You wouldn't place it with 2 boards running parallel? would you place it with the supports running perpendicular so there is like 6 or so under it?
180g is really pushing it. Could it be fine? Maybe ... depending on the type of floor joist (2x, engineered wooden I-beam, wooden truss, etc.), the spacing of the floor joists, the span of the floor joists, the subfloor material, the floor materials, etc.
If you want to know for sure if you could simply put the tank up and get away with that much load ... regardless of whether its near a load-bearing wall ... without adding any additional support, the best bet is to have an engineer look at it and do the math.
The second option, if you don't want to pay an engineer, is to add non-flexible (e.g. metal, concrete, or cynderblock) supports in the basement beneath it.
If the ground in the basement is concrete or really solid stone, it could be as simple as setting up a pair of jack posts:
https://www.lowes.com/pd/Akron-108-in-Adjustable-Jack-Post/3475337
If it's just a raw dirt floor, you'd have to pour concrete footers to place the jack posts on.
But some type of additional support under the joists would be a smart move.
The problem isn't the tank suddenly falling through the floor...
It's that the floor will begin to sag more and more over time. Furniture won't sit level. The floor may begin exhibit bounce as you walk on it. Stress at the base of the walls could cause cracks to appear in walls. Stress could begin to cause flooring materials to crack (leading to eventual failure issues). All of which will, of course, also devalue the home ... and, believe me, buyers will notice a sloped, saggy floor, bouncy floor the moment the walk on it.
This article contains great info and insight: https://badmanstropicalfish.com/articles/article28.html
This ReefDudes may be worth watching too: