Modular Marine Overflow leaking

[Peter Petronis]

I silicone mine and have zero issues.

If you dont mind me asking, where did you silicone and did you use gaskets?

 

[ca1ore]

Did you get rid of that small gap between the internal box and the back wall?

If this question was for me ....

That’s primarily why I siliconed the internal box, to eliminate the small gap and prevent detritus from getting in there. Since my version does not have the the removable skim box, I saw no downside. I did let it cure for a full week though.

 

[CoralNerd]

If you dont mind me asking, where did you silicone and did you use gaskets?

No gaskets just silicone the entire back box directly to the tank.

 

[CoralNerd]

Duplicate delete

 

[JCTReefer]

Old thread, but have a question for all you that have the removable version. How long does it typically take for the water in the tank to seep around the insert through the box and back down to the sump? Is it more like hours or days for this to happen? I haven’t installed mine yet, but am trying to get an idea. I had modular marine design mine to meet custom aquariums hole spacing requirements. That would mean a 6 3/4 drop in water level from the tank. That would roughly be about 47 gallons in a 72x24x28 tank.
Using 5/8 glass on the front and back, and 1/2 inch on the side panels, inside dimensions give me that number. So I’d be looking at 47 gallons plus back siphon from return pump. And also the running water level in the sump. There’s no way I can fit a sump big enough to handle all that potential overflow water. I guess I could do a simulated power outage and see just how long it takes.

 

[ca1ore]

I had suggested to MM a few years ago that they should route a groove in the skim box stubs to embed an O ring so that there is no leakage. My overflow does not have the removable box, but a friend of mine does. He wraps the ends of the skim box stubs with some Teflon tape which seals it pretty well.

 

[JCTReefer]

I had suggested to MM a few years ago that they should route a groove in the skim box stubs to embed an O ring so that there is no leakage. My overflow does not have the removable box, but a friend of mine does. He wraps the ends of the skim box stubs with some Teflon tale which seals it pretty well.

Great, thanks for the tip!!! I had considered applying a very thin layer of silicone to the fittings. I’ll have to experiment with it. In the garage that is!!! That’s a good suggestion on the groove and o ring.

 

[Water Dog]

I have the removable weir box on my MM overflow. It’s a very tight snug fit that does require a bit of effort to remove from the bulkhead when I want to give the weir box a cleaning. Whenever I do water changes, (I usually pull old water from the sump) I really don’t notice any water leaking down into the sump due to the press fit weirbox/bulkhead connection. It seems pretty watertight to me.

 

[JCTReefer]

I have the removable weir box on my MM overflow. It’s a very tight snug fit that does require a bit of effort to remove from the bulkhead when I want to give the weir box a cleaning. Whenever I do water changes, (I usually pull old water from the sump) I really don’t notice any water leaking down into the sump due to the press fit weirbox/bulkhead connection. It seems pretty watertight to me.

Thanks for sharing!!! Appreciate the input!

 

[EJReef]

I had suggested to MM a few years ago that they should route a groove in the skim box stubs to embed an O ring so that there is no leakage. My overflow does not have the removable box, but a friend of mine does. He wraps the ends of the skim box stubs with some Teflon tape which seals it pretty well.

The Fiji Cube overflow boxes have that notch and O ring on the skim box I believe.

 

[carlosec83]

Exactly, we are now including an extra set of gaskets for this purpose.

We are also looking into full sheet gaskets for between the tank and exterior box.

I would like to thank everyone who contributed and shared their experiences with our product in this thread. It is threads like this one that help us improve the design of our products.

I just received mine in July, there was no EXTRA gaskets... just the 2 attached to the bulkheads. No sheet gasket, followed all instructions and mine leaked. Thanks to everyone for their contributions and comments. I will order a second set.

 

[shred5]

I bet I have installed over a dozen of these and never a issue.
Not when they came with one or two. My last one came with two.
Do not over tighten, do not use silicone. Drill from the side the flange and gasket go incase of some break out of glass when you break through.

 

[TaylorPilot]

I bet I have installed over a dozen of these and never a issue.
Not when they came with one or two. My last one came with two.
Do not over tighten, do not use silicone. Drill from the side the flange and gasket go incase of some break out of glass when you break through.

That last part is important. Always drill the tank from the outside in...the side of the hole where you start drilling is always cleaner than the side the bit pushes through...