Height of overflow?

[zanzan]

Hello everyone,

May I know what is the safest height of the overflow and the top of tank? For those who don't get what I mean, I'm refering to the gap between the overflow and the top of the tank, where the water flows into the sump.

I'm planning to build a 24" x 24" x 18" tank with external overflow. So what's the safest height should I go with? 1" or greater?

[comycus]

lol a pic might help. My english not v. good, can't really visualize what you mean...

why do you need a gap btw overflow and top of tank for? what is the concern? Gravity will do the job.

[teebs]

You're talking about an external overflow box fitted to the back of your tank?

[jackywongto]

zan zan

I have not had time to reply to your PM.

My tank contact can be found in my thread... somewhere in mid.

apologies.

if I have time later, will PM you.

[zanzan]

comycus,I have no pics at the moment, will put one when I found.

Peter.Tee, yes!

jackywongto, okay noted.

I'm actually refering to the spot where the water enter the overflow box. The one with the teeth. I want to know, what is the recommended height for that?

[peacemaker]

I believe he means this. Other than the height, it depends on the flow rate of your return pump, the space in-between the "teeth", the width of the overflow, and even your piping. I'm not sure if there's a way to calculate that, but some tank makers are good at advising the type of overflow to suit your needs. Alternatively, you can cut a bit more, and use a sheet of glass or acrylic to adjust the level of overflow.

[Solo77]

think u give 4 inches different will be good enough.....anyway, u can adjust by changing yr return pump....

[zanzan]

Yes! Im refering to that. Thanks Peacemaker and Solo77.

May I know what are the recommended turn over rate for the return pump? Some says 5x, while other 10x. May I know your input on this.

[Solo77]

while turnover rates need to consider, you must also ensure your circulation through wave maker, etc. I will suggest not to be too ambitous as high return pump needs big valve and opening to support. For your tank, maybe you can consider 1260 or AB3000. Do note of elbow joint and headloss in your setup. All the best.

[peacemaker]

I'll use my tank as an example: the height of the "teeth" is approx. 2", the gap in-between each "tooth" is approx. 5mm, and width of my overflow is 4". My return pump is 1000 l/hr, and I have a K1 and K nano @ 1500 l/hr & 900 l/hr respectively. The height of the water level is almost half the height of my overflow.

Perhaps you might want to seek advice from the tank maker on the size of overflow needed for your tank dimensions. Usually, they will ask what pump you plan to use before giving you advice. Bro solo77 gave you pretty good suggestions, so you should check on them.

[zanzan]

I'll use my tank as an example: the height of the "teeth" is approx. 2", the gap in-between each "tooth" is approx. 5mm, and width of my overflow is 4". My return pump is 1000 l/hr, and I have a K1 and K nano @ 1500 l/hr & 900 l/hr respectively. The height of the water level is almost half the height of my overflow.

Perhaps you might want to seek advice from the tank maker on the size of overflow needed for your tank dimensions. Usually, they will ask what pump you plan to use before giving you advice. Bro solo77 gave you pretty good suggestions, so you should check on them.

Thanks Solo77 and peacemaker.

Peacemaker,

So what you mean is that there is still 1" left for the water to rise before it overflows, right?

[peacemaker]

Thanks Solo77 and peacemaker.

Peacemaker,

So what you mean is that there is still 1" left for the water to rise before it overflows, right?

Yup!

[zanzan]

Thanks!