every wall!
seriously tho, either do it or don't do it. Mincing about like this isn't helping!![]()
It's easy for you to say just go and do it but it isn't you who faces the problems if anything happens (hopefully it will not). I've decided the only way to sort this after thoroughly reading the article that refutes myths and set the story straight is to get a structural engineer out and he/she can tell me straight.
For the position of the tank, it will be against a wall and running the opposite way to the joists and will be fully supported by a few joists. I need to now work out the exact amount of weight each joist will be holding.