Leveling concern?

[tomreefer]

Ok I am starting to put water in my tank and I leveled my tank. Hiwever, my floor is off a lot as seen in pictures. This tank is on second floor 75 gallos with 20 gallon sump.. U think im safe?

 

[davocean]

If that is just one shim I would not call that terrible, not ideal of course but not terrible.
That in itself should not be an issue, and you should add other shims every 6" or so to take up the rest of that void along the length of tank.
I can't tell you you are secure on a 2nd floor w/out knowing what your framing is like or where positioned, hopefully near a bearing wall so framing is solid, hopefully spanning several joists and not parallel and only on one or two, but generally speaking a 75 should not be a big deal on a second floor w/ sound timbers

 

[tomreefer]

actually I got a whole board 1x4 inch I felt it was safer than shims. Its across the boards

 

[davocean]

I'm not sure I'm following correctly, do you mean I'm looking at a 1x4 or did you cut a 1x4 to follow how much it was out?
Shims alone are used by about everyone here, and perfectly safe.
Huge deviations may be dealt w/ differently

 

[tomreefer]

yes I tried shims but was a lot. I had a piece of 1x4 and put it under the stand and now it's level. I figured a 1x4 would be safer since its off a lot

 

[davocean]

Ah, well often we double or even triple stack them.
I would just make sure it is not lifted off 3/4 at one end and nothing else from that end to the other, add some shims spaced about 6" or so to prevent from sagging.
I'm a carpenter, we put shims under huge islands w/ granite tops, they don't really crush or fail under that weight or under our tanks