I would have to agree with Maureen.
2c
Your wives are actually taking an interest that can be developed into a team effort. Squashing that interest will result in this being a loner hobby (and one with a smaller budget)!
There will be errors by spouses as, quite simply, you built the system, now maintain it and have probably invested hundreds (thousands?) of hours in understanding it. How about all the errors we all make, but since it's just us, no one need know! With two knowledgeable aquarists, errors become explicit - both your errors and your spouses. It makes us better aquarist.
BTW (back to work)