It sounds like you may have a pump that's beginning to fail. This will cause the low flow issues you mention. The first thing to do is determine if the pump is running when it should be. Try setting the tub on a filtration cycle. This should bring the pump onto low speed for a period of time. Check and see if the pump starts and stops, or otherwise operates in a peculiar manner. If it does not function properly, it's likely that you'll need a replacement pump assembly. If the pack isn't sending out voltage to the pump when a filtration cycle is called upon, then it would likely be an issue with the control system.
I had a similar issue with my old hot tub and I found free technical support through Spadepot and they walked me through it.
