Would you use these to build a stand?

I'm basically turning my bedroom into a fishroom - on a budget. That means building stuff as cheaply as possible, so I'm using 2X4's and cinderblocks to construct my stands.

For example:

To hold my 55 and my two 20 longs, I'll have 3 cinderblocks (on the floor), spaced 20" apart. Then I'll have two 64" 2X4's sitting on those blocks to support a 55, which should fit in between stacks of cinderblocks on the end. I'll stack 4 more cinderblocks on the end of the "stand", put two more 2X4's, and put my two 20 longs up there. It won't be pretty, but it's cheap, functional, and sturdy. I don't know if that third cinderblock in the middle (on the bottom) really does anything, but it makes me feel better. I'd think it'd distribute weight more evenly.

I'm building several of those using these cinderblocks:

However, for my rack of 40's, I'm more limited on space - I need 52" to fit the tanks and cinderblocks, but I only have 48" available. I can either get rid of one of the 40's (which I really, really don't want to do), or I can use these cinderblocks:

They're half the width of the others, which would make that stand 44". Would you trust these cinderblocks? I don't see why they wouldn't work, but I don't know much about how they "work" so to speak - if there are certain kinds which hold weight better, or if there are some that will crumble after a few months of use, etc... I know the others work because I've seen them used in aquarium shops for years.

Thanks!

 

I'm no carpenter but if you've seen the stands sold for tanks that size compared to what your building I think I'd trust your stand over what is on the market

 

I agree with Zachsnanotanks! And If u really want to be sure, drop by a fishstore or home depot. They can assure u or perhaps advice some changes

 

I have 3 tanks on cinderblocks... you can still use the 8x8x16 just let the wood overlap the blocks but either way the skinnier cinderblocks will still hold everything no problem. Here is my 20-29

 

They'll be fine. Make sure you place all the cinderblocks with the holes up and down and not side to side.

 

Thanks for all the input! I figured they'd be fine, but I wanted to be sure.

Again, thanks!