There should be a short breath retention while repeating mooladhara three times mentally. Ujjayi inhalation should be synchronized with the ascent of awareness through the arohan passage. Retain the breath for a short time while mentally repeating bindu three times. Exhale with Aum sound from bindu to mooladhara through the spinal awarohan psychic passage.
Try to practise the kriya in the correct manner with alertness. It is very easy to forget parts of the practice or even do the practice without attention. Let the thoughts arise, but try to maintain awareness of the practice. If you feel sleepy take a cold wash or bath.
Remember to try to remain a witness throughout the practice.
Counting of rounds
You have to do 13 rounds. Therefore, at the end of each round you have to keep a count of the number of rounds that have been done. You should count as your awareness reaches mooladhara at the end of Aum descent in the awarohan passage. Various methods of counting can be used. Mental counting is the obvious method, but this has the drawback that it is very easy to forget. If you wish you can count on your fingers. The best method, however, is to use a mala. You should tie a knot or piece of string at the thirteenth bead past the sumeru (junction or summit) bead5. When you start the practice of nada sanchalana, hold the mala just before the first bead after the sumeru bead. Then as you complete each round, rotate the mala through one bead. When you reach the thirteenth bead you will feel the knot and know that you have completed 13 rounds. Experiment and find the method of counting that you like the best.
About 7 or 8 minutes will be required to complete 13 rounds.