Why is the drian pipe in the overflow adjustable?

[rdefino]

I have a 210 with 2 overflows using the all-glass durso type pipe drains. The pipe drains are adjustable; I can slide them up and down. Why? What benefit does this give me?

Thanks

[reefnetworth]

increase or decrease flow.
the lower they are the more syphon is produced. i adjust mine to keep the water in the sump regulated to my desired depth...

[rdefino]

So if I lower them, it will drain more water? I thought the amount of water draining depended on how much was being returned to the display tank.

[t-rock]

Yea, I always thought it depended on the output of your return pump. You would think that if you were to decrease the amount of water returning to the sump by any means except for the return pump that your tank water level would rise above the overflow and spill out to the floor???

[schneijt]

The amount of water that drains to the sump depends on how much water is being returned to the tank via the return pump. I'm sure there is a hole drilled into the top of your drain pipe, so I don't think it's used to adjust the syphon, since air entering through the hole would prevent a real syphon from forming.

Personally, I use my drain pipe to regulate the level of the water in my tank. With the pipe all the way down, the water level is as low as the Megaflow will allow it to be; the water line in the tank is the same as the lowest level at which water can flow over the black plastic Megaflow and into the partition where the drain pipe is. I usually like the water a half-inch higher than this, though, so I bump up the height of my drain a little bit until the water level stabilizes 1/2" higher up into the "teeth" of the Megaflow.

I'm sure that the drain pipe doesn't determine water height alone, since the amount of flow coming back to the tank via the return pump probably plays a part with your water level in the tank and such. But, in general, the height adjustment of the drain pipe is to allow you to make small changes in the water level of your tank. Also, for taller tanks, it's adjustable so that one size drain can fit a variety of tank sizes. I guess you could say the height adjustment is two-fold, to adjust water level in the tank a little bit and to allow you to use a taller tank someday without having to buy a new drain pipe.

-Joe

[noboddi]

also, if you have two overflows, you can adjust the rates of each. If one overflow goes to a refugium and the other straight to the sump, you might very well want the refugium to draw water slower.

also, with two you will have to adjust if you want them to draw water at the same rate.

[Jadinop]

The All Glass drains pipe are adjustable because the same kit fits different height tanks. They have no affect on amount of flow as that is regulated strictly by the return pump. The amount of water that the return pump pushes over the top of the overflow is what goes down the drain, the height of the pipe inside the overflow cannot affect this. The drain pipe itself is also not used regulate the water level outside the overflow. The pipe is adjustable so you don't have the splashing noise from the water level inside the overflow being too low. You want to set the height so the water level inside the overflow is only an inch or two below the top of the overflow wall.

[NanoReefWanabe]

Originally posted by Jadinop
The All Glass drains pipe are adjustable because the same kit fits different height tanks. They have no affect on amount of flow as that is regulated strictly by the return pump. The amount of water that the return pump pushes over the top of the overflow is what goes down the drain, the height of the pipe inside the overflow cannot affect this. The drain pipe itself is also not used regulate the water level outside the overflow. The pipe is adjustable so you don't have the splashing noise from the water level inside the overflow being too low. You want to set the height so the water level inside the overflow is only an inch or two below the top of the overflow wall.

Exactly what they said....

[schneijt]

Originally posted by Jadinop
The drain pipe itself is also not used regulate the water level outside the overflow.

Actually, you can regulate the water level outside the overflow by raising the pipe. If you raise the minimum level that it takes to get water into the pipe, and you make this level higher than the wall level at which water flows into the overflow chamber, then you most certainly could make the water level a little bit higher than if you had the pipe all the way down.

I have a Megaflow AGA 75g tank, and if I have the overflow pipe at its lowest setting, there is about 1/8" gap between the water level and the bottom of the tank's "oak" trim because the plastic Megaflow partition isn't quite high enough for my liking. I raise the pipe to make the water about 1/4" to 3/8" higher than its lowest point so that there is no slight gap between the water level and the oak trim or brace on the tank.

I will point out that doing this inhibits the ability of the Megaflow to skim surface water somewhat, but I'm willing to sacrifice this because I don't like the look of a 1/8" gap between the brace or trim on my tank and my water level. Ideally, I wish my Megaflow made the level of water in the tank 3/8" higher so that I could have my pipe at the lowest setting. This way I could skim the most surface water possible. But, beggers can't be choosers...

-Joe

[rdefino]

Is there any difference between the All Glass drain pipes and the Durso made pipes?

thanks

[schneijt]

Functionally I think they are pretty much the same. Looking at pictures from the Durso website, I think the only difference is that the Durso's aren't adjustable like the All-Glass kit is. You'd have to order (or DIY) a specific size of Durso, whereas the All-Glass could be used on different sized tanks by adjusting its height.

-Joe

[WaterssretaW]

So let me see if I understand...raising or lowering the drain pipe does NOT regulate water drainage? Meaning, there is no benefit to a higher or lower position besides water height?

[DodgeDude99]

correct, only thing lowering the pipe does is make it noisier, raising it up quiets the splashing into the overflow.
it can only drain as much water as it is being put into the tank.

[FishGuy5]

Here's another question- I have dual overflows in my 110 reef w/ built in dursos in the overflow. Both drains are on independent lines. One drain flows fine and the other drain with the longer "line" to travel drains very minimally where the water sits all the way up above the overflow. It barely drains at all. Is it because my tank is not level? Is it because that line has to travel horizontally for at least 3.5 feet before it drops into my sump. The one that works fine drops right into the sump. It's driving me nuts why the one line won't drain properly. TIA

[FishGuy5]

Also, the drain that is not working correctly-there is sucking or "gurgling" of air on that line. When flow is shut off, water stays filled to the top of that drain pipe. Really can't figure it out. Sorry to hi-jack.