For other uses, see Gravel (disambiguation). Gravel (largest fragment in this photo is about 4 cm) A gravel road in Terre Haute, Indiana Gravel being unloaded from a barge Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel is categorized by the Udden-Wentworth scale into granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2 to 2.5 in). One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 pounds). Gravel is an important commercial product, with a number of applications. Many roadways are surfaced with gravel, especially in rural areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over 400,000 km (250,000 mi) of gravel roads.[1] Both sand and small gravel are also important for the manufacture of concrete.

Large gravel deposits are a common geological feature, being formed as a result of the weathering and erosion of rocks. The action of rivers and waves tends to pile up gravel in large accumulations. This can sometimes result in gravel becoming compacted and concreted into the sedimentary rock called conglomerate. Where natural gravel deposits are insufficient for human purposes, gravel is often produced by quarrying and crushing hard-wearing rocks, such as sandstone, limestone, or basalt. Quarries where gravel is extracted are known as gravel pits. Southern England possesses particularly large concentrations of them due to the widespread deposition of gravel in the region during the Ice Ages. As of 2006, the United States is the world's leading producer and consumer of gravel. The word gravel comes from the Breton language. In Breton, "grav" means coast. Adding the "-el" suffix in Breton denotes the component parts of something larger. Thus "gravel" means the small stones which make up such a beach on the coast.

Many dictionaries ignore the Breton language, citing Old French gravele[4] or gravelle. Gravel often has the meaning a mixture of different size pieces of stone mixed with sand and possibly some clay. American English also allows small stones without sand mixed in also known as crushed stone. Gravel with stones sized roughly between 5 and 15 mm Sand and gravel separator in a gravel pit in Brandenburg (eastern Germany) In locales where gravelly soil is predominant, plant life is generally more sparse.[9] This outcome derives from the inferior ability of gravels to retain moisture, as well as the corresponding paucity of mineral nutrients, since finer soils that contain such minerals are present in smaller amounts. ^ Mineral Commodity Summaries 2006 2009 ^ Industrial Sand And Gravel (Silica): World Production, By Country 2009 ^ Collins English Dictionary – Complete & Unabridged 11th Edition. ^ Oxford English DictionaryNoah Webster's 1828 American Dictionary of the English Language.

/d/word/gravel (8 January 2015)eds Emily Monosson and C. Cleveland. National Council for Science and the Environment Archived 8 June 2013 at the Wayback Machine.. Media related to Gravel at Wikimedia CommonsThis article is the first in our new series where we will look at the elements of hardscaping in an aquascape in greater detail. fish tanks for sale kent ukIn part 1 we will look at types of aquascaping sand and gravel commonly used today, techniques and tools used, and finally how the visual relationship works between sand and gravel, wood, and rocks.cheap aquarium light bulbs Where we have previously talked about aquarium substrates and fertilizers, in this article we will look at how sand and gravel are used in aquascaping and how they play an important role in the final aquascape piece.fish tanks for sale tewkesbury

In an aquascape the art is in creating a piece that is inspired by, and replicating nature. Aquascaping sand and gravel are graded by size and positioned in the aquarium to emulate scenes found in nature. Homogeneity, ‘composition from like parts, elements, or characteristics’ is a very popular and visually appealing aspect of an aquascape. fish tank sump pump sizeWhen similar rocks, stones and gravels are used together, the scene is brought together and becomes whole. fish tank pump loudThis gives the design the feel of the Nature Aquarium that Amano found so appealing.fish tank fish photos With the planted aquascape, the choice of sand and gravel take on another role; that of plant support. Not just visual, but practical.

The word substrate refers to the material you choose to use on the bottom of your planted aquarium. It is really important to research your substrate choice carefully as it not only is an aesthetic choice, but one which will affect the water’s chemistry, filtration, and the well-being of the aquarium’s fish, shrimp, and any other inhabitants. One of the most important issues to consider is: will your aquarium be fresh water or salt water. This is a kind of clay gravel. It is lightweight and does not compact as easily as other substrates. Fluorite can be easily mixed with sand or gravel to create a great natural look. One of the best features of a fluorite in your tank is that it never needs to be replaced. When using for the first time, make sure you have rinsed it thoroughly to wash away all of the dust. This is one of the best quality options available. Eco-complete contains more than 25 essential nutrients to support plant growth. It also contains live beneficial bacteria that are released into your tank to assist with the nitrogen cycle.

