supporting a 500 gallon acrylic tank

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The actual dims are 10 feet long 3 feet front to back and 32 inches tall. Actual inside volume minus the overflow is 502 gallons. The stand will be covered, I just haven't decided with what yet. The black thing is the overflow for the sump. The glass tank on the bottom of the stand is a standard 90 gallon to give you a size perspective. I haven't made anymore progress other than buying the plywood and foam. Once I get those on and the sump all plumbed I will post some more pictures.
 
Still working on covering the stand. My original plan didn't work out the wood only comes in 3'x7' sheets and I'm not buying twice as much as I would need if it came in 4'x8' sheets. I'm now moving on to plan B.
 
If you are using foam under the tank, you should calculate the proper foam density. For an acrylic tank that has a full-contact bottom, you need VERY LOW DENSITY foam. The pink foam found at HD & Lowes is way too stiff; it would not compress at all, therefore offering no protection from an uneven or twisted stand.

Let's assume your tank is 230 gallons with a 96"x24" base. Water is about 9lbs per gallon. To make this easy, let's say the water, gravel, and a few rocks bring the average up to 10lbs/G. So the full tank is 2,300 lbs (let's leave out the tank weight)

A base of 96"x24" is 2,304 square inches. So the force on the bottom is ONLY 1lb per square inch.

Cut a piece of wood 1 square inch. Put that on a piece of pink foam and put a 1lb weight on it. It doesn't give at all. I balanced a 25lbs weight on the wood and it barely made a dent in pink foam.

The proper foam density for 1lb/sq. inch is closer to a sponge!


A similar calculation is used for car spring/shocks. If a car weighs 5,000lbs and each spring/shock doesn't budge until the force exceeds 50,000 lbs; that will be like not having shocks at all. A car manufacturer uses spring/shocks that compress about 25% when the car is idle and occupied by two adults. Then when the car hits a bump (uneven stand) or the car goes sideways over a speed bump (twisted stand) the car and driver (fish) are spared the force and consequences.
 
The pad isn't really as a cushion. It's not supposed to be soft. It is there to correct SMALL imperfections in the stand.
 
The pad isn't really as a cushion. It's not supposed to be soft. It is there to correct SMALL imperfections in the stand.

True, if a nail head was sticking up on a plywood base, pink foam would crush over it because the super-high force on a small spot.

However, the biggest threat to a tank is a slightly twisted stand. This could be caused by poor construction or an uneven compression of the wood in the stand and floor (assuming it is not on concrete). If you have a perfectly straight and square metal stand on a basement floor, you need nothing under the tank. However, if you are dealing with wood, you need something that can compress (~ 1/32 - 1/8") over an entire section of a tank.

Sort of like putting two pop-sickle sticks under one corner of the tank and filling it up.
 
CORVETTE;1203661; said:
whats the tank its self worth i'd love one like that

I'm not real sure, I got the tank used and paid 800 for it. If you look at some of the places the make acrylic tanks that big they are several thousand dollars.
 
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