Alternative to Slotting aquarium back for horizontal overflow

[OriTeper]

Hello all,

first id like to say great forum, very informative and interesting stuff

I've been reading about horizontal overflows and was thinking of maybe doing an external one. i saw a post discussion on slotting the back wall of your tank to be lower and create an external overflow, of course this is a technically challenging project. but i thought of 2 alternatives and wanted to see what you guys thought:

1. (this can only be done if your custom building your tank) have the back wall cut an inch shorter then the side and front glass, thus eliminating any corners and uneven stress, ( i think, i am not an engineer)

2. instead of making the back wall lower, make the sides and front a bit higher with some thin horizontal stripes of glass or acrylic, rendering the back wall relatively lower and producing the same effect. (can be used on existing tanks without risk of altering them - worse case the rim breaks)

what do you think? personally i prefer option 1 since i will have my new tank custom built, can anyone think of why its not good to do it this way?

oh and also id like to now if these kind of overflows can be tweaked to be virtually silent (i read posts about how to minimize noise but i cant find info on how silent you can actually get these to work).

another idea was what if instead of plumbing the back of the tank to pipes i would turn the external into a hybrid funnel-overflow box that would extend the bottom of the external box in a funnel like fashion all the way down to the sump.
why? ive seen pics of many externals and all of them require the tank to be spaced fairly well from the wall (due to piping and elbows). but this way you can custom build it super thin and only use pipes down in the sump area (i dont think even that it will be load since this system will be thin water level should stay high without air getting sucked in (just going on instinct here).

ok i think thats enough for question for my 1st post

Thanks in advance for any comments and/or feedback you guys care to share

 

[roblou]

Well, I think without the slotting, you will have fish, snails, etc that will make their way from your tank to your overflow. From there, maybe down to your sump.

If you're having your tank custom built, is there a reason you don't want to just have an external overflow built and the back wall slotted?

 

[OriTeper]

Well, I think without the slotting, you will have fish, snails, etc that will make their way from your tank to your overflow. From there, maybe down to your sump.

If you're having your tank custom built, is there a reason you don't want to just have an external overflow built and the back wall slotted?

i dont see how slotting will prevent fish/snails going over either (im talking about an open slot that makes part of the back wall shorter not a horizontal long hole in it) there will have to be some kind of guard/mesh/sponge in any case.

i think having the back wall cut a bit shorter along the whole top of it is better for two reasons:
1. will result in a stronger tank with less stress points (no angled or cornered cuts)
2.the overflow will truely be 'coast to coast' producing better skimming and perhaps a seamless overflow (more visually aesthetic)

 

[krisfal]

I think the tank in this thread is kind of like what you are talking about with the back wall shorter http://www.reeffrontiers.com/forums/showthread.php?t=7669 maybe you can get some ideas from it!

 

[OriTeper]

I think the tank in this thread is kind of like what you are talking about with the back wall shorter http://www.reeffrontiers.com/forums/showthread.php?t=7669 maybe you can get some ideas from it!

that tank is actually slotted not the whole back wall is shorter just a portion in the middle.

 

[OriTeper]

double post

 

[dhnguyen]

It should work just fine I think. Actually the surface skimming of the entire back panel will be excellent IMO. And you're absolutely right, the slots don't really do squat to stop snails and fish from going over as they are more of a false sense of security if you ask me.

Only problem I could see is if your tank requires a center brace, how would you work this in?


Keep us updated.

 

[dnjan]

If your slots (teeth, actually, if you are thinking about the parts sticking up) extend to close to (or touching) a euro-brace, it is very effective at keeping all but the smallest fish and snails from going over through. They can't go over the top.

 

[OriTeper]

Only problem I could see is if your tank requires a center brace, how would you work this in?


Keep us updated.

just to clarify cause im not sure, this brace would be a piece of glass sitting on top of the tank across the width of the tank in the middle?
if thats what you meant then i dont think i can have it built with that. is a center brace mandatory for big tanks (it will be 2meters long and about 0.5meters wide or can you just use thicker glass?

actually i just thought of something, if i really must have a brace there, maybe i can glue a vertical stripe of glass to the back side of the back wall. this strip will be the same height as the front and side panels of the tank and i can connect a brace to that from the front.
so this brace will split my overflow but i can still use the original plan.

another thought, does this brace have to be level? what if i just brace the tank like it is? the brace will sit in a slope but will that make it less effective?

 

[dnjan]

If you try to make a 2-metre-long tank with thick-enough glass so as to not need bracing, you will probably not be happy with the tint (lack of clarity) of the glass.

Also, if this is a custom tank (for a reef), why only 0.5 metre front-to-back? I think you will be much happier with that size of tank if you increased the front-to-back distance.

 

[OriTeper]

If you try to make a 2-metre-long tank with thick-enough glass so as to not need bracing, you will probably not be happy with the tint (lack of clarity) of the glass.

hmm good point, so what do you think about using an angled brace like i mentioned above?

Also, if this is a custom tank (for a reef), why only 0.5 metre front-to-back? I think you will be much happier with that size of tank if you increased the front-to-back distance.

actually its going to be a planted freshwater with discus (gasp!). i know this is a reef forum but i saw you guys have more info on this kind of overflows then freshwater forums would (most use canister filter with a siphon and no sump). but i have plenty of space for one with drainage right next to where my tank will be, and i wont put an over the top siphon on this thing (don't want 150 gallons of water on my floor, thanks). so i am looking for the best way to overflow my tank (best for me = silent and unobtrusive) and horizontals seem to fit the bill.

