120 Build one or two overflows?

[McGee10]

If you want what's best for the tank, go as big as you can with no teeth.
The overflow needs to surface skim, and the bigger and flatter it is, the better it will do.

Why no teeth? my wrasses will go in the overflow.

 

[d2mini]

Because teeth cut down on the surface skimming ability, and they get full of algae and require cleaning.
You can have a cover made that fits over the top of the overflow with a inner lip that hangs down from the lid and allows the water to pass between the edge of the overflow and this lip but not the fish. Plus the cover prevents algae from growing inside the overflow since it blocks the light.

Your wrasses shouldn't get pulled over the edge. If anything, they will jump and end up in an uncovered overflow.

 

[McGee10]

Yes, the overflows out the back and centered are way better, accessible and way easier to clean.

Looks like I may have to look into it.
starting to look like i may be getting a 180 6'x2'x2'

 

[McGee10]

Because teeth cut down on the surface skimming ability, and they get full of algae and require cleaning.
You can have a cover made that fits over the top of the overflow with a inner lip that hangs down from the lid and allows the water to pass between the edge of the overflow and this lip but not the fish. Plus the cover prevents algae from growing inside the overflow since it blocks the light.

Your wrasses shouldn't get pulled over the edge. If anything, they will jump and end up in an uncovered overflow.

Dennis, will the coast to coast overflow be quiet?

 

[d2mini]

Length doesn't matter (for ummm... overflows. lol )
It's the waterfall effect you don't want so as long as your plumbing isn't too far down inside it so the water doesn't have far to fall once it flows over the edge it should be pretty quiet.

 

[sleepydoc]

Dennis, will the coast to coast overflow be quiet?

What matters for noise is the length, the flow (or more specifically, gallons per hour per inch) the height of the drop over the weir and whether you have teeth or not. For a given flow rate, a shorter overflow will be noisier, a longer drop will be noisier and a toothed overflow will be noisier than a smooth one.

 

[DarthReefer27]

bump. this thread caught my eye as i am in planning stage to build a 120 gallon mixed reef. i had planned on buying a 120 reef ready with dual corner overflows but after reading this thread, now i am thinking about a 120 regular tank and drill it myself, using the synergy reef overflow. my question though. isn't it harder to work with the plumbing with the overflow in the back of the tank if the tank is against the wall? i don't have space to have the tank more than a couple inches from the wall so I am not sure if that is the best idea. thoughts?

 

[sleepydoc]

bump. this thread caught my eye as i am in planning stage to build a 120 gallon mixed reef. i had planned on buying a 120 reef ready with dual corner overflows but after reading this thread, now i am thinking about a 120 regular tank and drill it myself, using the synergy reef overflow. my question though. isn't it harder to work with the plumbing with the overflow in the back of the tank if the tank is against the wall? i don't have space to have the tank more than a couple inches from the wall so I am not sure if that is the best idea. thoughts?

I wouldn't say harder, but you definitely need more room behind the tank.

Take some time and measure your space as well as the plumbing you plan on using. My 120 with 1.5" drains on the back needs just over 6" behind the tank. You can cut that down a bit by using 1.25" pipes, but I wouldn't go any smaller than that. Even if you don't have any pipes behind the tank you want a bit of space.

If you can't move the tank out that much, the options I can think of are:
- cut into the wall. This has been done before, but it takes some work to make it look nice.
- stick with the corner overflows. Functionally not as good, but easier.
- get a shallower tank. Not as good for aquascaping corals, but may work better
- get a dual corner flow, cut out the overflows and run the pipes up to a coast to coast overflow. A bit more work and has pipes in the back, but may be the best compromise.

 

[DarthReefer27]

I wouldn't say harder, but you definitely need more room behind the tank.

Take some time and measure your space as well as the plumbing you plan on using. My 120 with 1.5" drains on the back needs just over 6" behind the tank. You can cut that down a bit by using 1.25" pipes, but I wouldn't go any smaller than that. Even if you don't have any pipes behind the tank you want a bit of space.

If you can't move the tank out that much, the options I can think of are:
- cut into the wall. This has been done before, but it takes some work to make it look nice.
- stick with the corner overflows. Functionally not as good, but easier.
- get a shallower tank. Not as good for aquascaping corals, but may work better
- get a dual corner flow, cut out the overflows and run the pipes up to a coast to coast overflow. A bit more work and has pipes in the back, but may be the best compromise.

thanks for the info. i don't have a room to stick out 6 inches from wall unless I got a 90 which i don't want to do. i think I will stick with the 120 gallon dual corner overflow and see how it goes. this will only be my second tank (first is a 7 month old 29G biocube) so if it is not perfect then I will know down the road if i do something bigger:strooper:
as for cutting the wall, I don't think my wife would be very happy with me if I tried that. she doesn't understand why i need to go bigger already anyway (even though she loves watching the interactions in my tank).

 

[sleepydoc]

If you have to have the tank up against the wall and can't cut into it, you either have to have the pipes come out the end or through the bottom. For most people the end isn't a great option, so you're left with the botom. Since most 120's have a tempered bottom, I would get the dual overflow model. That way it will have 4 holes drilled for you.

What you do from there is up to you. Someone else posted a similar thread several weeks ago. I think it was in the DIY section, but do a search and see if you can find it as there was a good discussion of the various options.

In brief, the ones I can think of are:
- Dual Dursos, using either both holes as returns, or one as a return and he other as an emergency backup drain.
- Dual Herbies: Tricky to keep tuned from what people say, but higher flow and silent.
- Modified Bean using the 2 overflows (siphon and open channel in one corner, return and dry emergency in the other. You loose skimming from one overflow but you get the benefits of a bean. There are some other design considerations to this, so check with people before you set it up.
- remove the corner overflows and set up a coast to coast. Probably the best from a functional standpoint, but also the most work.

 

[DarthReefer27]

If you have to have the tank up against the wall and can't cut into it, you either have to have the pipes come out the end or through the bottom. For most people the end isn't a great option, so you're left with the botom. Since most 120's have a tempered bottom, I would get the dual overflow model. That way it will have 4 holes drilled for you.

What you do from there is up to you. Someone else posted a similar thread several weeks ago. I think it was in the DIY section, but do a search and see if you can find it as there was a good discussion of the various options.

In brief, the ones I can think of are:
- Dual Dursos, using either both holes as returns, or one as a return and he other as an emergency backup drain.
- Dual Herbies: Tricky to keep tuned from what people say, but higher flow and silent.
- Modified Bean using the 2 overflows (siphon and open channel in one corner, return and dry emergency in the other. You loose skimming from one overflow but you get the benefits of a bean. There are some other design considerations to this, so check with people before you set it up.
- remove the corner overflows and set up a coast to coast. Probably the best from a functional standpoint, but also the most work.

hmmmm, you mentioned putting the synergy reef on the end. in my setup, one side will be out of view and so perhaps i can get the non RR tank and drill the two holes in the side. if i go that route, perhaps I will not paint the back of the tank since our walls in the room are a very dark purple and only paint the side that gets drilled. i could even build out the cabinet to hide the plumbing on the side. choices, choices. i hate making choices.