Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I use them (unions) for my sumps, and for my pond. I do not take them apart very often, maybe once a year, if that. The only problem I have is if there is any strain on the pipes so they are not lined up well. Then it can be a bit of work getting the union back together.
Any disconnect will leak a bit, so this system is not better or worse in that way. Just have a towel handy, just like when you take apart any other plumbing fixture.