Internal or External overflow... Help choose.

[newbreefer316]

I'm looking into picking up a 6ft planet aquarium tank and am trying to decide between internal and external overflows. I really like their ghost style overflow and how open it keeps the tank but I think I could get away with a wider tank if I go with their internal overflow.

I'd probably have to go with a 24" with the external overflow but could get away with a 27", possibly even 30", since the tank can be closer to the wall with the internal.

I'm thinking that the wider tank makes up for the space taken up by the overflow but am open to hear the pros and cons of either way.

 

[cracker]

In my opinion at least , external overflows,that are between the wall & tank "can " hard to work on . You will need some rooms for the overflow & a little more.

 

[User1]

Internal is just that, internal to the tank so it will take away some space. Not sure if that matters or not but that is what it does. External overflow takes that wasted space and moves it behind or on the side of the tank. That is really the only difference honestly. Pros and cons of both but I personally prefer it outside and that is what I ended up with.

 

[ca1ore]

If an exterior scupper box really would preclude a deeper tank then go internal. If you would really just get the same tank anyhow, then external is the way to go IMO.

 

[newbreefer316]

If an exterior scupper box really would preclude a deeper tank then go internal. If you would really just get the same tank anyhow, then external is the way to go IMO.

That's basically where I'm at. I'd prefer external but if I can squeeze a bigger tank in with an internal box then I'll probably go that route since it's probably going to end up being a positive gain in volume.

I figure I would keep an external overflow tank 8-12" or more off the wall so I should easily be able to add at least 3" more but could probably get 6" out of it. End up with a 72x30x24 instead of 72x24x24

 

[AquaDaddy]

I am currently wrestling with this question. I really like the external, and currently have one by eshopps which works great, but would really like to be able to place my tank against the wall if possible. Seem like a lot of space to give up, not to mention the aesthetics since people will walk by the side of my tank often. Have there been some really nice designs in covering the space? I suppose I could build the stand larger and only the tank has space behind it. Since I don't even have my new tank yet and am still designing, what are the really nice options for internal?

 

[Davy Jones]

Keep in mind having a 30" width is harder to light, and may require additional lights!

 

[AquaDaddy]

Thanks for that. Very valid point, which may drive me to a 150 with internal. (trying to stay around 6'). And I was thinking 60x30(ish)x24, but would have to figure out how to light it first!

 

[foxt]

My 6ft long 220g custom tank from coast-to-coast has an exernal box. Tank is 72x30x26. I fought for every inch in each dimension. I also did not want an internal box. In my opinion, when they get loaded up with coralline they take away from the tank. The back of my tank is a flat pane of glass with holes drilled in it and a weir applied directly over those holes. Very sleek and works well.

If i recall correctly, the external box added 6" to the depth of the tank. I have the tank about 7" off the wall, front pane of glass is 37" off the wall. My drain lines are 2", so with the bulkheads and elbows, the tank would still need to be maybe 4" off the wall? So I could have gone 3" deeper with an internal box and have the front glass in the same spot, 37" from the wall.

That extra depth of 3" would not have been worth the tradeoff to me, requiring an internal box. But easy for me to say, i already have 30," front to back.

But 6" is a different story. Given a choice between 30" + internal, or 24" + external, i would learn to live with the internal and take the 30". But if there is any way for you to make 30" work eith an external, that would be my first choice.

 

[Devaji]

oh man that quite the question eh?
I am moving my SCA 90gal 36x24x24 it has a monster of an internal over flow witch makes aqua scaping a pain. I was thinking about drilling or going HOB but like you said it a pain to move the tank 6-12" off the wall. and that is why reef ready or internal overflow became so popular. but as you know they tank up so much real estate...on a long 6' tank it might not be a big deal but on a small tank it sure is...

can you do a peninsula? that would be my 1st vote.
if not and you need the tank up flush with the wall then well interal overflow. I think the 30" with would make up for it. how many overflows will you have? placement?
in my cubeish it's right in the middle but for you 6' tank many in the Connors?

 

[ca1ore]

Keep in mind having a 30" width is harder to light, and may require additional lights!

Yeah, maybe ..... but then maybe not. When I moved from a 24" to 36" deep tank I decided to just use the same set of lights and not put anything in the front 6" or so - just sand. Worked really well and significantly reduces the amount of algae that grow on the front. Led me to the conclusion that most people don't light their tanks correctly.

 

[ca1ore]

external overflows that are between the wall & tank "can be" hard to work on

Oh yes, no question about that - though how often, really, do you need to be in there? I bought one of the Modular Marine units and had to give 5" of space between the back of the tank and the wall. Getting in there is a pain, but not having an obtrusive internal overflow is well worth a bit of cursing.

 

[Davy Jones]

Yeah, maybe ..... but then maybe not. When I moved from a 24" to 36" deep tank I decided to just use the same set of lights and not put anything in the front 6" or so - just sand. Worked really well and significantly reduces the amount of algae that grow on the front. Led me to the conclusion that most people don't light their tanks correctly.

Its hard to argue with a tank like that! It also depends on OP's willingness and ability to correctly place corals, this works very well for you since you leave the front without anything that needs intense lighting! I really like the clean look your tank has without anything on the sand bed however, and hope to be able to do the same when i finally upgrade tanks

 

[ca1ore]

To be honest I did it mainly because this is the first acrylic tank I have ever owned and I was paranoid about scratching the front. So I figured if I did the lights so that almost none falls on the front pane I'd be cleaning it a whole lot less .... and chance of scratching it would be less. It wasn't until after that I actually concluded it may be a fundamentally better way to do lighting. Right up there with Alexander Fleming

 

[hart24601]

I love me external overflows, but like others said if you can get deeper tank vs external I would go deeper. My tanks are generally not right against the wall so I go external, but I would pick deeper for sure if I had to choose.

 

[AquaDaddy]

Not quite 6', really thinking 5'. But you're point is valid, maybe I do a compromise, and go with approx 27", and do the new synergy reef which is only a couple inches of the wall.

 

[Carl C]

I am currently wrestling with this question. I really like the external, and currently have one by eshopps which works great, but would really like to be able to place my tank against the wall if possible. Seem like a lot of space to give up, not to mention the aesthetics since people will walk by the side of my tank often. Have there been some really nice designs in covering the space? I suppose I could build the stand larger and only the tank has space behind it. Since I don't even have my new tank yet and am still designing, what are the really nice options for internal?

hi Ed, what did you decide (internal , or external ? ) thanks ! Carl

 

[Ari_Ball]

internal is too easy to blocking the light, but fish loves to hide under it

 

[AquaDaddy]

hi Ed, what did you decide (internal , or external ? ) thanks ! Carl

I'm about 90% sure I'm going with some type of external. I am leaning toward a shadow type, but from Crystal Reef Aquatics, or just having a glass overflow with a weir the entire length. I'm thinking of having Crystal Reef make my tank too and they have a great overflow where they notch out the back for put on an entire glass box and the wier inside the tank. Seems like that would be the best of both worlds plus super quiet. So, leaning there. Will be pulling trigger soon, but can safely state I've ruled out internal. Too limiting, invasive and potentially distracting, for me, of course.

 

[ddrueckh]

I had the exact same decision to make as you. I decided that I would rather have the deeper tank with an internal overflow than a narrower tank with an external overflow. In the end, I end up with much more space than I would of had with an external overflow.