[Simons]

130Gal is close to 500L which is 500 kg of water alone (about 1100lbs) plus tank weight and rocks, stand and equipment I would say your estimate of 1500lbs is pretty close.

1500Lbs in a fairly small area is a significant amount of weight so it would really depend on several factors; age of your home (materials have changed) and where you are going to put the tank.

If it is going to be against a wall I would say you would be fine because the floor Joists would intersect the wall which would be the strongest point on the floor.

If you wanted to do a room divider tank then you may have to look at direction of joists as you would want to be perpendicular to their longitudinal direction so you would 'catch' as many as possible. If your place has a central support beam running down the middle of your basement, they usually have at least two telescoping support posts, so if you are close to one of those you would likely be okay. The standard support posts are designed for 5K lbs of load so there is some safety factor.

One more thing to consider, if you have a rock counter top in your kitchen (granite, marble, quartz) can add a significant amount of load. We had to install a dedicated engineering post into a friends house when he put in his 300 Gal room divider tank because he also had granite counter tops in his kitchen.