Sealing threaded plumbing on circulating pump

[AlexG]

I want to clarify that the solution to use silicone 1 would only be for thread to thread PVC connections (for aquarium related plumbing) and not for a union gasket seal leaks. I have been using silicone 1 for over 7 years now to seal PVC thread to thread connection with 100% success and no leaks in two different systems now. The only drawback to silicone 1 is that it must be allowed to cure 12-24hrs before water and pressure can be applied to the plumbing. Teflon tape does work but I find it is the most likely to leak with PVC threads from my experience with aquarium plumbing. The teflon paste is just a mess to work with and the few times I used it there were small pieces of it found in the aquarium system for months after installing the plumbing. When I did maintenance on a pump with the teflon paste it would be a mess to clean and properly seal. While silicone 1 might appear to stick to PVC it can not form a chemical bond and will come off with a light/medium brush.

I was skeptical of using silicone 1 when I was first introduced to the method but its been 100% effective every time I have used it. In my current system I have silicone 1 on PVC threaded fittings for 3/4" returns, 1.5" returns, 2" drain line, and a 4" interconnect line between sumps. While silicone 1 might not be the best solution for every situation I will always put it out there as a simple solution for DIYers. If you have not tired it before it might be worth testing out on a fitting or two as an experiment and see if it works for you.

 

[rhostam]

Thanks all! Great feedback. I usually have everything I need in hand before starting a project. I have tons of spare parts from this project alone but didn’t end up making any mistakes. I am just surprised that this pump shipped with something that wouldn’t have a proper seal and no mention of needing additional stuff.

I used teflon tape, but I’ll check my application again. The leak is super small and only appears to happen when the pump is on max.

I’ll post an update when I get to it. I’ll pick up recommended sealants while at it.

 

[Flameback Pair]

@rhostam just wanted to leave you with this last tip. Once the fittings are together, do not try and smear silicone on them to try and stop a leak. This never works, looks very bad, and leaves a mess. It’s just a bandaid. A leaky joint must be taken apart and fixed properly or it will continue to leak which ever sealant you use.

 

[rhostam]

As promised, an update:

After the many comments, I looked at my application of teflon tape. It looked to be applied correctly. I've used the tape before in more customary applications (showerheads).

So, I decided to take a second look at the rubber gasket provided by Reef Octopus. It just looks like a gasket used for water hoses. On the VarioS outlet, there is a lip against which the union fitting should probably rest if tightened properly.

I removed the teflon tape and installed the gasket onto the VarioS outlet. It seemed an awkward fit at first. I then gently tightened the union fitting onto the VarioS. It looks like maybe that was its intended purpose since the barbed fitting they provided I think would have required it in this same position. The instructions don't say one way or another.

It appears I was mistaken in saying that Reef Octopus didn't supply the correct parts. My bad.

I have been running a circulation test for the past few hours on MAX and there is no evidence of a leak from that connection now.

I'm sorry for the churn, but I do appreciate the help.