# safely gluing PVC



## conger (Feb 2, 2008)

hello all, I have a pretty simple question, I just wanted to ask our community so I can avoid a catastrophe . My question is: once dried, does PVC primer (the purple kind) and/or cement pose a danger to the water passing through the pipes?

I've been putting together some PVC to plumb my sump/refugium, and after priming and cementing some pieces together, I noticed that inside the pipes, some of the primer has run. Plus, after applying cement and pressing the pipes/fittings together, some of the primer/cement mixture is exposed inside the pipe (it "bunches up" as the pipe is slid inside the fitting/socket, also if the pipe doesn't go 100% into a socket, then a sliver of cement or primer will be exposed).

I know better than to just slobber loads of cement and primer on the PVC, but even being what I thought was conservative with how much I used, it seems impossible to keep the primer and cement completely hidden/obscured inside the piping.

I just wanted to double-check to be sure it will be OK for passing aquarium water through it once the primer and cement dries, before I connect it up to my tank and poison all the inhabitants  Thanks!


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## Dave66 (Mar 26, 2008)

First thing, you should use Teflon tape on the threads of the PVC to keep the joints water-tight. instead of slathering on so much cleaner and cement. Second, you should plumb in a flow meter, because over time bacterial gunk inside the pipes will restrict the flow. You need to know when this happens, as unchecked it can burn out pumps. Third, you'll need to plumb your sump where you can take it apart when need be for maintenance.
The tape will mean you'll use much less cleaner and cement. When cured, the cement is non-toxic. I've never heard of the purple flux being toxic, but I'd be sparing with it just in case, since water is the universal solvent.

Dave


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