My 72gal bowfront is only 62gal! where did the 10gal go??!!

[sushiray]

What fish do you have in there and how much decor? It is probably just because your fish/decor are displacing 10 gallons of water.

CUT N PASTE

OK I SHOULD REPEAT MYSELF. BARE BOTTOM DISCUS TANK. 1SPONGE FILTER 1 DECORATIVE ORNAMENT 1DRIFTWOOD 1HEATER - LET'S GIVE CREDIT WHERE CREDIT IS DUE & THIS ALL DISPLACES 1GAL - OK EVERYONE??
:wall:

FOR ADDED EFFECT:

WHEN I MEASURED MY FILLINGS IT WAS ALL BARE BARE BARE LIKE A NAKE BABE BABE BABE, NADA NOTHING NO WAY JOSE ANYTHING WAS IN THERE EXCEPT AIR AIR AIR!!
:bowing: :nilly:

 

[sushiray]

lol! Cashlaw beat me to it!

HOPE IT FEELS GOOD!

:worthy: c:

 

[PsyKick]

I think its rather a moot point except for in the realm of medication, and even then maybe not.
While it does seem to be true that we are all getting shorted a few gallons than what the tank says it holds, it does not actually effect how we interact with the tank.

For example, if person A comes to AC to find out how many tetra's they can get for their standard 55 gallon tank, the advice and experience given by the members of this community will be based on our own experiences owning and operating standard 55 gallon tanks. So even if the standard 55 gallon tank is really 40 gallons, it doesn't change what we know will work or wont work with it.

Is this false advertising? Yes
Does it really matter? Not so much
With the notable exception of Medication which is supposed to be dosed per gallon of actual water, but even here, I would guess that many medication manufacturers use tank measurements as a base for their recommended dosages...

 

[Kashta]

You need 4 measurements the way it's done in the industry to calculate the volume for bow front tanks.... length, width at the side panel, maximum width of the bow, and height. For the 72 gallon bow front (which I also own, btw), the approximate measurements (which are taken as outside glass measurements instead of the more-precise inside glass spans) are:

48 long, 12 side width, 18 bow width, and 22 height.

Since people who maintain reef tanks typically use more complex equipment setups and need more precision when making calculations (compared to us freshwater folks), this link takes you to a more accurate tank volume calculator. Note the illustrations for tank shape options and you'll see how each shape is measured. This particular calculator also lets you adjust the actual volume calculated to account for substrate depth, actual water level, use of a sump or refugarium, and so on.

Here's the link: http://reef.diesyst.com/volcalc/volcalc.html

Using this volume calculator:

1. Set dimensions to inches.

2. Set tank shape to bow front.

3. Enter figures (48, 12, 18, and 22).

4. Set volume results to US gallons.

5. Click the 'calculate' button.

The approximate volume you get is 73.3 gallons.

For a more accurate computation, take PRECISE inside dimensions including the real water level (since you're not going to keep this thing filled to the point of overflowing) and what you'd get when it's totally empty of everything but water is very very close to 72 gallons.

That's where the 72 gallon label comes from and this is totally acceptable as a standard within the industry. No one is being deceived and people who buy this tank are not being ripped off.

 

[sushiray]

LORD I SEE THE LIGHT!! HOW DO I LOVE THEE? LET ME COUNT THE WAYS!!

This article discusses why most tanks contain much less water than advertised. According to it, a standard 55 only contains 47 gallons, before gravel and deco are added.
http://www.bestfish.com/tips/052198.html

Leah, I thank you for your participation contribution & understanding. :clap:

To say the least, at least there is independent reporting & experience outside of my own. It would appear I was ranting & raving for no apparent logical reason.

As a student of math accounting the sciences - the margin of error in my actual "experiment" (mis-counted the jugs in) & calculations (not using the tape measure correctly) could not be so high as to be off by 10gal. on a 72 bow.

So Cash & Froggy - I agree, grated minds think alike. You both presented such reasonable doubt ignoring what I had written that everything was bare when I started the process that I can see how simple minds (great 80's group btw) can think alike. :bowing: :footinmouth: :duh: :thud: :frog:

thank you all & to all a good nite! :y220e: :newbie: :hi:

 

[excuzzzeme]

I have to say that you are certainly all making a mountain out of a molehill and trying to compare apples to oranges. Yes, outside measurements are often employed in the classification of a tank but so is the water level. When a 72 gallon tank is filled completely to the top, it will hold within a 5% tolerance the advertised gallons. The problem arises that we do not use 100% of the tank. Most often we use approximately 80% in a realistic application. Some people don't fill tank to the trim and are using even less. Add in substrate, decor, and fish, displacements are more pronounced. Example a 150 gallon tank may only hold 146 gallons (within 5% of advertised) and you actually use maybe 135-140 gallons!

Get a grip on reality!

 

[psyche]

Well, I filled my completely empty 3 gallon desktop tank to the very brim with 2.2 beaker-measured gallons of water. So I think misrepresentation goes from the small to the large tanks pretty routinely.

 

[Freezekougra]

Well on the bright side, we know that we are doing a bigger % water change

 

[sushiray]

You need 4 measurements the way it's done in the industry to calculate the volume for bow front tanks.... length, width at the side panel, maximum width of the bow, and height. For the 72 gallon bow front (which I also own, btw), the approximate measurements (which are taken as outside glass measurements instead of the more-precise inside glass spans) are:

48 long, 12 side width, 18 bow width, and 22 height.

