Hyperflow Design flaw?

I got myself the Hyperflow and after the initial gear excitement faded (still impressed by its weight and speed though), I started noticing something that bothers me quite a bit about this filter. The Hyperflow is composed of a top (which hold the actual filter element) and bottom cylinders and they overlap each other with the bottom swallowing the top when you push them against each other. The bottom cylinder is the one that holds all the water that will be filtered through the top filter element.

Filtering the water I've noticed that the rubber ring (to prevent leakage) attached to the piston is filled with grease and that same grease smothers the entire bottom (where the water is held) when you pump the filter, thus contaminating the water with that same grease. Either that or the grease will make it's way to the filter cutting down on it's life span. it's a long explanation but it becomes clear once you see it. Is that a design flaw?

I took out the whole filter apart and cleaned the rubber ring and the bottom cylinder that was greasy on the inside and now the pump doesn't work as easily.... :-( I will still keep the filter now that the rubber ring is clean but I can it see it wearing out faster...

Both my Pur Hiker and my MSR Miniworks have pump parts with O-rings that need to be lubricated to work properly. The lubricant is a silicone that isn't water soluble, and isn't toxic anyway. If it bothers you, you may lube the O-ring with chapstick, but the lubricant won't last as long and may eventually eat the O-ring.

Bottom line, I don't worry about the lubricant on the O-ring. YMMV.

The "grease" you are referring to is (or should be) a food-grade silicon lubricant used to keep the O-ring seal from wearing out and to improve the seal. This lubricant is used on many water filters including the MSR Sweetwater that I use. It is not water-soluble, is tasteless and should be left where it is; the system will not work as well, or as long, without it.

Well, I guess the next obvious question is, "Where can one get the replacement lubricant?"

This is probably a lifetime supply for a water filter.

Whether it's water soluble or not there is still a big chance of that getting into the water and then going into the filter. Also, since it's hollow fiber I have no doubt it willl end up in the water. I had a katadyn hiker before and though the o-ring was also greased it didn't smother the entire inside of the shell with grease and there was the carbon element to remove some of it.