Hi all. Have had my spa for about a year. Everything is going fairly good but always looking to optimize. Typically all I do is add 0.5 ounce of dichlor every other day. My levels are always great. And anytime Ph starts dipping I will raise it with spa up and then alkalinity and ph get back in line. At about 3 months I dump the water and start over. My water is usually always clear and crisp looking and when(if) it gets cloudy I would just shock. Cya level getting way up there and I wanted to get another month on this batch of water so I tried MPS and shocked with 1.5 ounces. Went in spa the next day and I’m getting these wierd gunky bubbles that cling to side of tube, never get scum line using just dichlor. Is this scum just oxidized material and should I just shock with dichlor as well to clear it so it stops coming back? Water looks great and levels are all in line but don’t want this gunk in my tub.