Since people who maintain reef tanks typically use more complex equipment setups and need more precision when making calculations (compared to us freshwater folks), this link takes you to a more accurate tank volume calculator. Note the illustrations for tank shape options and you'll see how each shape is measured. This particular calculator also lets you adjust the actual volume calculated to account for substrate depth, actual water level, use of a sump or refugarium, and so on.

Here's the link: http://reef.diesyst.com/volcalc/volcalc.html

Using this volume calculator:

1. Set dimensions to inches.

2. Set tank shape to bow front.

3. Enter figures (48, 12, 18, and 22).

4. Set volume results to US gallons.

5. Click the 'calculate' button.

The approximate volume you get is 73.3 gallons.

For a more accurate computation, take PRECISE inside dimensions including the real water level (since you're not going to keep this thing filled to the point of overflowing) and what you'd get when it's totally empty of everything but water is very very close to 72 gallons.

That's where the 72 gallon label comes from and this is totally acceptable as a standard within the industry. No one is being deceived and people who buy this tank are not being ripped off.

thks kashta for your reference link - this is useful for BF's. BUT I AM NOT DISPUTING THE COMPUTATIONS BASED ON THE DIMENSIONS GIVEN - all the online calculators & conversions are precise & give the same results.

as for my 72gal BF I used 15" as an avg & it calculates to 68gal. close but no cigar. I accept this estimated result.

and I measured my tank outside & it is nearly the same as aqueon's product spec sheet online - outside measurement.

BUT YOU ARE IMPLYING (AS WELL AS WITH CASH & FROGGY) THAT MY ACTUAL EXPERIENCE OF FILLING UP THE TANK (AGAIN REPEAT IN A BARELESS TANK FULL OF AIR) THERE WAS A MISTAKE ON MY PART? & YOU AREN'T GONNA Q? ME ON WHETHER I HAD ANY SUBSTRATE & OTHER OBJECTS OF DISPLACEMENT LIKE THE OTHERS, ARE YOU?

SO THEN GOES THE SAME DOUBTS & DISPUTE FOR BEABROCA & D_K IN THEIR OWN EXPERIENCE OF SHORTAGE.

I AM CURIOUS IF YOU WERE TO FILL YOUR TANKS IF YOU WOULD COME TO STATED VOLUME HOLDING ALL THINGS CONSTANT - KEEPING IT ALL BARE BARE BARE ONLY AIR AIR AIR B-4 FILLING IT UP WITH A 1GAL. JUG WHICH BTW IS 1GAL +3OZS.

I AM CURIOUS TO YOURS & OTHERS REACTION OPINION COMMENT ON THE FOLLOWING LINK PROVIDED BY LEAH:

http://www.bestfish.com/tips/052198.html


PLSE ALLOW ME TO REITERATE & RE-EMPHASIZE - THE STATED VOLUME (AS POSTED FOR THESE TANKS NOT JUST MINE) APPEARS TO BE HIGHER THAN ACTUAL FILLAGE. THAT IS MY ISSUE.

 

[sushiray]

I think its rather a moot point except for in the realm of medication, and even then maybe not.
While it does seem to be true that we are all getting shorted a few gallons than what the tank says it holds, it does not actually effect how we interact with the tank.

For example, if person A comes to AC to find out how many tetra's they can get for their standard 55 gallon tank, the advice and experience given by the members of this community will be based on our own experiences owning and operating standard 55 gallon tanks. So even if the standard 55 gallon tank is really 40 gallons, it doesn't change what we know will work or wont work with it.

Is this false advertising? Yes
Does it really matter? Not so much
With the notable exception of Medication which is supposed to be dosed per gallon of actual water, but even here, I would guess that many medication manufacturers use tank measurements as a base for their recommended dosages...

AGREED. EXPERIENCE IS A GOOD THING.

MY GRIPE IS MY EXPERIENCE ON FILL UP TO SEE I CAME UP SHORT IS FOR ME BOTHERSOME. BUT YOU KNOW WHAT - OF COURSE IT DOESN'T MATTER FOR YOU FOR ME FOR THE REST OF THE GANG HERE. I LOVE MY BF I LOVE MY DISCUS I LOVE MY EXPERIENCE IN WATCHING THEM FEEDING THEM & ARGUING WITH THEM THAT THEY ARE NOT IN AN ACTUAL 72GAL BOWFRONT TANK - IT'S LESS!!

AS FOR MEDS - USERS USING SOME STRONGER MEDS WOULD WANT TO KNOW THE ACTUAL GALLONAGE THEY HAVE THAT THEY ARE TREATING (NOTING THAT WE ALL DON'T FILL TO THE RIM) - MAKES ONE WONDER WHY SOME WHO USE CERTAIN MEDS EXPERIENCE DETRIMENTAL RESULTS WHEN IN GENERAL THOSE MEDS ARE GOOD FOR THE DISEASE AT HAND. NOT TO GET INTO ANOTHER DIATRIBE OF WHETHER THEY DIAGNOSE IT CORRECTLY OR USE THE CORRECT DOSAGE OR HAD BAD PARAMETERS OR USED IT IN CONJUNCTION WITH OTHER MEDICINES OR .... I BETTER STOP HERE.