oh wow, thats even bigger than the one i saw, i couldnt imagine a tank that size.
honestly though with the cost of aquarium equiptment, if you want to go bigger id say go as big as you can afford as soon as you afford...
we played the small to bigger game when i was younger, starting with a 10 gallon and working up eventually to a 40 gal...but in the end we ened up with a small fortune worth of fishtank equiptment most of which was sitting unused because we didnt want 10 fishtanks all set up at once.
ende dup selling everything before we moved to the US...once here we wanted another fishtank but decided instead of making that same mistake we were just going to "go bigger" from the beginning. its saved us a fortune on equitment (costs more upfront of course...) we also got equiptment rated for tanks bigger than we planned incase we ever decide to go even bigger.
right now ive got my cichlids in a 39gal tall, but all the equiptment beyond the tank/hood/stand are rated for a tank up to 75 gals...
once i get my own place ill be on the look out for a 55 or 75 to set my cichlids up in and at least i can just transfere all my equiptment over (the 39 will eventually become a marine tank
, i already have most of the equiptment i need for that lol and the tank is tall so perfect for settig up a small reef)
and we use my 55 (origionally my cichlid tank *grumbles*) as the over winter tank for my mums pond fish, its too small tank wise for the amount of fish in it but its just for the winter right now (hoping to make the pond larger this year and deeper and get a little pond heater so they can overwinter outside)
but the filtration on that tank will handle 200+ gallons.
i think going bigger NOW will save you money in the long run...if your planning a 500gal eventually
id make my next step a MINIMUM of a 55gallon tank, (a 125 would be even better) itll give you a much better idea of how to handle a larger tank...while still being easy to find all your needed equiptment (most pet stores stock or can easily get equiptment to handle up to 125gals...after that equiptment becomes harder to find...)
the biggest problem with a 500 gallon tank will be weight, this is why most giant tanks are done in acrylic or polymer based "glass" because the tank ends up about half (and often less than half) the weight of the same sized tank made out of glass...
MOST homes are NOT built in a way to sufficiently support the weight or a tank that large, especially if made out of glass.
i know a standard glass 180 gal aquarium weighs about 340lbs EMPTY, a 500gall glass aquarium would require thicker glass than a 180 so id say a good guestimate would be to to estimate a minimum of 1100lbs JUST for the tank.
then theres the cost of your stand unles it will be on the floor, plus the weight of your hood/lighting. so id say a minimum of 1500lbs right there...probably more as i dont think your want a simple wood stand for a tank that large...
then theres the weight of the water which weighs 8.5lbs per gallon, so right there is another 4250lbs...
then theres the weight of your filtration systems and additional equiptment so id say your now at about 6000lbs.
then theres substrate (you coudl go bare bottom to save weight but i hate bare bottom for display tanks lol) general rule of thumb is a minimum of 1lb substrate per gallon of water, so were now at 6500lbs.
then theres your deco...if your planning on doing driftwood, or rocks ect that will all add to the weight...too.
most homes floor joists wont support that kind of dead weight...do youd want a floor that is NOT joisted, youd essentially want a flat concrete reinforced floor to sit it on.
if you whent with acrylic youll end up at about 1/2 the weight of glass knocking you under 5750lbs...
but youll also pay about double the cost of glass...lol
definatly not a project for an apartment, older home, upper floor, ect..infact i think id probably want to build the house around a tank that size or build it its own room with specialized flooring lol.
and definatly not a project thats goign to be nice on your checking account lol...
would look fabulous though!
id LOVE a huge tank one day, but my max is 175gals LOL!