Android viruses from adult sites supplement for fertilizer substrates contains 35 elements, the most important in the product are - potassium, magnesium, iron, manganese, zinc, calcium, edta. essential for aquariums with solid fertilizer on the bottom. haquoss d20, the only product of its kind, contains the micro elements absorbed daily by plants, in percentages but macroscopically different, its use is essential to permanently integrate the solid fertilizer amazon base and amazon substrate present in the aquarium making it permanently active! use - the presence of iron in water is the indicator of the activity of the background fertilizer present, therefore, after one month from the preparation of the aquarium: 1 test the iron contained in the water with haquoss fe control the value must be at least 0.5 mg / l 2 if the value is correct wait another month and then repeat the test 3 If the value is less, spray haquoss d20 on the surface of the water by pressing once on the measuring cap every 25 liters of water every day for a week. 4 if the optimal value has been reached, test again after one week, otherwise repeat the operation of point 3 until reaching 0.5 mg / l. observations- the quantity and use of haquoss d20 are related to different factors such as the number and type of plants - use of co2 - type and number of lamps used and ignition time 50ml treat 1250lt of water