Can 8x8x8 stone blocks (grey and hollow,) hold up a full 55 gallon fish tank?

Question

I want to make a two foot high shelf for my aquarium. The tank is 48"x20"x14" (length,height,depth). Blocks with be stacks of 3 high, 3 stacks across, covered by redwood planks. The stone blocks are the kind used in construction. It will be in my patio, under a partly covered overhang. Will the blocks crumble over time under the weight of the tank, which i heard will be 600 lbs when full? Will it hold up in a small earthquake? Will the redwood planks give way over time due to being outdoors and subject to a little splash or drip of water occassionally?

Yes, that's it, cinder blocks.

Answer 1

A 55 gal. tank when full of water should weigh about 470 lbs. (taken at 8.5 lbs./gal.). I think 2 blocks could hold this, but I would make sure to put them face down ... if you put them sideways, they could crumble more easily.

I need to modify my answer. You want to go 3 high, and you are using redwood planks? I would arrange the blocks 2 deep, with 16" wide planks... use 3 pairs of blocks, spaced across the 48". I think you'll be okay, assuming you have the tank flushed up against a wall in the back.

Answer 2

Yes they should hold the fine. Water weights approximately 8 pounds per gallon, 8 x 55= 440 lbs not including gravel, rocks and stuff so 600 lbs is a good estimate. The blocks and planks should hold indefinitely. You may want to stain the redwood so it doesn't warp from the water. I won't comment on the earthquakes as that's a very subjective question. If the aquarium is going to be outdoors, i'd be concerned with algae. Algae will be very hard to control in direct sunlight. You may be able to manage if you work with it and just accept the algae as part of the decor. I think algae promotes oxygenation and can be a filtration system in itself. Algae can also clog and degrade mechanical filters increasing maintenance time. good luck to ya, /r

//I'd stand the blocks on end so the columns of air are vertical. The strength of the bricks resides in the column structure, not in the material itself. It's like resting a book on a rolled newspaper.

Answer 3

yes they will be fine I have a similar set up. They will support it extremely well. Make sure the tank is supported by plank on all sides of the tank and is perfectly level. Unsupported sides and even the littlest bit of unlevel will crack the tank eventually unless it is acylic. That plastic ring around the top and bottom do nothing for support and all that actually holds a tank together is silicone. I have seen many a persons tank crack right across the bottom or up the back from being a little unlevel.

Answer 4

If you are talking about those red blocks they crumble after many years. Concrete blocks might be stronger. you could plaster and paint them for that finished look. Red wood is strong double up for added strength. Threat the wood with a sealant against the elements. You should be fine for years. If you are a fish lover you will spend enough time there any problems you will see right away.

Answer 5

that will be fine. it will be about 800lbs if you get live rock too. you might want two planks, just to be safe tho (and to make sure its level). make sure you treat the wood. you dont need it rotting, because once that tank is on it, its going to be impossible to move it while its full. (i have 2-55gal tanks)

you are talking about cinder-block, right?

Answer 6

try