Springs under turntable

Loose marbles roll west.

And Sh!te rolls downhill......

Tomic
He obviously became completely stumped when he reached Illinois.....

Folks,
Another basic turntable question.... Where do you put the level on the turntable to balance it? Is it at the center of the platter or on the body which hosts the platter? The level position at the center of the platter for my turntable is not the same as it is on the body.

Those who are leveling at the center of the platter, how do you level it after putting a record on the platter? The center of any record is not flat and hence this question. This is more of an issue for those who are balancing a turntable over a set of springs or some float-based isolation tools. 

By the way I have tried a Vibraplane platform, incredibly heavy, to isolate my turntable from the footfall noise but it didn't work to my satisfaction. So far the combination of CSC springs that I designed along with Ingress roller bearings gave me the max isolation from the footfall issue. It doesn't completely eliminate it but reduces it to a great extent, requires a very big hit on the floor/amplitude to move the woofers in the speakers. I think that audiom3 has also experienced something similar.

It appears to me that a complete footfall isolation for my turntable placed on a wooden suspended floor would be very difficult to achieve if not impossible. I am now going to experiment with the next option of wall mounting the turntable and also use some sort of isolation (Spring or HRS Platform) to get to the desired level of seismic isolation.... 
Thanks.

I use the level on the turntable plinth. Left to right, front to back -both sides. If the platter is not level and the table is level, something may be amiss.  
Can you reinforce the floor beneath your room? Lally columns will help.