The Aquarium is supposed to write to the HKEY_LOCAL_MACHINE\SOFTWARE\SereneScren\MarineAqua rium3 key and then Windows automagically stores it in the WOW6432Node and reads from that when talking to 32-bit applications.
If the Aquarium is not using the
correct C++ programming, this could explain the problem.
The folks who are having problems -- are you on 32-bit or 64-bit version of Windows 10?