The scum appears as a result of sedimentation of limy raid on inside face of teapot. The limy raid contains in water from under the crane, it does it rigid.
Adjournment of scum can lead to very adverse effects: time necessary for water boiling increases, there is probability of premature breakage of heating coil, water becomes muddy. Besides, because of scaling the teapot can be disconnected even until water boiling. For the present it is not developed any effective and reliable way of protection against scum. It should be noted that formation limyof raid happens on all heating coils, regardless of material of which they are made. At the moment producers managed to reduce the speed of adjournment of limy raid due to use gilded TENOV. Therefore, everyone should face problem of fight against scum. To clean teapot from raid it is possible to use special means.
Chemical means for de-scaling. For this purpose it is necessary to add means to water, to boil it then it is necessary to leave solution for 15-30 minutes in teapot. Then carefully to wash up it.
Folk remedies. It is possible to pour in 100 grams of vinegar in full teapot and to boil. After that to rinse water. To add citric acid to water, one tablespoon on water liter and to bring to boiling. To leave till the morning, and then to wash with flowing water teapot. Acid very well helps to clean teapot from raid. It is also possible to boil with water in teapot the washed-up potato cleanings. To repeat the procedure several times. There is opinion that it is possible to cope with this problem using the filter for water. However, it not so. Using the filter, it is possible to purify water only from heavy metals and chlorine. Therefore, need of cleaning of teapot does not disappear. It should be noted that the limy raid is harmful not only to teapot. The scum can do much harm to human health. Not to allow hit of scum in cup, it is possible to use special nylon or gilded filters. It is necessary to consider that nylon filters possess small life cycle therefore they demand periodic replacement.