Zeolite gravel absorbs ammonia.
Absorbs heavy metals and nitrous compounds
1 gram of zeolite removes apporx 1.5mg of ammonia
It can be used in filters or as substrate.
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that had been adsorbed by the material. Based on this, he called the material zeolite, from the Greek (zéo), meaning "to boil" and (líthos), meaning "stone"
Zeolites have a porous structure that can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+ and others. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution. Some of the more common mineral zeolites are analcime, chabazite, clinoptilolite, heulandite, natrolite, phillipsite, and stilbite. An example mineral formula is: Na2Al2Si3O10·2H2O, the formula for natrolite.
Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater. Zeolites also crystallize in post-depositional environments over periods ranging from thousands to millions of years in shallow marine basins. Naturally occurring zeolites are rarely pure and are contaminated to varying degrees by other minerals, metals, quartz, or other zeolites. For this reason, naturally occurring zeolites are excluded from many important commercial applications where uniformity and purity are essential.
gravel or sand
How much sand do you need?
Aquarium 63 liters (60 x 30cm) -8 to 10 kg
Aquarium 112 liter (80 x 35cm) - 12 to 16 kg
Aquarium 200 liter (100 x 40cm) - 20 to 24 kg
Aquarium 240 liter (120 x 40cm) - 25 to 29 kg
Aquarium 300 liter (120 x 50cm) - 30 to 37 kg
Aquarium 375 liter (150 x 50cm) - 40 to 49 kg
Aquarium 500 liter (200 x 50cm) - 52 to 60 kg