Coverage depends on various factors. There are a number of different causes that can influence the calculation: the porosity of the surface, the age and the composition of the concrete, and the atmospheric conditions at the time the stain is being applied.
 
Porosity influences the area that can be covered because a flatter, smoother surface will absorb less stain than a porous surface, hence less than 5 liters of StainColor could be used to cover about 30m2.
 
The age of the concrete is important, since, through wear, a surface that is 60 years old for example might not have the minerals that are needed to react with the acid stain. Normal erosion with the passage of time may leave the surface without the necessary minerals; this is more likely for an exterior surface that has been exposed to the ravages of time.
 
The composition of the concrete is important because, as has been explained, some concrete surfaces might have more minerals than are necessary for the acid coloring; some might not have the right minerals and/or they might be present in very low concentrations; while some concrete surfaces contains polymers (plastic) which are used to harden concrete, and thus reduce the StainColor coverage.
Finally, the time is also an important factor, because concrete expands with heat. It will therefore be far more porous when the temperature is high, with the result that the acid stain will be absorbed faster than if it were applied when the temperature is cooler.
These are all situations that can influence the coverage of the acid StainColors, and hence it is not possible to state precisely how much stain is necessary, since every case is different.
However, as a general rule an area of about 30m2 can be covered with 5 liters of StainColor. Furthermore, as mentioned in the “Use” section of these instructions, if the shade of the stain is too dark, it is possible to dilute it with water. It is recommended not to dilute it by more than 30%, but it is obvious that if a gallon of stain is diluted with 20% water, the meters covered will increase by 20%.

EQUIPMENT:
 
The most important equipment of all is the safety clothing. Users are advised always to wear safety clothing since these acid stains carry a health hazard.
 
Cleaning before and after requires the following utensils: a bucket, a neutral detergent, a floor cleaner, a broom and lots of cold water. An acid-proof receptacle can facilitate the process of preparation and cleaning. If such a receptacle cannot be used, use paper towels, sawdust or old rags to absorb the excess. If the surface is already covered by a layer of some sort, it might be necessary to use a sander and/or monobrush to remove it.

Application of the stain requires brushes, sponges, rollers, merino wool applicators and/or a hand pump sprayer, and an acid-resistant plastic bucket. Do not use brushes that have colored bristles because the acid StainColor could change color. Hand sprayers can be bought at any hardware store; they are usually used to spray insecticide on plants. They must be completely made of plastic, because the acid solution will corrode any metal parts!