maybe the wand is worn out? the wands need to have some restance to flow in order make even bubbles, and that wears out. If you are powering more than 1 thing you should be sure to use a gang valve. I have a tetra whisper 60, it powers two 3" wands and two stones at 18" deep. but if I dont use a gang valve to regulate and restrict the flow to each stone than air only goes to the first wand sence it is the easiest route, and no air goes to the other stones. I guess I would recomend the tetra whisper for the price but get the 100, its only a few bucks more. I would not say the tetra is any louder than any other pump, but it is definately not a silent as the advertising on the box implies.