Not married and no kids, but the girlfriend put up a fight over cost, space, maintenance, and smell. The key to making it work is to do it right and plan everything to be little to no active maintenance. Make sure there are backup systems to reduce the risk of overflows or stagnant water. Try to balance tank size, turnover rate, plants, lighting, and number of fish to help stabilize water parameters and keep the tank clean. Automate everything you can. Since I am in an apartment I cannot easily run a drip system, but if I could I would and it would eliminate the last bit of regular maintenance I do. I know some people are opposed to automation, but remember, you can always turn it off and do the steps manually if you have the time, but if your wife/girlfriend/kid asks you to do something, saying you need to take care of the fish is often a poorly received excuse...
I run 3 planted tanks (120g, 55g, 30g) and spend no more than 30 min weekly on them (usually less). Even my girlfriend spends more time than that watching them! My tanks will all be perfectly fine if I completely neglect them for 2-3 weeks with the systems I have in place.