Change the language to hungarianMagyarChange the language to hungarian logo
Aquarium floor

Sand, gravel and the aquarium floor

If you are going to add live plants, as we suggest, you should pay special attention to the gravel used in the bottom of the tank. Its quality determines whether plants thrive or languish. Your fish are not concerned. They only require gravel without sharp edges. A few species prefer very fine "pea" gravel, about 1/4 of an inch in size, in which to burrow, searching for food, detritus, decayed animal and vegetable substances. Sand is an inappropriate material for undergravel filtration.
For plants the gravel should contain neither metals nor too much calcareous materials (i.e.lime): while calcareous gravel is not harmful, it hardens the water. Many fish do not like hard water and some plants cannot tolerate it. The calcareous nature of gravel and rocks is easily determined. Add a few drops of hydrochloric acid to a small sample. If it foams, it is calcerous.
The most commonly available gravels in the U.S. are river and colored gravels, some with a quartz base. Most will contribute little to the water in the way of minerals but are easy to clean.

Recommended materials: Not Recommended:
Coarse sand
(Quartz Gravel) (Top right) Volcanic ash
Basalt chips (Center, right) River gravel (Bottom, right)

Marble (calcareous)
Pumice (floats)
Dolomite (limestone)
Coral (calcareous)
Sea and beach sand (has a calcareous content)

Cleaning Gravel

A kitchen strainer can be used to clean gravel in smaller tanks, those to 20 gallons or so. Place two cups of gravel or sand in a strainer and rinse in running water. Larger quantities can be more easily handled by placing the gravel in a bucket, flushing away sediment and dirt with a hose.
Fill a bucket half full of gravel then turn the hose on lightly and push it to the bottom. Stir the gravel vigorously with your hands, flushing the dirty water gently over the rim (as if panning for gold), until the water flows clean. The more thorough the preliminary cleaning the fewer the problems with cloudy water later. We do not recommend cleaning fine gravel in a sink or laundry tub since it is impossible to prevent some from escaping and nothing blocks plumbing like fine gravel.

2.Gravel contains few nutrients and in Europe it is mixed with fertilizer to create an effective substrate for plant. This can be done in several ways if you can find the proper materials. They may not always be available, but this is the approach:
Place a layer of coarse, unwashed gravel along the bottom of the tank about 1/2 to one inch deep (1-2 cm). The nutrients may become depleted after a year or two and should be replaced. A layer of fine, washed gravel, two inches thick (4-6 cm) should be placed on top.
Washed "pea" gravel can be mixed with a fertilizer and laid 1-1/4 inch (3 cm) thick along the tank bottom. A second layer, two inches in depth (5 cm) should be placed on top. The method is excellent for a new tank but difficult with an established one. In our opinion this system has enough value that you may even wish to try it on an established set up.

Ready-made substrates with added fertilizers are also available in some areas. This ready-to-use substrate should be mixed with washed gravel and spread evenly over the tank bottom. It is easiest when setting up an aquarium.

In an established tank the only method is to add fertilizer to the gravel bed. You can use round, dried loam pellets, pressed into the substrate in two or four inch diameter centers. These can be made at home from rich garden loam, formed and dried in an oven at a medium temperature (350° F) for one hour.
The time spent preparing the substrate will pay handsome dividends in luxurious plant growth.

Laying out the substrate
It is not easy to contour the gravel in the bottom of the tank. If it is level it will be monotonous. If it is lower at the front and higher in the back, to help plants spread their roots (as it should be when plants are grown in the back) the fish will soon rearrange it. Rear terracing is best but can be achieved only with help — by using long flat stones, glass strips, petrified wood, or bog-wood and artificial plastic roots to hold the gravel in place