There are no negative effects in keeping the card in your breast pocket or wallet during the day. However, two important factors must be taken into account.
The first is that the card must be put in the correct way, that is with the white ring facing you.
The second point is that during the day we experience situations of stress, strong emotions, tensions, which have a very strong energy density and which reset our vibrational frequency. The quantum card will begin to increase our subtle energies from the first moment it is placed on the body, but any emotional disturbance will bring us back to a lower vibration. This problem cannot be remedied, as emotional energies cannot be blocked (and even if it could be done, it would not be a good idea to do it).
There are two precautions which however can make the card more effective during daily use on oneself. The first is repeatedly focus, during the day, our attention on the card, to “tune in” to the high frequencies it is emitting The second trick is to use a fast charge card, like The Bridge, which does not reach the maximum peaks of The Source but it is faster to reach its maximum peak and also has the effect of centering, rebalancing, rooting and purification from dense and negative energies. In fact, consider that The Source exceeds 6 million Bovis in 48 hours of charge, The Bridge instead reaches 1 million Bovis in 1 hour. The best use, in the daily context, is therefore to wear The Bridge and during the day to focus the intention on its frequency, and to drink regularly from a bottle of water energized with The Source.