K9pal

We have a Master Spa LSI557 that has developed a slow leak. We are hoping we can fix this ourselves and save an expensive service call, since we are planning to put it up for sale. The leak is in a junction of two hoses, right next to the filter housing. It leaks only when the pump is circulating. I am attaching a photo - the leak is right above the black marks. Photo is taken from the bottom looking up to the edge of the spa. We also are unclear about removing the foam insulation around the hoses to get to the leak. If anyone has any advice, it would be much appreciated. Thanks!

Thanks for both replies. So far, we have not lost additional water. I have the whole thing shut down right now, with filters removed, until I figure out what to do. I'm inclined to do as you both say, bite the bullet and buy all new filters. The Stop Leak did require that all filters be removed, then reinstalled afterwards (which I did). If I drain and refill, do I need to use anything to clean the pipes out (Spa System Flush maybe?) Or do you think just a complete drain will do it?

Please excuse the long post, but I wanted to include the background of our problem. We have a 2003 Master Spa, never had a problem til now. In September while we were out of town, winds from Hurricane Ike blew the cover off our spa and filled it with leaves. When we returned we had to completely drain and clean out tons of leaves, and since the circ pumps had continued to run, we had to replace the filters that were full of shredded leaves. Shortly after that, we realized we had a slow leak (about 1/2" every 2 days). We couldn't locate it, and I used a bottle of Spa Stop Leak. No further leaking. Cold weather set in, and we haven't been using the spa for several weeks. Last week I went out to check it, and it had shut down. The messages were HEATER DRY / SERVICE REQ'D so we called the repair guy. He came 2 days ago, tested it, reset it, primed it, removed the filters and it once again began to work. Once the water heated, we replaced the filters as he told us to do. Next morning, had the same HEATER DRY problem again. When I removed the filters this time, I realized they are gummed up with the Spa Stop Leak. Water is also cloudy, so I assume the stuff is in the water. Once the filters are out, the spa resumes normal operation so I know it's the filters that are the problem now. So, my questions are - can I clean this stuff out of the filters (since they're only 3 months old) or should we order new ones? And should we completely drain and refill the spa to get rid of the gummy stuff? Anything else we should do? Thanks for any advice and help!