When selecting your gravel you need to take into consideration everything that is going into your tank. High water flow angled downwards can cause a problem with tiny gravel. For ground walkers and snails small gravel may be the better choice. Plecostomus will love to munch on large pieces of gravel as they suck off the algae and many shrimp enjoy holding the large pieces in their many hands as they eat. Plants can easily spread their roots in both sizes, and algae can sink further into large gravel. Some fish even like to burrow into small gravel!
Ultimately smaller gravel need less, but more difficult, maintenance and are favored by most creatures. If however you own only free swimming fish and cleaner shrimp large gravel may be more your style. If you have tank mates who require different gravel you can even get two smaller bags of each, getting the benefits of both.
While this is a choice of preference we still want to make sure new owners don't buy without thinking ahead. Sure green gravel can look beautiful and provide a rich background. Add in a couple plants and there's suddenly too much green. Likewise with black gravel it may be too dim if you have dark fish with few decorations. Remember the aquariums are supposed to be unique and vibrant. Try a color you don't see every day or even mix two colors together. Solid black combined with grey stones can give you a rich charcoal effect while green and pink produce an uplifting spring time vibe.
Savvy owners can even match and contrast their gravel with their fish. Everyone knows the combo of glow fish and black gravel. Dazzle your visitors by contrasting black and red fish with a lighter color. Conversely white/silver fish with dark colors can make a beautiful pairing.
If you do not want any live plants and have few scavengers, just an inch will serve your tank well. This will save you both space and money. For those tanks full of plants and various burrowing fish a 3 inch deep bed creates a more suitable environment
Product - Aqua Culture Aquarium Gravel, Neon Lavender, 5 lb
Gravel substrate, whether tiny shards or river rock pebbles, require cleaning much as decorative rocks do, except you'll use an aquarium vacuum instead of a scraper or scrubber. Dig the vacuum head deep into the gravel to capture organic waste that has filtered to the bottom. Clean about one-third of the gravel at each water change to avoid stirring up too much debris. If it's necessary to remove all of the gravel at one time to clean it, such as in the cases of severe algae blooms or cycling the tank from scratch, set aside a small amount of dirty gravel and mix it in with the cleaned gravel to restart the beneficial bacteria colony. Clean the gravel by putting it in a bucket and rinsing it under running water until it runs clear.
Why Gravel Is Need In an Aquarium - The Spruce
In some cases, the wise choice could be to not have any aquarium substrate at all. This is most common when an aquarist has many tanks and keeps a small one empty as a “hospital” tank for sick fish. It’s also common when a fish owner is keeping large fish in a tank that may be too small for them. In these cases, a no-gravel approach aids in waste removal, allowing the owner to keep things extremely clean when doing water changes.
Aquarium Gravel & Substrate | That Fish Place - That Pet Place