Removing Overflow from Marineland 300DD

So I finally got my Marineland 300 Deep Dimension Aquarium. The thing is a beast.

I wanted to do a custom tank but the cost and delay (7 months and no accurate quote!) was too much. I decided to get a stock tank and make my own mods. More fun and way cheaper.

So the first thing is to ditch the overflows. They are siliconed in, but it appears they are added after the tank is put together. I’ve included some photos of when I did it. Of course, this probably voids your warranty — you have been warned. Also, if your tank leaks or blows up afterwards, don’t blame me.

I carefully slipped a razor blade behind the overflow and drew it down, but not all the way. Stop just above the base silicone that holds the bottom and side together. After freeing both sides you can push the overflow out.

Here is the left over silicone at the base. You can see that the bead was added after the main glass pieces were assembled.

Then just clean up the rest of the silicone from the glass.

I didn’t bother trying to get the little bit that overlaps off. It isn’t noticeable especially once sand is in the tank. No point making a weak point in the silicone.

A nice clean tank without overflows. I am still debating what to do about the holes in the bottom. I could put in the bulkheads that came with the tank and cap them. I’m never going to use them, so I may just silicone a largish piece of 3/4″ plate glass over that whole area.