Happy new year everyone. First off, I've searched and read a good number of threads on "foam issues" already, but haven't found any answers to my particular situation.
My hot tub (~450 gal, 3 step bromine) has been acting funny on me all of a sudden. It hasn't been used much lately and I did inadvertently let the sanitizer get down to almost 0 for a day or two a few weeks ago, but I've been shocking and keeping an eye on pH, TA, and so on since then.
All the chems are good now and overnight sanitizer loss is minimal (I took pucks out while shocking and doing all this testing), but when I turn the jets on high and open the venturi valves, the water almost instantly begins foaming significantly. The entire water surface will be under 4-6 inches of the fluffy white stuff within 10 minutes. The foam doesn't seem slimy or dirty, but it's there and I don't like it.
Conversely, I can put the jets on high with the venturi valves closed and not have any foam issues at all.
Can anyone offer any suggestions?