Well at least I'm not the only one in my household. But it can be really fun. The past week has been a great example of this.
For our 4th anniversary last month, my wife and I bought a 56 gallon freshwater setup. At the time we had a 10 gallon setup and 2.5 gallon that we were using to house babies from our livebearers. (Platy/swordtail hybrids, I think.)
That was about 3 weeks ago.
Today, we have a 46 gallon bow front, a 20 gallon, and another 10 gallon. Plus the 56 gallon and original 10 gallon tank. (Now both my of my daughters have their own 10g freshwater setup, the wife has the 46 g for her community ... mostly she wants a home for more more mollies and a peacock eel, but also probably some angels and a few red-eye tetras.)
The pet store had a sale. We uhm, went a little crazy. (A complete 20G freshwater setup was only $40.)
The 56 gallon display tank (24" tall) got converted to saltwater. This is my first marine tank. I only got it filled up last night. (And let me tell you, at about $5/lb, live rock is expensive. Between live rock, live sand, and water -- 89 cents/gallon, I've already spent about $300, and I've not even put any fish in it yet! That doesn't include the tank and equipment of course.) The setup is going to be a FOWLR (fish-only with live rock) tank.
To really get the full picture though, you need to picture me standing out in the cold wind and rain, in wet jeans, barefoot, hosing the 56 gallon out to make sure I've flushed out any freshwater bacteria properly. I must be half nuts. But Debbie came out and helped me, so I'm not the only one.
What is really cool is that my wife has had as much fun with this as I have. I am fortunate indeed to be married to a woman who enjoys so many of the same things I do.
Now we just need to wait.... and wait... and wait.... (New salt water tanks need to "cycle" for about 3-4 weeks before adding fish.)