eshopp pf-1000 HOB minimum flow rate

[Full Metal Albacore]

So I have been looking at getting an eshopp pf-1000 HOB for my 100 gallon tank. Drilling is not an option. From what I understand to keep bubbles out of the U-pipe you need to have a high enough flow rate. I can not find any info on what the required flow rate is for the pf-1000. I am currently getting 800-900 gph from my jebao dcp-5000. I plan on improving this by switching from the ribbed pond hosing I am currently using for my return to hard plumbing. There is about 3 feet of vertical distance between the water level of my pump and the top of my tank, there will be about 2.5 feet of horizontal piping and I will have 2 90 degree elbows. All of this plumbing will be 1 1/4" pvc. I imagine with that hard plumbing my output from my return pump will increase but I would still like to know what the minimum flow rate for the pf-1000 is. Would my current flow rate of approximately 850gph be sufficient or would I have bubble build up?

 

[blaxsun]

The maximum flow rate is 1000Gph, so i'm assuming that the minimum would be substantially less.