My stand rocks back and forth a bit

[TheEngineer]

You can cut holes in the plyboard to pass plumbing & cables through.
I would board both ends fully as per my diagram, & most likely the rear side as well to be on the safe side & peace of mind.

This.

 

[SallyWho]

You can cut holes in the plyboard to pass plumbing & cables through.
I would board both ends fully as per my diagram, & most likely the rear side as well to be on the safe side & peace of mind.

Cool, I'll give it a shot! But, um, how do I cut holes big enough? I have a 1.25" hole saw, but a crappy drill (never buy a cheap cordless drill, because you'll spend enough money on spare batteries that you could have afforded a better drill with a cord so you wouldn't need batteries at all). And my circular saw, despite the name, only cuts in straight lines. What sort of tool will I need to borrow/rent/buy in order to cut a circular hole in various diameters? There are other things I'd like to do requiring a large-ish round hole, too (like for circulation fans in the canopy), so the timing of this recommendation is perfect!

 

[Scrubber_steve]

Cool, I'll give it a shot! But, um, how do I cut holes big enough? I have a 1.25" hole saw, but a crappy drill (never buy a cheap cordless drill, because you'll spend enough money on spare batteries that you could have afforded a better drill with a cord so you wouldn't need batteries at all). And my circular saw, despite the name, only cuts in straight lines. What sort of tool will I need to borrow/rent/buy in order to cut a circular hole in various diameters? There are other things I'd like to do requiring a large-ish round hole, too (like for circulation fans in the canopy), so the timing of this recommendation is perfect!

Depending on the opening size you need you can use hole saws. They come in a set or singularly. Or if large space is needed a jigsaw.

 

[TheEngineer]

Depending on the opening size you need you can use hole saws. They come in a set or singularly. Or if large space is needed a jigsaw.

Again. This.

 

[Ferrell]

Skinning the sides will help a lot
And keep it square. Nice job!

 

[Kmack0415]

Mine did similar after building, I have mine in carpet and skinned after filling it is solid, I can get movement if I try but I am 100% confident that it is strong and stable. My sump stand, 125 on similar stand, on my unfinished wavy concrete floor was pretty bad to, I shimmed that filled and it is strong like ox now lol. The diy stands we build are ridiculously overbuilt for the load they hold, I would test fill it, make sure your still level and shim if needed.