Hello david41139,
This is a sign the spray face is getting clogged or slowed by water deposits. When this happens it will slow the water going through the venturi in the head and begin to express water in the areas it would normally draw in air. The first thing to try is to soak the spray face in CLR. Follow the instructions on the container for use of the CLR. It will most likely instruct you to dilute. Then rinse the head well. Reconnect the head and run water through it. While running you will need to rub the rubber water channels in the spray face. Then repeat the process at least two more times to remove all the deposits. If you need any further assistance give me a call at 1-800-334-0455. Press 2 for tech and ask for David. I will be happy to help.
undo the nut that holds the shower head on ( bit behind the ball) and inside there is either a rubber washer or a fiber washer
replace that and do it up
If you are using water in another part of the house most times the pressure at the bathroom shower will go low. For instance if some one in the kitchen draws water in the kitchen sink this will make the shower water even turn cooler because of low pressure. Flushing the toilet will also do the same.
Most houses are plumbed with half inch water pipe and would work a lot better if it was three quarter inch to give more water pressure.
Easiest is to simply pour some CLR cleaner (from grocery or hardware store, it is a brand name) into a plastic bag, and tie the bag around the pipe with the shower head soaking in the solution.
Easy fix!