Aquatics Unlimited: Articles: How Much Gravel?
Image 1
Image 2
Image 3

How Much Gravel?

for the week of 7/30/98

To quickly estimate the amount of freshwater gravel required for an aquarium, simply multiple the aquarium's length (in inches) by it's width (in inches), then divide by ten (whacking off the last digit will suffice). The resulting number is the number of pounds of gravel that will cover the aquarium bottom to an average depth of two inches.

For example, a standard ten gallon tank is 20 inches long by 10 inches front to back. Multiplying the two numbers gives 200, then chopping off the last zero leaves 20 pounds of gravel, which does indeed cover about 2" on the bottom. A 55 gallon would be 48 x 13 = 624; chopping off the four leaves 62 pounds. If three inches of gravel is preferred (and that would probably look better in a large tank like the 55), add half again the amount (62 x 1.5 = 93 pounds for average three inches in the 55).

The crushed coral commonly used in saltwater setups is considerably less dense, so multiplying the aquarium length and height would yield almost three inches of gravel, rather than the two inches of the quartz or granite used in freshwater. Conversely, fine silica sand, which we probably shouldn't use anyway, is denser, and our magic number would probably yield only a little over one inch.

As far as the depth of gravel required goes, anywhere from none to about 6 inches can work, and is advocated by somebody or other. In most tanks, gravel is primarily decoration, and helps support other decor items such as rocks or driftwood. For this, two to three inches is generally sufficient. Shallow gravel lacks character and supporting power, and deeper gravel is hard to keep clean. Two to three inches is often the recommended gravel depth for tanks with undergravel filters as well.


"Tip of the week" appeared regularly in 1999 and 2000.

Copyright © 1998 Aquatics Unlimited
All rights reserved.

Local Specials

Through 1-28-18

Plecostomus & Catfish 20% OFF!

Arrow Crabs 20% OFF!

Clownfish Buy 1 Get 1 Free!

Anubias 20% OFF!

Aponegeton Bulbs 20% OFF!

2.5 Gallon Tank $13

5.5 Gallon Tank $14

10 Gallon Tank $17

15 Gallon Tank $35

20 Gallon High Tank $36

20 Gallon Long Tank $36

29 Gallon Tank $56

30 Gallon Tank $66

30 Gallon Breeder Tank $75

37 Gallon Tank $76

38 Gallon Tank $82

40 Gallon Breeder Tank $95

45 Gallon Tank $107

50 Gallon Tank $151

55 Gallon Tank $117

65 Gallon Tank $159

75 Gallon Tank $148

90 Gallon Tank $255

120 Gallon Tank $414*

125 Gallon Tank $342*

150 Gallon Tank $591*

180 Gallon Tank $715*

210 Gallon Tank $808*

65 Gallon Overflow Tank $249*

75 Gallon Overflow Tank $280*

90 Gallon Overflow Tank $336*

120 Gallon Overflow Tank $556*

125 Gallon Overflow Tank $478*

150 Gallon Overflow Tank $779*

180 Gallon Overflow Tank $852*

210 Gallon Overflow Tank $953*

Select Aqueon Pine Black Stands 20% OFF!

REWARDS account may be required for special pricing. You may sign up and use the special pricing the same day!

* = SPECIAL ORDER; 100% deposit required

** = while supplies last

*** = specially marked tanks only; selection may vary during the sale

Aquatics Unlimited | 3550 S. 108th Street | Greenfield, WI 53228
Monday-Saturday 10:00 a.m. - 9:00 p.m., Sunday 10:00 a.m. - 6:00 p.m. | Phone: 414-543-2552 | Fax: 414-543-4929