A reader asks:

My spouse and I have just received CET’s negative ion generator. We both suffer from depression, though mine is milder. When setting it up in the bedroom, should it be on his side of the bed? Do we need two in the bedroom? Or should one of us use it during the day with the wrist strap? Thanks.

Answer:

If you keep your bedroom windows and door closed, and add a humidifier, one unit should be enough. Where you put it is not critical. But you’re right, the ion concentration will always be greater for the spouse who sleeps closer to the generator. Three feet should be a fully adequate distance. Be sure not to place the unit close to other electrical devices (for example, telephone, TV, or clock radio) because these devices will reduce the number of ions around you.

If you do not improve in a couple weeks, either or both of you can try adding a 30-minute daytime session where you keep the ionizer close to you.