Plumbers putty

[FSM]

if it's safe to use for drinking water (it probably says on the container, PVC cement does) it's safe to use for fish.

 

[koop171]

I've used the teflon putty one some plumbing before it worked great.

 

[Karlos]

some of the ABS (black plastic) threaded cleanouts have O rings already on them so you wouldn't need to re-tape the threads everytime. Or maybe one of these. just a srewdriver is needed to loosen the nut

 

[johns]

"plumbers putty" is not used for potable water systems, and has oil in it. Hope You mean pipe dope, or thread sealant. Use Teflon tape as Zennzo described. Just watch which way You wrap it.

 

[sirdavidofdiscus]

I used silicone. It has been running for 3 wks without any trouble.

 

[lpenn31]

i just used the putty on my filter hope it doesnt kill fish

 

[Clay]

The answer is yes, plumbers putty is safe for fish and potable water. Teflon tape will work probably, teflon paste definitely, silicone isn't meant for plastic.