Welcome to the forum.

Not being familiar with this particular unit, I had to print out the manual to see what it looked like.

Does the "puff of white cloud" dissipate fairly quickly without affecting the clarity of the rest of the pool. If so, then it is simply generating hydrogen gas, which is a byproduct of the SWC operation.

To check if the unit is working, take a sample where the cloud comes out, and check if the Cl reading is higher than the figure you gave in the previous post. Make sure that the cell is on when you do this. If not, than the unit is not producing Cl, in which case the cell needs to be cleaned, or replaced, or you can install a brand new unit.

I personally would go with a new unit, based on what I saw from your manual. After 6 years, as you are finding out it becomes difficult to find replacements.

Check through this forum, and you will get some ideas of who likes this or that particular SWC. Then check on-line for the best prices.

Hope this helps, and the forum members are here to help you with further questions.

Pat