Modular Marine Overflow leaking

[ReefWithCare]

I just fixed my slow leak MM overflow by installing the provided gasket in the tank and getting a 2nd set from Amazon for between the the box and the tank....no more leak...honestly without the gasket between the tank and the box there is no way to stop the water from seeping between plastic and glass..

Hi there,

I just did the same thing and it worked like a charm. MM told me to place a second set of gaskets on the SAME side. I couldnt understand that advice so I didn’t listen to him put gaskets on both sides like Synergy’s and it worked of course [emoji849].

On to get this thing finally set up!

 

[Fin]

Hi there,

I just did the same thing and it worked like a charm. MM told me to place a second set of gaskets on the SAME side. I could understand that advice and both gaskets on both sides like Synergy’s and it worked of course [emoji849].

On to get this thing finally set up!

Glad it worked out for you. If you look around, every other manufacturer that makes these types of overflows (that I have ever seen anyway), includes 4 gaskets.

 

[Nano40]

Hi there,

I just did the same thing and it worked like a charm. MM told me to place a second set of gaskets on the SAME side. I could understand that advice and both gaskets on both sides like Synergy’s and it worked of course [emoji849].

On to get this thing finally set up!

Hopefully MM see this as an issue and includes the correct set of gaskets cause it's a pretty decent overflow box...it's been a while since I set up a new tank that I really should have known though that something didn't look right

 

[ca1ore]

I just fixed my slow leak MM overflow by installing the provided gasket in the tank and getting a 2nd set from Amazon for between the the box and the tank....no more leak...honestly without the gasket between the tank and the box there is no way to stop the water from seeping between plastic and glass..

Of course not, but any seeping will occur between the tank and the external box .... not dripping down the back of the tank. Even with a gasket under the flange inside the tank, water will still seep into the bulkhead threads because they are not sealed from the external box end. I think MM probably should include a second set of gaskets, if only because people seem to 'think' they're necessary.

 

[ca1ore]

Well I just looked at the design, and unless those slip fittings going into the bulkheads are water tight, the internal gaskets won't fix the problem because the water will slowly leak through the bulkheads. I would suggest making sure your sump can handle the excess water in the event of a prolonged power outage, because the tank will eventually leak down several inches if the power remains off for an extended amount of time.

Precisely.

 

[CoralNerd]

There telling you that because of your trim going around your tank. Your thick trim going around your tank is why the overflow box is leaking.

The exterior box needs to sit flush against the tank.

Was one set in the inside and the other set on the outside?

MM is telling me to to use 2 sets of gaskets on the same side [emoji848]

 

[Caravanshaka]

FYI, I added a 1/16” neoprene sheet gasket trimmed to match the overflow box between the tank and the box. I used the supplies gaskets between the bulkhead and the tank. I ha e no leaks at all, and the box is very secure against the tank.

I think it was $10 for the sheet gasket and 10 mins to trim it to fit.

Something should be included, but I much prefer the sheet to just another couple bulkhead gaskets.

 

[ca1ore]

I think using a 'sheet' gasket is a very good idea. I would have done this ..... if I had thought of it. That approach will also prevent the box from torquing.

 

[Nano40]

Of course not, but any seeping will occur between the tank and the external box .... not dripping down the back of the tank. Even with a gasket under the flange inside the tank, water will still seep into the bulkhead threads because they are not sealed from the external box end. I think MM probably should include a second set of gaskets, if only because people seem to 'think' they're necessary.

In this hobby we all have different experiences even with all the tools that we now have everyone's situation is unique...this was my resolution to this problem.

 

[ca1ore]

In this hobby we all have different experiences even with all the tools that we now have everyone's situation is unique...this was my resolution to this problem.

That's fine; if it worked for you then it worked for you. Spent some time in my career in product development and it is quite common to include 'features' in products that are actually unnecessary but make consumers 'feel' better.

 

[Modular Marine]

Of course not, but any seeping will occur between the tank and the external box .... not dripping down the back of the tank. Even with a gasket under the flange inside the tank, water will still seep into the bulkhead threads because they are not sealed from the external box end. I think MM probably should include a second set of gaskets, if only because people seem to 'think' they're necessary.

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.

 

[Caravanshaka]

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.

The sheet gasket is perfect, the box sits perfectly flat against the back of the tank and was a piece of cake to cut and install!

 

[Harrison Gordon]

I had the same problem. Except, on the back of my tank one of the holes had a little chip that ran bast the gasket so water was seeping from that too, even after I got four gaskets.

My SOLUTION:
I got the DIY gaskets and made two huge ones; so I had one gasket on the inside of the tank, the DIY between the tank and the box, and the second set of gaskets behind the nuts.

I had contacted the Modular Marine, and they said I could also try doubling up between the tank and the box, but with the drilling template in between. I thought that was a good idea, but so far my setup is working for now.

 

[Peter Petronis]

I am currently going through this too, a slow leak on one side. ( I am taking a break due to the holidays) I will try all of the above solutions as far as gasket placements. My "if all else fails" solution will be as follows:
A bead of silicone on the bulkhead inside the tank-this will prevent water from reaching the outside of the tank
A gasket placed between the box and tank on a paint removed, alcohol cleaned surface. This a back-up
Teflon tape on the threads of the bulkhead to prevent water from entering through the threads
Another bead of silicone on the nut of the bulkhead, to seal the water from the box leaking
I will also support the box too because I was told that this is a very heavy box by a knowledgeable LFS guy
One question, I am thinking of using plumber's putty instead of silicone, can anyone advise with certainty if this will this affect the water quality in anyway?
I welcome any input both negative and positive

 

[Harrison Gordon]

I am currently going through this too, a slow leak on one side. ( I am taking a break due to the holidays) I will try all of the above solutions as far as gasket placements. My "if all else fails" solution will be as follows:
A bead of silicone on the bulkhead inside the tank-this will prevent water from reaching the outside of the tank
A gasket placed between the box and tank on a paint removed, alcohol cleaned surface. This a back-up
Teflon tape on the threads of the bulkhead to prevent water from entering through the threads
Another bead of silicone on the nut of the bulkhead, to seal the water from the box leaking
I will also support the box too because I was told that this is a very heavy box by a knowledgeable LFS guy
One question, I am thinking of using plumber's putty instead of silicone, can anyone advise with certainty if this will this affect the water quality in anyway?
I welcome any input both negative and positive

Whoa! I think you might be taking this a little too far. It sounds like you either don't have gasket between tank and box, or there is paint on the tank. Trust me, as long as there are no chips, one gasket on the inside of tank and one on outside of tank will get the job done. And like I said, diy gasket if there is a chip. Don't recommend any putty inside tank, outside may not last and should not be your first solution.

Good luck!

 

[CoralNerd]

I silicone mine and have zero issues.

 

[ca1ore]

Silicone is fine. I used it to attach the internal skim box to the side of my tank. Just need to give it adequate curing time.

 

[CoralNerd]

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

 

[Saveafish]

I have 1 BIG one on mine. Here is where I found it leaking from. The exterior box where the threaded part comes through. It leaks back through the threads. You need another gasket. Each bulkhead needs 2
The smaller ones most likely not. But the bigger ones yes. Mine is the third one Ive seen in person than needs them due to the water level high enough to leak back through the threads.

 

[Peter Petronis]

Whoa! I think you might be taking this a little too far. It sounds like you either don't have gasket between tank and box, or there is paint on the tank. Trust me, as long as there are no chips, one gasket on the inside of tank and one on outside of tank will get the job done. And like I said, diy gasket if there is a chip. Don't recommend any putty inside tank, outside may not last and should not be your first solution.

Good luck!

This option is if all else fails