Eco-complete is also a great choice as it comes in a variety of colours. This is a very popular choice for use in aquascaping as it gives a very natural appearance to your aquarium. Aqua soil is also popular as it can be used as the sole substrate in your tank, or matched with a base layer of sand, such as the ADA Power Sand, providing biological filtration. Similarly to Eco-Complete, aqua soil is available in a variety of colours and contains long-lasting nutrition for plants. ADA Aqua Soil is a very popular brand. It is designed to be a very simple product to use; you just pour it into the aquarium and plant straight into it. ADA Power Sand is a volcanic pumice. It stops compaction and encourages water movement within the substrate helping to keep it fresh. This can be a tricky substrate to use in an aquascape. It needs to be worked with carefully to ensure it stays submerged. This substrate is great as it comes in a wide variety of colours and grades, but you will need to add fertilisers for your plants.

Small gravel is the best for strong root growth. When planning a planted aquascape, slopes have a big part to play in the texture and visual dynamics of the finished piece of art. Aquarium fashions used to be for flat substrate. Now, especially following in the footsteps of Takashi Amano, the trend is for great slopes and sweeping changes of gradient in aquascapes. This creates the illusion of depth and movement within your aquarium. Why create slopes in the substrate? To create scale and depth! The limited space afforded in an aquarium means that designs need to be creative for those displays to really shine. A decent depth of substrate also allows for your statement pieces of rock or wood to have a great support, and stem planting will root much more quickly and easily when it has a deep substrate to root in. One consideration to bear in mind is that shrimp have a tendency to move the substrate around as they clean it. If you were to just leave the aquascape then, in time, the slope may flatten out.

Just make sure you are keeping an eye out for subsidence and rake any moved substrate back to its original location as soon as you notice movement. If you have planted your aquarium quite heavily, then even with the most active of shrimps, the plants should root quickly and you shouldn’t have any issues. When planning your aquascape, remember that it is rocks as well as plants that maintain the slope. ADA sell tools for this. A rule of thumb when laying out a sloped aquascape is: level the substrate, add hardscaping items (large rocks or wood), add additional substrate between and behind the large pieces, and plant heavily. There is nothing more exciting than beginning a new aquascape. There are a few tools that will make the tasks and fiddly bits a little easier. These are a versatile tool that you will find yourself using for many tasks; planting, lifting pieces that you have dropped in the aquarium (we all do it!), and many more. There are tongs on the market that are designed to float.

While this seems like a great idea, a pair of stainless steel ones won’t rust! Specialized aquatic scissors have a brilliant design feature; they have a curve in the handle that means you can look from the outside of the aquarium while you are cutting. This will really assist you with precision cutting. Again, as with the tongs, don’t be tempted by floating scissors: buy stainless! These are a real multi-purpose tool when it comes to aquascaping. Those times when you just can’t quite reach with your hand, or the tongs are not the tool for the job, there are tweezers. Stainless steel, of course. If you are looking to achieve that flat and immaculate look with your aquarium substrate, an aqua sand flattener is an absolute essential piece of kit in the aquascaper’s tool bag. It is used to distribute the top level of substrate cleanly and evenly. This tool makes changes in the layout and maintenance very easy. As we have discussed in length above, the choice of sands and gravels will really help to create the illusion of space and movement.

Think of a mountain scene in nature. How do you know where the side of the mountain takes a break and a path cuts through? Quite often you know there is a path because of a change of colour or another visual element in the scene. To really draw the eye to, for example, the path in a mountain scene, consider using a completely different colour substrate. This will almost force the viewer to see the scene as you imagined it. In an aquascape, particularly a Nature Aquarium, you are not looking to create visual tension in your composition. In the aquascaping world, it is generally acknowledged that an aquarium featuring wood as its main feature should not then also make a feature of rocks. Sometimes less is more, and this is true when it comes to feature pieces in your aquascape. When you are working on a rock formation piece, do make sure you have carefully considered how rock formations appear in nature. The change from the very largest rock to the smallest is not instant. Large rocks chip away to smaller pieces and then from large stones to smaller stones and then to gravel.