Ummmm!!!...Didn't think I mentioned anything about connecting the PA2 to AQ4 or that they communicated with each other?....... I just pointed out (as you have just said) that the PA2 will work with the AQ4, It shows up fine in the Aquasuite software as a seperate item yes, But it does run with the AQ4..... I had one running with my AQ4 for well over a 12 month's before I upgraded to the AQ5

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Sorry if what I said in my previous post was misunderstood....
N.