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).
Are you talking about the actual housing or the 3/4 inch inlet/outlet. I just did the housing hand tight, and it was the only connection that didn't leak haha. Everything else I tightened as tight as I could get it with channel locks. I was first scared to strip the threads so I didn't tighten them as hard as I could. I wish I did because it got leaks in several spots and had to retighten them.
I wanted to give an update, I turned my co2 up more and now got a yellow drop checker, I reduced co2 slightly and increased surface agitation but today the drop checker is still yellow, fish arn't gasping so I'm rollen with it. I hope it helps my algae problems.
Hope this helps...