Well...I like what ST suggested. My 2 cents is to get the goldbulb as soon as possible. You can sell them for as much as 50 with little trouble if you want and you can get money for whatever sooner. I would then buy the second tank first then buy the enviroment researches. Ignore anything else. And indeed, unless you have the money to buy cures all the time, dont bother. Course if you want to try and trash as few fish as possible...that wont help there.

Other then that, I agree with ST. When you get as much as possible, try and get the canary firearrow as soon as possible. I sold them for $300 excellent, but you can actually get 375 just fine too. If you cant figure out which to crossbreed, just try the mutating potion (unknown chemical) and you might be so lucky as to get yourself a couple of canary firearrows. You can also use the mutating fish to try and get it if you want but that will take much much more work. Dont bother with groth hormones or advertising or ornaments. those are just a waist of money at first. You can always do that if you want to but thats your choice. As for the growth potion. I would only use it when your sale tank is 100% full and you may need to also buy 2 bottles...but that isnt bad. If you earn $300 per fish even...you only need about 3 bottles which is 1140 altogether. that still gives you a 71860 per each selling of sale fish.

hope this helps.