Question about tank weight

My Mom and I were talking this morning, and we cant really figure out if the fish in a tank would add to the tank's overall weight. I cant really see why they wouldn't... I'm not sure though, does anyone know??

 

I think a fish would probably displace close to his own weight in water so he probably wouldn't add too much to the weight (don't quote me on that, though, it's just a guess). Plus, considering how much water, glass, & stand weigh, the fishes weight would just be a small fraction of the total weight. My largest oscar weighs maybe 2 lbs at the most compared to his tank (water, decorations, tank, etc) which weighs roughly 750 lbs.

-Chelle

 

That's exactly what I thought- the fish would be close to the weight of the water that would "fill his space." How is it that you calculate the weight of your tank? Isn't it something like 10lbs per gallon (filled)? I forget cause it's been a while since I had to figure it out! :roll:

 

the water weighs 8.3452641 lbs for a gallon. for the gravel ect... I have no idea at all... you could weigh it all and see.

 

laura has a good point. though the forse of water pooring into a tank fast is almost 65 pounds a gal. though with the water still it weighs less. i saw it on discovery

 

That's why I just round it up to 10; to account for the weight of the glass, decorations, stand, etc. It may actually be a little more than that, but 10 is an easy number to work with.

-Chelle

 

it also depends on the tank size. i know my 24 gal. is way heavier then that

 

well I think I should be ok weight wise. The stand that I bought holds up to 800 pounds. So... about 650 with water and substrate. The only thing that I'm worried about is adding in live rock. They say 2 pounds of it per gallon of water. Well um... I dont think so! That might be too much for my stand to take. Maybe I'll go for half a pound per gallon... something like that. Why do reefs have to make things so complicated?!

 

fishy chick when you put in 2 pounds of live rock you'll have to take out two pounds of water
so the more rock you have in there the less water you'll have

 

I meant 10 lbs per gallon so a completely filled & decorated 24 gallon tank would weigh roughly 240 lbs.

-Chelle

 

hey I never thought of that, thanks fish addict. I guess if I didnt take out water, my tank would end up over flowing...

 

no prob

 

Anything you add should just about displace its own weight in water, water is surpringly heavy so it shouldnt cause a huge problem, though the bottom stuff (gravel sand etc.) is heavier then water so if your good with math it shouldn't be toooo hard to figure out.

 

Hi fishy_chick, I think we are confusing weight with volume and water displacement. Example: A round 5lb ball of lead will displace less water than a 5lb piece of lava rock. As a rough guess a 2lb fish will probably displace roughly 1/2 gallon of water or approximately 4 lbs. As best as I can remember I think 20lbs of pea gravel will displace about 1 1/2 gallons of water or roughly 12 lbs. Fish will most likely displace more weight by volume.