It’s really pretty amazing to us how many hobbyists out there are unaware that most major aquarium manufacturers name their products by market accepted standard sizes, rather than by actual capacity. This practice is very much like your local lumber yard or hardware store calling a piece of wood that is 1.5″ thick and 3.5″ wide, a 2-by-4. How do we really know the true capacity of our fish tanks then? How can we accurately figure this out? It’s really very simple. Here we have the basic formula for determining the actual capacity of a square or rectangular aquarium:

Length x Width x Height / 231

All measurements used should be in inches, and the result will be in U.S. gallons. To accurately measure the true capacity of an aquarium, it is crucial that only inside measurements be taken.

We observe that the common 55 gallon fish tank measures approximately 47.5″ long, 12″ wide and 19″ high (again, all of these are inside dimensions). When we imput these numbers into our formula, we will find that the maximum capacity of the fish tank is actually less than 47 gallons. After adding a couple of inches or so of gravel at the bottom, not filling the fish tank quite up to the top rim and then tossing in a couple of pounds of decorative rock could easily drop the water volume in that 55 gallon aquarium to less than 40 gallons.

So how do the aquarium manufacturers come up with their figures? Generally, they will use the same formula that we use, but start with outside dimensions, including the decorative frame. So by their standards, that same 55 gallon fish tank measures approximately 48.25″ x 12.75″ x 21″, for a total imaginary capacity of just under 56 gallons.

All major aquarium manufacturers appear to have been using these nominal sizes for decades, and we’re sure each one would claim that their competitors have forced them into continued use of these exaggerated figures. Just think about it, who would buy a 47 gallon fish tank from brand “A” if they could get a 55 gallon fish tank from brand “B” for the same price, even if they were advertised as having exactly the same overall dimensions? And for the most part, as far as marketing is concerned, it really doesn’t matter. Just as long as a 55 gallon tank is bigger than a 45 gallon tank, is bigger than a 40 gallon tank and so on.

Keep in mind though, there are some instances when it is extremely important to know exactly how much water is really in your fish tank. Two instances that quickly come to mind: how many fish can I safely put in my new aquarium, and how large of a dosage should I use when medication needs to be added? After all, treating 40 gallons of water as if it were 55 gallons of water, then adding a little extra for good measure could very easily result in an accidental overdose that could harm or kill your prized fish.

This formula can also be successfully used if you should come across a custom built aquarium and are unsure of it’s capacity, or if you are considering building a fish tank yourself. Tank capacity and then overall full weight can be calculated easily.

Author Bio: Steven Sannan is currently a member of the http://www.tropicalfishtreasure.com Cialis staff, with 35+ years of fishkeeping experience. Experience that includes extensive freshwater, saltwater and pond keeping knowledge.

Category: Pets
Keywords: pets,fish,tropical fish,aquarium maintenance articles