150gal....weighs about 650kg/1400lb too much for upstairs unless you have concrete floors or have it checked by a competent person ie a structural engineer,
With the questions you are asking I would really suggest you have the tank made for you, not trying to be rude or clever, but with a tank that size you are going to have some serious problems if it fails, and being upstairs you have everything below to think about too. If you build it yourself you may well end up liable for any damage (property and building) and also find you insurance is not interested.
Tank building is not difficult, I do it regularly, but big tanks & inexperienced builders are a recipe for some real grief. It will probably be significantly cheaper to have it made/off the shelf too.
With the questions you are asking I would really suggest you have the tank made for you, not trying to be rude or clever, but with a tank that size you are going to have some serious problems if it fails, and being upstairs you have everything below to think about too. If you build it yourself you may well end up liable for any damage (property and building) and also find you insurance is not interested.
Tank building is not difficult, I do it regularly, but big tanks & inexperienced builders are a recipe for some real grief. It will probably be significantly cheaper to have it made/off the shelf too.