Leak test reveals tiny leak in overflow box

[Eredus]

Performed a leak test yesterday. There seems to be a very small leak inside the overflow box. Woke up this morning to find a puddle about the size of a silver dollar inside the overflow box. Should I be concerned? The aquarium is a SC Aquarium 90 gallon 'Cube' 36x24x24

 

[Luis Figueroa]

Always be concerned if there's water leaking. I wouldn't be passive on this issue silicon it til you purchase another one or just buy a replacement if possible.

 

[vertigo01]

Just so I understand correctly. Are you saying that the tank is leaking into the overflow?
Am I correct in thinking that it is an internal and not external overflow?

If it were me and the tank were still under warr, I would contact the manufacturer for a replacement.
If it were used and outside of warr, I would reseal.

 

[Eredus]

@vertigo01 The tank is leaking into the overflow and the overflow is internal. I will contact the manufacturer as I have only had this aquarium for two weeks.

 

[sbash]

This really is a problem, and good on you @OP for identifying it. Granted, a very small puddle over night is a bit superficial.

However, picture this:

Your power goes out.
When the power is cut to your return pump, there will be a brief flow of water in the sump as it fills up with water from the overflow box, and water from the pipes.
The small leak in the overflow box turns into a big one, so over the course of the day, or night, the water level starts to normalize between the main tank and the overflow box. This means the overflow pipes are now going to be draining the water from the overflow box down into the already full sump. Based on your dimensions, if the hole is two inches below the top of the overflow, there will be an additional five gallons of water going into your sump.

Five gallons may be easy to handle in your sump, but you are looking at about 2.5 gallons of extra water into your sump for every inch the hole is below the overflow weir.

You are fortunate in only getting a tablespoon of water overnight, and it does seem superficial because the hole is inside the tank. However, as demonstrated above, that small issue can get out of hand...

 

[Chad Douglas]

I have a similar issue with a SC Aquariums aquarium. Internal overflow box leaks into the tank at the bottom. Clearly, the seal between the bottom of the overflow box and the glass is not sealed correctly. I've run another line of silicone along the bottom of the overflow box am waiting for it to dry/cure before I test the fix. But wanted to share this as another failure with SC Aquariums. I was unhappy with the ordering shipping process (it arrived two weeks after their promise date) and how have this issue. I did email them about the leak and their reply was nonsensical -- clearly English was not the responder's first language. I would not buy an SC Aquarium aquarium again.

 

[Waters]

What @sbash said..........I have seen it happen on a friends tank. The water will continue to drip into the overflow and into the sump. If that seal is leaking now, it will probably get worse over time. I would have it fixed correctly now before the tank is filled.