Hmmm well this is a funny topic. Brit and I don't share our finances except for bills which we use a common joint account to transfer JUST bill money to to pay everything with. If she knew I have 5 grand in a 25 gallon(that's including f'ups too) well..who knows lol
When I was fishless she didn't understand...when I was building my new tank she didn't understand, when I bought her a kitty w/ healthplan & tower & window bed & water fountain she started not caring what I did. Now she takes care of the kitty I take care of the tank(diversion haha). But now that the tank is relativly stocked I catch her watching it or trying to sneak some food in, but always catch her quick...woman you better go rinse them hands in vinegar get that damn soap and lotion off before you go stickin your hands in my tank

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So moral of story, she doesn't ask the cost, I don't tell. Use diversion & give her a hobby when you've started a hobby. Keep finances separate, keep her involved, tell her what everything is, ask her opinion on things and placement and colors you want to highlight...but don't take them equipment shopping..Lfs is ok when shopping for fish/inverts. But don't take them coral shopping..lol
Brilliant. My fiancé knows how expensive my last tank was(120 gallon). But I'm sure she thinks the nano I recently started will be relatively inexpensive. Who am I to deprive her of her assumptions? lol