I was at a friends the other night and they had a stock watering tank (50 gal)set up as a inside pond. They had wood sides on it to hide the metal looked great! You could do the same with a black rubber one for under $100 with just a good HOb or canister filter. Good luck!
under $100 sounds good, (relatively). I'd love to have money and space for something really elaborate, but I'm currently at my parents' house and we have a very small yard, and i'm basically a student, so I don't have much personal income. The space I first thought of for a pond is below my second story window and near my parents' bedroom window, right next to a fence and under a flowering plum tree in a frustrating gravel bed full of stubborn lava rock, which I have most recently tried to work with to prepare a place for the aviary that might not be big enough for all the birds I was going to get even if my parents liked the idea enough to help. ( My friend most recently said he'd just give me his faforite bird and give the others to other people, but I haven't heard from him since.)
The most recent idea for an outside location is in the other side yard between the fence my brother just finished building to keep the neighbors' pitbuls out and a blank house wall in a corner where nobody has any reason to go or look, but I guess I would if the critters were there. I thought it would be fun to put in a small swing or something and maybe have a bridge over the pond to get to the swing, because that's about the only way it would fit. It could be cozy and shady, but it would take work, although in this spot, at least there's currently nothing but dirt because of the fence work. (the pitbuls and their people are suposedly moving pretty soon, so that would reduce noise, but we don't know who would come next.) I like landscaping, so i could really have fun if I convince my parents to support the idea, but it probably couldn't be a very big pond.
The idea that would yield the biggest and probably the easiest pond would be to adapt the spa that was there when we moved in, but never got much use because there's always something wrong with it, like leaks, or problems with heating or pumps or something. (The pitbulls already finnished off the old cover, and we are agreed that somehting needs to be done. My little sister likes the idea of turning it into a sandbox and my mom has considered trying to plant vegetables in it, but my dad and my brother might prefer the idea of fixing it to have a functioning spa, then there's the idea of removing it, but we were told it took a crane to get it in, and we aren't in any hurry to find out what that would cost. The deck around it could use some help too, mostly because of the big tree that hangs over and drops annoying inedible fruits similar to almonds, but with a seed a little more like a peach. We are agreed that the tree can go, especially since it appears to be dying anyway, but, well, you know... time, money, etc. ) It would be a big pond, and I'd probably "have to" get more fish and stuff, but I would need to convince the parents and figure out how to convert it. I don't even know how well it holds water or whether to cover the drain holes and stuff, or exactly how much water it holds. i wonder if it could be switched back if somebody decides they want the spa back, and what would be involved in maintaining a pond that size.
If I tried an indoor alternative, i don't really know where I would put it, and while I'd feel that the critters were a bit safer, I don't know if it would be big enough or how hard it would be to watch the fish and keep them safe from my 2 indoor cats.
Then again maybe I'll somehow randomly aquire lots of money and a nice big place of my own, but i don't think I have time to wait for that.
So, any ideas about the spa, or does something else sound better?
Then again, i supose i could just give my goldfish to someone who already has a pond or see how much the LPS would give me for them.