HP9000s Heat question

[Kyrin7]

In our shop, we've noticed, that at the factory set heat, @45 degrees, the Cyan ink tends to start to clog after about a half hour of printing or so. After some extensive testing we've gotten a good range, 2 35 degrees.

My question is, does anyone know what the minimum suggested per media is, or at least what you've had success with?

Thanks in advance.