One of the best ways I have found to enjoy my tanks while saving money is to buy fish that reproduce in my tanks. I then sell them back to my LFS. I also have a 10 gallon guppy tank so I have tank raised feeder fish for my other 2 tanks. I have been known to drive around certain area's on garbage day, and have gotten a few 29 gallon tanks, and 4-5 10 gallon tanks this way. The best way to make this hobby pay for it's self is to breed fish that are typically hard to breed, or hard to find. Selling snail free healthy plants is another way to make your money back. I have started turning all of my tanks into planted tanks, and as soon as I have enough for all 3 of my tanks to be heavily planted I will be selling the cuttings, or off shoots. If you have a flower garden, or vegetable garden you can use the water from your water changes to water the garden. The extra nutrients in the water is great for promoting growth. Growing your own brine shrimp, micro cultures, and other live foods is another way to save money, and make money too. I've been toying around with an idea to start growing some of my plants in jars on the window sill to start my plant selling business. Another thing I've been thinking about, is selling seeded sponges for filters. There are so many people who want to kick start there cycle, I'm sure there would be a market for them. I get most of my river rocks from craft stores, as well as my filter floss. I know there is someone on one of the sites I frequent that has a person who makes manzanita driftwood packages also. I also recylce a lot of stuff from around the house for decorations in the tank. I have used hard plastic bowls cut in half to make caves. I have also used habitrail peices as tubular caves.