Koi pond in the basement

I recently had dinner with another landlord in the area.  He has just one rental property and he told me the story of some tenants who decided to become entrepreneurs.  They decided to raise Koi fish and sell them. 

Well, what he found is that they didn't just decide to fill up a kiddie pool in the basement and raise them there -- no, that wouldn't give the koi enough room to swim around in.

What they did is take the entire basement area (minus the area for the furnace and water heater, luckily) and flood it with water and let the koi swim around there!

Cleaning up the basement was such a big mess after he got them out of there.  Not only did he have to deal with the water, but there was algae, and fish excrement on the basement floor.

Two lessons to take away from this experience:

- Monitor your tenant's water usage.  If you see it going up, they could be doing something you don't want them to do.

- Have regular inspections.  Check every room in the house including the basement.  You never know what you're going to find.