Overflow height

[Ridwaan]

Hi guys...

I am in the process of building an overflow box in the back corners of my tank..

Water level is gonna be at 600mm high.

My question is, How high should my overflow box be?

I am trying to skim as much of the surface as possible.

Your advice will be appreciated..

Thanks
Ridwaan

 

[palmerc]

Surely also 600mm?

 

[Ridwaan]

Thanks Palmerc..
Been thinking of what you saying and it makes sense...The return pump will pump water into tank and tank water will rise over 600mm and overflow....

So the overflow height should be as high as where you would want your water level?...if my thinking is correct

 

[palmerc]

Yes, the overflow height will determine the water height.

One thign to remember if you overflow is too small or yoor return pump too powerful (high flow rate for tank/overflow size) you could have a water level slightly higher than the overflow (maybe up to a cm higher)

 

[Ridwaan]

So if I were to Make my overflow height around 580mm, I would just need to put a ballvalve on my Return line and set the water level this way....

 

[Alan]

Leave your overflow at the height you want your water, just make sure its big enough to handle the flow of your return pump. You dont want to drop your overflow below the water level by using ball valve otherwise you wont get any surface skimming.

 

[AndreT]

Ridwaan,

With an overflow, your main display's water level is controlled by the height of your overflow only. That being constant, the advantage is that only in your return chamber in your sump do you need to monitor your water level/top-up.

 

[Ridwaan]

Thanks for the info Alan and Galibore...

 

[Hill]

The height of the water level will be the overflow height plus x. Where x is the height of the water flowing over the overflow. For a given flow rate the wider the overflow the smaller the height of x will be. If you want your water level close to the top bracing this is something you need to work out.

Otherwise you end up like me with approx 15mm mater level over the overflow. Anything more and the water starts to touch the bracing on the far end of the tank. The tank is not 100% level.

 

[millepora]

Sheees I thought this was a trick question

 

[Smithers]

Sheees I thought this was a trick question

:smilielol5::wacky:

 

[Ridwaan]

Haaai,now yourll making jokes of my question.

 

[AndreT]

Ridwaan it can be a little confusing, but once you get your head around it you will see it's a very simple concept.

 

[millepora]

sorry buddy:innocent:

 

[Ridwaan]

Hehehehehe...
Its kewl mille.Its just that i saw a couple of tanks and their overflows is lower than the water level.This is where the confusion came along.

 

[palmerc]

What was the height difference in cm when u saw these tanks? Got any pictures?

Is the water level still higher than the overflow level when the return pump is switched off? If so that would be really amazing...

 

[Ridwaan]

No...the water level is not higher then the overflow when the pump is switched off....I was looking at the tanks on the showroom floor of exotic aquariums and the overflows look lower than the water level.

 

[palmerc]

Are you talking about the empty tanks or the smaller show tank?

 

[Ridwaan]

The SHowtank with all the clams inside just before you enter the goldfish aquarium...

 

[Ridwaan]

Ok...Maybe its because they have a stronger return pump...