Yagyas for Planets

Planetary Yagyas are to neutralise the negative influences and strengthen the positive influences of the lords of the Mahadasha, Antardasha, Pratyantardasha and transits (Gochar). If a particular planet in its Mahadasha, Antardasha or Gochar is adversely affecting a particular area of life, it’s Yagya is performed to bring favourable planetary support and reduce the negative influences of that planet. 
The malefic actions of significant planetary influences has traditionally been regarded as one of the prime causes for lack of success and disharmony with in the home. Sri Yagya is performed to strengthen what ever planetary imbalances may be prevailing in one's birth chart

Shani Sarhesati is a 7.5 years terms while Saturn transits through your 12th, 1st and 2nd house from your Moonsign. It depends on your horoscope whether it will be good for you or bad but in both the cases, it is difficult and tough period. Getting our of thsi, even in good position is very difficult. In fact in this period, man thinks he is doing right while he is doing wrong. The another character of Sarhesati is that whatever it geives in beginning, take back at the end. It means if you are getting money in the beginning of Sarhesati it will certainly take all back with perhaps your past capital. But if you are poor in the beginning then it will leave a cause to be wealthy at the end. The most important is that the 3rd round of Sarhesati kills the person in 95% cases. A sarhesati returns after 27 years. Doing Yagya for Saturn helps kaaping balance and protectionfrom risks and dangers.

Kaal Sarpa Dosha

When all your planet accupy the houses between Rahu & Ketu then it is afflicted by this Shadow planets who bring dark in your life. Kaal is the name of Rahu and Sarpa is Ketu. therefore it is called Kaalsarpa yoga. Kaalsarpa yoga basically limits your successes and opportunities. It doesn't let you come across the opportunities by which you can rise. It is worse then Sarhesari as Sarhesati works for 7.5 years but Kaalsarpa works for whole life.