It all depends on the "bio-load" of your tank - Bio-Load is the waste created by the fish and waste removed by the good bacteria in your filter.
If there is only a small amount of fish producing waste you should be safe with a fortnightly gravel vac
If there is a heavy bio-load (10-15 fish) you should be doing part water changes and vacs weekly.
All depends on what waste is produced and removed.
It depends. If you are not using an undergravel filter, then 1.5-2 inches of gravel is sufficient. For a 55 gallon aquarium, 1.5-2 inches is 60-75 pounds of gravel. If you are using an undergravel filter, the recommended height is 2-4 inches (75-100 pounds of gravel). Also, it is best to use gravel that is 2-3 times the size of a pinhead. Do not, however, use fine sand in an aquarium that has an undergravel filter.
"You need enough to make the gravel at least 3 inches deep at the back and slope down to about 1 inch deep at the front".
That's not an answer. For live plants you want about 80 pounds. Without plants any amount is fine unless you are still using under gravel filters. Then you can get by with 50 pounds. Assuming this is a standard 48" long 75 gallon tank.
I would put in 5-11 bags of sand to cover the bottom of the tank. With gravel you could manage to put in less make sure you get the cheapest price cause your gonna need a lot of it.
a good rule is to use a pound of substrate per gallon of water in any aquarium
40 lbs will do.
You need at least 10 lbs of gravel
No, but gravel can help decorate and brighten an aquarium.
For a fish tank, you need enough gravel to make a thin layer on the bottom of the aquarium. For an outdoor walkway, you need much more.
Air bubbles will do nothing. What is needed is a filter.
I would think at least a 60 gallon aquarium
An aquarium, if you want plants, depending on the type you may need substrate, a filter, sand or gravel about 1 pound per gallon, a light between 5000K and 6500K (it does not have to say aquarium), water purifier, water, fish food, a power strip that has at least 4 outlets, an aquarium heater if you are going to have tropical fish. and about 30 minutes to put everything together and add water
I wouldn't advise it but I suppose it is plausible.
10 gallon if its only 2 inches and a 20 gallon for 4 inches
1 square km of gravel
you need more neighbor i guess, maybe you can try this site, is all about happy aquariums.http://www.yayeasy.com/
1 cement 2 sand 3 gravel
Most people keep snakes in an aquarium with a very secure lid. The bottom of the aquarium will have sand or gravel and something for the snake to climb on or hide under. A warming light is also a good idea.
You will need 0.309 cubic yards (about 600 pounds) of gravel.