Leak at return pump union

[mpatterson42]

I bought a used 40G tank drilled with overflow and return and all plumbed. I connected everything and am doing a leak test with RODI and it seems good except for a drip on the return pump union.

Video:

I turned the pump off and completely disconnected the union, dried everything, then reconnected it. However when I started the pump back up the drip started again after about a minute. It's definitely coming from where the PVC pipe and union are because it dripped for a little bit longer after I disconnected the union.

I've hand tightened it pretty tight but didn't want to do more in case I damaged something. I also tried to loosen it a bit if it was too tight but again no real difference. About 2 drips a second.

Any suggestions?

 

[KrisReef]

Silicone GREASE (not sealant!)

If it doesn’t stop leaking then a new seal or a new union will be needed.
Try grease first. If it leaks try a tiny bit of tightening, and hopefully it will stop leaking

 

[mpatterson42]

Thanks, I'll give it a shot. Where exactly should I be applying it? All of the parts that touch each other?

 

[exnisstech]

Grease the oring is probably what Kris means. Also inspect both surfaces for imperfections. I had a similar leak when I set up my last tank. I found a burr on one side of the flange that prevented it from fully compressing the oring. If all is good then like Kris mentioned it's time for new oring or union.

 

[208reef]

I would buy a new o-ring. You can find them on most reef supply sites that sell plumbing supplies or even at Lowes/Home Depot. The grease will help prevent them from getting brittle, but the o-ring still needs replaced every couple years. Chances are the one you have now has never been changed or maintained properly with grease. The leak may continue to get worse as the gasket wears more, so I would start fresh with a new one and grease it so it stays good.

 

[mpatterson42]

Looks like there's no o-ring at all, unless I'm missing something? What's the best way to get one that fits, just take it to Home Depot and show them?

 

[KrisReef]

The oring goes inside the center circular oring slot.

 

[KrisReef]

If you can find the same brand/size of fitting you might be able to buy the fitting to get the proper o-ring. They are not always easy to find replacements for. I have bought new fittings and replaced the entire fitting (with a new oring) just because I couldn't find the proper replacement seal. If you do buy a new fitting, always open them up to ensure the seal is inside before you buy it. That's another problem that I have run across more than once.

 

[exnisstech]

Maybe home depot or a good mom N pop hardware store. An auto parts store like Napa maybe be able to help also, they have a pretty good selection. I'm really surprised it didn't leak worse than it was.

 

[FUNGI]

Maybe home depot or a good mom N pop hardware store. An auto parts store like Napa maybe be able to help also, they have a pretty good selection. I'm really surprised it didn't leak worse than it was.

Dont forget Harbor Freight....and Ace Hardware for sure has these....

 

[PharmrJohn]

I would buy a new o-ring. You can find them on most reef supply sites that sell plumbing supplies or even at Lowes/Home Depot. The grease will help prevent them from getting brittle, but the o-ring still needs replaced every couple years. Chances are the one you have now has never been changed or maintained properly with grease. The leak may continue to get worse as the gasket wears more, so I would start fresh with a new one and grease it so it stays good.

This.

 

[208reef]

Looks like there's no o-ring at all, unless I'm missing something? What's the best way to get one that fits, just take it to Home Depot and show them?

Do you know what diameter the pipe/hose is? From your video it looks like maybe 3/4" or 1"? If you let me know the size I can link you to some options.

It also may say somewhere on the union if it is 3/4", 1", or other.

 

[mpatterson42]

Home Depot was a bust, although the guy helping me definitely did everything he could (opened multiple packages of O-Rings and also checked if any of their unions had o-rings that would fit). Ace Hardware had what I needed, they didn't really have o-rings but they had the exact same model of 3/4" union that I had (I'm glad I took it with me). Bought a new union and just took the o-ring out of it, applied some silicone grease and fitted everything back up.

It's been running for 10 minutes now and I'm no longer seeing a drip.

I appreciate the help everyone!

 

[mpatterson42]

When I first set everything up and started running water I was surprised at how quiet the whole thing was. There was some water flowing noises in the baffles but for a quick fix I just put some polyfil in there. Really the only sound I heard was the dripping from the return pump union joint.

After fitting everything up the dripping is now gone, but suddenly the return pump is making a very audible buzzing sound. It's a SICCE Syncra Silent pump. I let it sit overnight hoping that might fix it. I played around with the positioning, I put a rubber mat underneath it, I even tried removing the o-ring to see if that made any difference (it didn't so I put it back). The rubber mat made the most difference but it's still louder than it was before I started working on the drip.

The pump has flexible tubing to connect to the union joint, I did not change the flexible tubing or the union, I just added the o-ring from the union I bought.

I'm not sure what else to try or what could've happened. I never plugged in the pump when it was out of the water, I did take it with me to look for an o-ring but handled it gently the whole time.

Is there anything else I can try to reduce the buzzing?

 

[FUNGI]

When I first set everything up and started running water I was surprised at how quiet the whole thing was. There was some water flowing noises in the baffles but for a quick fix I just put some polyfil in there. Really the only sound I heard was the dripping from the return pump union joint.

After fitting everything up the dripping is now gone, but suddenly the return pump is making a very audible buzzing sound. It's a SICCE Syncra Silent pump. I let it sit overnight hoping that might fix it. I played around with the positioning, I put a rubber mat underneath it, I even tried removing the o-ring to see if that made any difference (it didn't so I put it back). The rubber mat made the most difference but it's still louder than it was before I started working on the drip.

The pump has flexible tubing to connect to the union joint, I did not change the flexible tubing or the union, I just added the o-ring from the union I bought.

I'm not sure what else to try or what could've happened. I never plugged in the pump when it was out of the water, I did take it with me to look for an o-ring but handled it gently the whole time.

Is there anything else I can try to reduce the buzzing?

Did you take it apart and cleaned everything?

 

[mpatterson42]

I did not, I guess that's the next thing I'll try. It's probably not a bad idea to pick up some kind of pump cleaner either (looks like Sicce makes a brand, I'll check with my LFS to see if they carry it).

 

[FUNGI]

Pump cleaner? I just use a toothbrush and bottle brush.....but, you do you.....also, can you run the pump without connection to the flex tubing, and see if it still makes the noise as that might the next cause...since everything is "tight" now....

 

[FUNGI]

process of elimination.......

 

[mpatterson42]

Oh I'm new at this and usually do what YouTube recommends :rolling-on-the-floor-laughing:

I'll give a basic cleaning a shot and run it while it's not connected. Thanks!

 

[FUNGI]

The Dollar Store is your friend........