Hi,

Ben thanks for the perspective. As a mechanical engineer I understand your comments. That said my intent is to determine if there is a "go no lower than" flow level for the filter. My guess is the final RPM setting on the new ECOSTAR will be between that point and the 55 GPM RPM setting for the solar array. My goal is to minimize energy usage

Perhaps the minimum filter flow rate is simply achieved by observing that the filter tank is full and water is coming out of the air bleed port at the pressure gauge?

Mark, I am planning on replacing the current Super II one HP motor "SP 3010 EEA2" with the ECOSTAR SP 3400VSP. The data points you requested are:

1. I understand "pre-coat pressure" means the filter pressure just AFTER the new DE has been applied. In my case this is 14 PSI without the solar valve open and 20 psi with the solar valve open for my current system with the Super II pump
2. It looks like there is one main drain line coming into the skimmer from which the single 2 inch suction line goes to the pump. FYI it is 25 ft from the skimmer to the Super II pump inlet. My guess is that there is one 45 deg bend and two 90 deg bends up to the pump inlet
3. It is 56 inches from the filter pressure gauge to pool water level.

Looking forward to any advice you can provide on a reasonable flow/ speed 1 rpm setting for the new ecostar when the solar array is not engaged. Since energy conservation is the goal, perhaps there is a rule of thumb re length of pump operation at lower RPM vs shorter pump operation time at higher RPM?