Aquarium Gravel Size

rainbow gravelAquarium gravel size and type matters. Let’s face it most people setting up freshwater aquariums, just pick the gravel on the shelf at the pet store, no matter how ugly it might be. This author prefers natural gravel, also available in the fish supplies area at the local pet store or fish shop. In the end, they all will work for biological filtration. Bacteria usually aren’t picky where they live. The nitrogen cycle produced when the bacteria multiply are vital to a healthy and stable environment for your fish. However, certain gravel sizes and types do better for certain situations than others. For example; goldfish create such large amounts of waste that it is usually better to have a larger size of gravel. Small fine gravel would start to clog and therefore suffocate the beneficial bacteria. Where larger gravel has more natural gravelsurface area and with modest maintenance is less likely to clog.

If there are live plants in the aquarium then it is widely accepted that a finer sand substrate mixed with small to medium gravel works well for roots to grow and routine aquarium maintenance. Some times it’s the fish that you want to keep that will determine the type and size of the substrate. If you have fish that like to dig and burrow, it’s wise to use a smaller substrate so that the fish can do what comes naturally to them without harming themselves or becoming stressed because they aren’t able to change their environment to suit their needs. If your keeping cichlids you can use crushed coral or even Arogonite because they typically do very well in tanks with a bit higher pH.

crushed coralIf it’s a saltwater aquarium that you are enjoying then the choices are crushed coral, Arogonite, or live sand if it’s a reef. Though many people subscribe to the use of Arogonite, crushed coral is able to keep the pH stable and is natural. Crushed coral that has been in saltwater tanks for upwards of twenty years—that’s right twenty—is still keeping a stable pH and healthy thriving fish. No, the fish aren’t that old, but the substrate is. In the last eight to ten years, longer in some parts of the country, the trend has been to use “live” sand in saltwater and reef aquariums. It usually looks good for a while but tends to clog easily even with minimal cleaning with a gravel siphon. Little industry secret: the “live” sand from Fiji, Philippines, or any other foreign country is nearly always children’s Play Sand from Home Depot. It’s TRUE! The wholesalers bring in Play Sand by the pallet and put it into the sand sumps that are part of their enormous filtration systems. After a week or less, the bacteria forms on the sand and it is now ready to sell as “live” sand. The cost to transport live sand because of the sheer weight is so cost prohibitive to be insane to actually do it. Where the country of origin comes from is anybody’s guess. The live sand that is in factory sealed bags and look professionally prepared on the shelves may be the exception.  Keep in mind that sand is also so fine that when stirred up it will travel through the tank and filter, often causing damage to impellers on pumps live sandand powerheads.

Back to the gravel, crushed coral, etc. that is need as part of the supplies fish need. Typical setups that have fake plants and decoration use approximately 2 ½ to 3 inches of substrate, especially if there is an undergravel filter in the tank. In there aren’t any decorations that have to be anchored by the substrate and no undergravel filtration employed then you can get away with closer two 2 inches or less. Many products aquarium stores and pet shops sell can be used in conjunction with gravel to help boost levels of nutrients for plants or to increase pH.

Size and type of substrates can actually help provide not only a great biological bed but it can make for happier tank inhabitants. Fish or invertebrates that like to build nests or burrow and have the proper substrate to do so will have less stress and thrive. This article is not designed to address every single question about substrates but rather help in the decisions regarding aquarium gravel size and types.

Article Name
Aquarium Gravel Size
Though it is not the most important thing to consider when setting up an aquarium, the size and type of substrate or gravel you choose can make a profound statement in your fish tank.

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