Tako,
I'm sorry if I was a bit rough, but I do have opinions on this. A lot of us have spent big money to make safe habitats for our animals. I'm worried about your octopus because you can't seem to afford much equipment for it, you don't know much about the other animals that you put it in with, and without a test kit you can't tell how much poisonous ammonia is in the water.
I'm not going to tell you that you shouldn't try to keep an aquarium and I don't want to make you feel bad. I just think you're moving a bit fast and should slow down a little. There are other kids on TONMO who have no money and start slow, keeping local crabs and things while they buy equipment over time.
Let me share with you my experience:
When I was about your age I saw an octopus in a pet store and fell in love with it. I didn't have any money and when my parents wouldn't pay for all the equipment. This was well over ten years ago, long before TONMO. The store tried to sell it to us, told us that it wouldn't need much equipment, just a small tank and an undergravel filter. We knew it was being pushed on us and it didn't sound right. We (read: my mature and responsible parents) decided that since we were unable to give it a good home we wouldn't take it. I was a kid with no money and no job and if that octopus died in my care it would have been my fault and mine alone for putting it in that environment.
Only in college did I discover TONMO and my interest in cephs and aquariums came back. Once again I knew I wasn't ready for an octopus, so I bought a used 30 gallon tank for $20 and kept clownfish. It was very hard because I didn't learn about the nitrogen cycle like I was supposed to and killed one of the clownfish. I still feel bad about that. It wasn't until that tank was set up for over a year and I had fixed the previous mistakes did I think about setting up a tank just for an octopus. And after I bought the 75 gallon tank for the octopus I spent a year and a half playing with different types of filtration and plumbing before I settled on a configuration I liked.
During that time my patience was tested as I kept being unable to get my octopus. I ordered one from Octopets but it was really tiny (smaller than a dime) and died very quickly. The next time Octopets had any in stock I was going to move soon and was worried it would be too stressful for an octo. The next time they had some my tank was still cycling. When my tank finally cycled I found out Octopets had gone out of business and I desperately tried to find some other octos or even eggs. Now six months after that I have two adolescent cuttlefish that keep me very happy.
This hobby rewards patience and often punishes eagerness. You can do it, but I think if you slow down a little bit you will be rewarded, too. You won't have to lose any sleep worried that your octo might ink during the night and die before you can do a water change.
Dan
PS - My aquarium system cost over $1000. The protein skimmer I'm using in it right now cost me $5 used. You can get a lot of good equipment real cheap, you just have to be patient and snoop around!
