2x6s cut to level tank, attach or not attach?
So I cut 2x6s using a compass and jigsaw to level my tank on my brutally uneven concrete floor (its safe, it was built uneven to slope towards a drain in the center of the room, its an old firehouse garage) and I put them on the ground in a rectangle with the longer side standing up. Then there are 3 2x8s placed across the top long side down. I put the tank and stand on and made sure it was level. My question is should I attach the pieces to eachother or just let them stand as is, there is a decent amount of shimming involved so I worry that if I attach them they won't sit properly and will be uneven again.
Will the weight of the tank be sufficient enough to hold them in place or do I need to worry about things shifting out of position and collapsing.
Thoughts on this?
Here are some pics