Just want to put added emphasis on these darn discountfilter filters and how damn fragile they are. When posters say not to over tighten that's an understatement. I tightened mine less than one revolution past finger tight and the housing still cracked! It's odd because the plastic (acrylic) is beefy where the threads are located.
When I was doing the salt water thing I would have to tighten the filter housings (RO/DI unit) substantially more than these pentek (sp) filters after changing a DI filter out.
Use caution! I wouldn't tighten much past 1/2 revolution after finger tight (seriously).
Hope this helps...