I have an early 2000's Great Lakes Ontario spa. I just got this hot tub from my parents. It seemed to filter fine when I first started running it. I have since replaced the filter but am still having the problem. Under the cartridge, I see the pipe coming from the main drain. Then there is a small gap and then a 90 that has a spring loaded check valve in it. This is the pipe the cartridge sits on as well as the feed line for the pump. I assume that check valve is supposed to stay closed unless the water level of the spa drops far enough that it can no longer get water from the skimmer basket. However this valve opens immediately when the pump is turned on. The filter seems to pick up most debris on the normal cycle speed, but when the jets are turned on high, a bunch of debris gets shot into the tub, I assume through that open check valve. Any ideas?
