I've worked in the aquarium business on and off for most of my life and I can tell you that there is a huge demand for people who are willing to clean aquariums. Why anyone would want an aquarium but not want to clean it is beyond me but that opens a huge door of opportunity for anyone with a little bit of a work ethic.

To do this, you really need to be a fish guy (or girl) because you will come up against all kinds of weird problems and you need some background knowledge to handle these problems. Working in an aquarium store part-time for a while is a good way to get experience but don't stop there, volunteer to clean tanks for everyone you know. Do this with an eye toward getting a system down so you can get in and out of accounts as quickly as possible while still getting the tanks as clean as possible. Remember, when people are paying you for this they are going to want results.

While you are getting your system down, you need to think through how you are going to handle things like water changes, algae covered plants & decorations, muck, slime, green water, milky water, and so on. Your clients are expecting you to be an expert so you had better be or they won't be calling you back and they sure won't be referring other people to you.

If you are wondering how much money you can make, plan on charging between $40 to $75 and hour. I would call around and get quotes from other companies and try to be competitive with them. I used to know a guy who charged a fixed amount for a service call and then a dollar a gallon. That was quite a while ago but you could use a similar formula for yourself.

And finally, make sure you treat this as a real business. There are countless resources on the internet to help you get started but plan on spending a few hundred dollars on a lawyer so that you don't end up in trouble. This is a very simple business to operate but don't make it so simple that you screw it up.