand.  The reoscopic fluid that I suspect they used can be had from Amazon.  You would have to add food coloring to get the blue color that was used in the type I have.  I thought you might be able to drill a very small hole in the top of the tank and use a 20 gauge needle and syringe to refill it.  The problem would be to seal up the hole.  I just thought perhaps someone had done this before.  Thanks very much for the info.