300 DD with mod to remove 1 corner overflow

[Sgoldstein]

Hi Everyone,

I have an opportunity to pick up a Marineland 300 DD tank for a great price...and i will be transplanting my 90 gal mixed reef into it....however i would like to set the tank up to have the 3' side against the wall and have the 6' come out into the room...like a wall divider...this way we can see both 6' sides of the tank and one 3' side.

My question is about flow rate if i removed one of the corner overflows.... this way the tank will be much more aesthetically pleasing but i am concerned that 1 drain and 1 return is insufficient.... any ideas? other than drilling a new corner overflow on the same side at the corner overflow i plan on leaving?

Thank you everyone

 

[Drae]

Use both holes in the 1 overflow for a herbie full siphon. A 1" full siphon would flow the 1500 gph (tops) that you would need (5x tank volume+) and the 1.5" drain for backup would be plenty. Then buy a sea swirl ( or not) and run the return over the back of the tank.

 

[Sgoldstein]

Thanks for the feedback...
I am not familiar with the term Herbie full siphon or sea swirl... Gonna look that up now.

Thanks drae

 

[ridetheducati]

use both holes in the 1 overflow for a herbie full siphon. A 1" full siphon would flow the 1500 gph (tops) that you would need (5x tank volume+) and the 1.5" drain for backup would be plenty. Then buy a sea swirl ( or not) and run the return over the back of the tank.

+1

 

[triggreef]

On the side that you get rid of the overflow, I would suggest that you should still install a bulkhead, and cap it off. I have seen some people just silicone a small piece of glass over those holes. That is scary as hell.

Also I am fairly certain the bottom is tempered glass. They drill those holes prior to tempering the glass. So in other words, don't drill that tank.

Personally I don't think that you'll have any issue with only using the one corner as long as you use both of those holes as drains like someone else said. I would have the majority of the return water come in at the opposite end of the tank though. But that's just me.

 

[ridetheducati]

Poor water circulation is an inherent problem with peninsula systems. Consider this during planning.

 

[ca1ore]

On the side that you get rid of the overflow, I would suggest that you should still install a bulkhead, and cap it off. I have seen some people just silicone a small piece of glass over those holes. That is scary as hell.

+1

Also I am fairly certain the bottom is tempered glass. They drill those holes prior to tempering the glass. So in other words, don't drill that tank.

I actually don't think any of the big ML tanks use tempered glass, but certainly the sides do not, so drilling a few return holes in the top is doable

personally I don't think that you'll have any issue with only using the one corner as long as you use both of those holes as drains like someone else said. I would have the majority of the return water come in at the opposite end of the tank though. But that's just me.

Herbie will be more than sufficient. As long as you use pumps for in-tank flow, 3-5x display volume through the sump per hour is more than enough.