 

[Dirtsquirt]

If it's being custom built...

GO ACRYLIC!

Or if you don't want to do something like that I believe it's possible to do the 3 viewable sides in a thinner glass with a brace tieing them all together and have the back shorter wall made of the thick stuff.

Would that work?

-Dan

 

[dnjan]

I was going to say that I didn't think that the angled brace would be a good idea with saltwater, because of salt creep. But since this isn't a saltwater tank, no problem.

Still, I would probably just not have the tank overflow along the entire back. Have a center section around 300mm that it normal height, attached to the brace, and then have the reduced-height overflow (though I would still prefer a toothed overflow to keep parts of plants from flowing over the top) on either side of that, all the way to the end.

 

[dnjan]

If it's being custom built...

GO ACRYLIC!

Or if you don't want to do something like that I believe it's possible to do the 3 viewable sides in a thinner glass with a brace tieing them all together and have the back shorter wall made of the thick stuff.

Would that work?

-Dan

Two half-metre-long sides would not be able to brace a two-metre-long front. (Euro-brace-style) Unless, of course, the euro-brace covered most of the top.

 

[JoshF]

So, from my understanding so far of the horizontal overflows the main benefits are better surface skimming and reduced noise with higher flow.

I'm also a planted tank person (small 20 gallon tall) and it seems like the flow rate through a sump would me MUCH lower than with salt-water reef tanks. If you had even a single built-in overflow it's going to do reasonable surface skimming, and with the slower flow down the drain noise shouldn't be much of a problem. Check out modifications for the stand-pipe in the overflow called a "Durso mod." Very good for reducing noise.

Since the flow isn't much of an issue for you, the internal overflow will give you a MUCH cleaner look and is a pretty standard design.

A single overflow going down to a wet-dry filter beneath the tank should look really nice.

If you use CO2 supplementation, you might want to tie it to a pH controller because increased surface skimming will tend to off-gas all that CO2 you just added. Fortunately, CO2 is cheap though the set-ups aren't. On a 2 meter wide tank you'd probably want at least 2, if not 3 CO2 bubblers along the back to get even CO2 distribution. There are relatively cheap sintered glass bubblers that work pretty well. I don't have a link, sorry!

Sounds like a fun project! What are you planning on using for lighting?

 

[OriTeper]

If it's being custom built...

GO ACRYLIC!
-Dan

why? doesnt glass look better and less scratch resistant? TBH i havnt gave it much thought, just assumed glass is better for me. convince me!

Or if you don't want to do something like that I believe it's possible to do the 3 viewable sides in a thinner glass with a brace tieing them all together and have the back shorter wall made of the thick stuff.

Would that work?

-Dan

that sounds good, but will it be strong enough?

anyone know of a reliable aquarium manufacturer on the web that would perhaps be willing to answer these question?

 

[OriTeper]

Still, I would probably just not have the tank overflow along the entire back. Have a center section around 300mm that it normal height, attached to the brace, and then have the reduced-height overflow .

kind of like what i mentioned above, only instead of leaving the center piece in the back higher for the brace, i thought you could attach a wide stripe of glass standing vertically to the back of the tank to hold the brace.

something like this:

I had another idea (kind of radical i think):
what if i have the overflow on the side, and turn it into something of a waterfall? here is a sketch (i took a pic of a 'Wall-waterfall' from the web for illustration and pasted it):

pros and cons i can think of:
+ no need to plumb the overflow (except connecting the lower box with the sump.
+ the box of rocks can double as a mechanical filter and i can build it to be easily removed for cleaning.
+ soothing sound of waterfall (as apposed to the gurgling and slurping of overflows)
+ cool waterfall in the living room
+ releases negative ions to the air (cleans the air)

- faster Co2 loss (which im guessing can be compensated for with higher Co2 injection)
- my cats might want to drink the water, might not be so bad for the cats but im worried about hardness swings when my top-off system replaces what they drink. on the other hand they dont drink that much, maybe 1/4 gallon a day (the tank will be about 175gl) so that might not be a problem
- soothing sound of waterfalls - even when you dont want it...

what do you think?

 

[moortim]

I think you have some very cool ideas here and I like both the back overflow and the side/waterfall thing. I would say either can be done if you want to break away from the norm, I would think that you should check into who will build the tank and find someone who is willing to try something new and can engineer the idea along the way (you don't want to get the glass thickness wrong).
The acrylic idea is because acrylic is clearer than glass. The next time you look at a glass tank try looking through the front pane of glass the long way (from the side), it's very dark, acrylic isn't. Some people don't care but I like it, acrylic also insulates better, which means less electricity to heat it in the winter, more to keep it cool in the summer. Disadvantage is acrylic scratches and you will need a pretty crazy top brace to make it work. I guess you just need to think the crap out of this idea to make sure you have everything figured out before hand.
Good Luck,
Tim

 

[OriTeper]

I guess you just need to think the crap out of this idea to make sure you have everything figured out before hand.
Good Luck,
Tim

absolutely right! i wont start building it for another few weeks so i want to take this time to figure out the best design for me.

btw, does anyone know of any manufacturers on the web that might be willing to help me design this thing (such as what type of glass to use, will my design hold the pressure of water etc..)

thanks

 

[dnjan]

You should add a location to your displayed profile, since that way people could recommend a local tank builder.