The SImplest Overflow....

[spoofsjsc]

I been readin all these complicated overflow systems on the DIY section and I really dont understand why people go through sooo much effort. correct me if im wrong but If I were to buy 2 really big PVC pipes and put them vertical at the back of the tank going straight threw the bottom and into the sump, wouldnt that work perfectly fine?. i dont get this wholeuber complicated crap. I wanna keep it simple. Would this idea work?

And also does it matter if I use really big PVC pipes or small ones? because i want to make sure than those pipes can carry the necesary amount of water in case i decide in the future to have my tank cycle faster...

Oh its gonna work real well. pipe size... depends on the size of your tank and the power of your motor. IMO, use the bigger ones (2" and up) to be safe. They'll still work even if you upgrade to a more powerful pump in the future.

sometimes, though, people use the more complex drains because...
-they simply are not confident with drilling their glass tanks.
-they wanna drill but don't know how, don't have the tools, or cant find anyone they can trust to do it for them.
-they enjoy the whole D-I-Y idea and would like to see the fruit of their labor.

as long as it works, everything's ok.

 

[hurricane_redbone]

no what i said was the hole is at the bottom of the tank and u surround that with a box which goes up as high as u want the water level, that way the water height above the entrance of the hole is great but at most the water will drain that of which fills that container

edit/ put a pic up from http://www.glasscages.com/ that shows what i mean

I hate to break it to u but thats bull****. if u put that little box around it all thats gonna happen is that u will have a different water level inside the box... not gonna cause faster flow...

 

[spoofsjsc]

I hate to break it to u but thats bull****. if u put that little box around it all thats gonna happen is that u will have a different water level inside the box... not gonna cause faster flow...

your right, if he keeps the pipe.
i think, though, he plans to remove the pipe altogether and replace it with the glass box... leaving just the hole at the bottom of the tank surrounded by glass walls that would keep the water out. Rs200, is it?

 

[RS2000]

i would suggest that you go back and re-read that site cause apparently you don't understand jack of what they said. also the box would have no different in water height than that of the tank, to top of the box would set the height of the water level in the tank.

do into that calc and put in that fact that u have a tube coming up and that it sets the water level. say the hole is 1" and since its @ water level u have sweet F*** all water above that hole i'll put in 1/4" into the calc for this eg since the water depth in that calc is the water depth ABOVE the hole and u get a whooping 2.8224546012209872 gpm or around 170gph

same hole, same setup but with the box around it to sett the water height and the hole at the bottom. so say 17" tall of water (assuming for 18" tall tank) and look at that u get 23.274556888689407 gpm or around 1400gph


spoofsjsc yeh thats right just beat me to posting

 

[greenterra]

http://www.grow.arizona.edu/Grow--GrowResources.php?ResourceId=188

.

That is a great link that you posted RS2000.

The box setup is probably the most sensible set up I have seen so far.It regulates your tank water level,won't overflow your sump , won't lose prime should you have a power failureand going by the calculations on that link will flow way better.Also I think it would look better than having obtrusive pipes in your tank.For what it's worth,I think you explained it fairly well.
I will definately be going that route on my next tank.

 

[hurricane_redbone]

RS2000
I aint like dissin u but i just dont think it makes sense. I understand the laws of physics and all butwht your saying doesnt entirely make sense. Its true if you have a big tub of water and u stab a hole in the bottom the water will flow through much faster than if you stab a hole in the side somewhere near the top. But like i demonstrated in the picture below, once u make the glass box overflow an put the tube in there, there is a new water level established. The only way that the water is going to be higher than the hole is if the pipe cannot carry the water down as fast as its coming in, and then the pressue would build up and the pressure would make it flow faster. But the point of an over flow is for the water to leave as fast as it comes in. The fact that there is a large difference between the old water level and new water level does not create any extra pressure. If I were to drill a hole in the bottom of my tank with no box around it and no pvc tube going up it then the point where the water leaves would be under a lot of pressure and the flow would be really fast. But your calculations just dont add up man.

 

[greenterra]

RS2000
once u make the glass box overflow an put the tube in there.

I took it that he is doing away with the tube.

RS2000
The only way that the water is going to be higher than the hole is if the pipe cannot carry the water down as fast as its coming in, and then the pressue would build up and the pressure would make it flow faster..

I think that is his point.Most overflows I have looked at can only flow what size and gravity will allow.By returning the water back to the tank faster this water level should rise in the box.Knowing that bulk water pressure from increasd water hieght in the box will increase the flow out the bottom it should find its own level.If the water level stays very low in the box it would mean you can up the flow.
Correct me if I am wrong RS2000,this is how I see it.

 

[RS2000]

I think that is his point.Most overflows I have looked at can only flow what size and gravity will allow.By returning the water back to the tank faster this water level should rise in the box.Knowing that bulk water pressure from increasd water hieght in the box will increase the flow out the bottom it should find its own level.If the water level stays very low in the box it would mean you can up the flow.
Correct me if I am wrong RS2000,this is how I see it.

u hit the nail on the head.

Ure pump return brings back water faster than the bulkhead can flow @ level with the bulkhead, resulting in the water level rising above the bulkhead.

As this water rises and pressure builds and the bulkhead then flows more.

U simply work out roughly how high u want the water above the bulkhead and work out the bulkheads flow rate @ that pressure and then get a pump that can pump that amount of water or a little more, and either have a pump with a variable control on it or put a valve on the return line to restrict the flow slightly so u can fine tune the water level height.

This results in the water level being just under or the same as the glass box around the bulkhead and a greater flow rate

 

[spoofsjsc]

well said green tetra.
summarizing...
'the pipe proper' is out of the picture and what only remains is the bulkhead, which may be considerably longer than others we've seen. This stub of a pipe is then surrounded by a glass box. the water overflows from the top of the walls (at a rate almost the same as it is returned to the main tank) down to the bottom of the tank, overflowing out of the vertical bulkhead.
i got that right did'nt i?

on a side note, the top edges of the box can also do a good job of skimming the water surface, eliminating unwanted protein build-ups.

 

[hurricane_redbone]

yea but y not just use 3 inch pipes i garantee u a 3 inch pipe will flow just as fast as an overflowing 1inch....