Interestingly enough, I had (key word, had) a spreadsheet setup to monitor costs (borrowed the kill-a-watt from work to get baseline electricity usage), the cost of mother colonies (or more often than not, the "cost" assumed in electricity and such to take frags from my tank at home and grow them out to "mother colony" status to begin the fragging in the frag system). I also monitored things such as the cost of salt, and everything up to and including the dual gang electric boxes used to wire the thing. Freebies and things I had laying around not counted in the setup, and JUST the setup of my system alone cost nearly $500. Thats 2x 30gal breeder frag tanks, 2x 25gal sump/fuges, and 1x 30gal sump. The pumps and lights and stand required to run it etc. Keep in mind that things such as water were "free" but I had to lug water from home in gallon jugs. What a PITA.
I'd be in the negative if it werent for the fact that school got in the way and I had to shut it down. Now that summer is rolling in, I
should have more time to work on it and get it running.
I figured out that the best way to make a return on my money wasnt with the cool corals, it was with the weed corals; things such a xenia and green star polyps sell like mad, grow quickly, and are easy to frag - which makes up for the fact that $5 frags doesnt make a ton of money quickly. When I get it running again, I'll be dedicating one tank to growing out xenia frags, and the other for green star polyps and some cooler zoanthids.
As said above, if you're looking to do this for profit, you need to read though soem of the other threads (I'd get some but search isnt working and I'm lazy tonite
) concerning profit making techniques such as air lifts for flow, stock tanks for grow out tanks, and massive systems.
At home, the 40gal frag tank is enough to allow us to buy a new coral or fish every so often, but all things considered, its a negative investment as well, because we arent using it to pay for the cost of electricty to run it or the salt and such for water changes.