Durso standpipe construction

[Anonymous]

I've been looking at his website, and Durso actually will sell you one of these things for $15 to $20, but I would rather just make it.

However, I have some dumb questions.

I bought a 100 gallon long. It has an overflow that is approximately 5.5 x 5.5 " square on the inside. There is a circular hole in the center at the bottom that is 1.75" in diameter.

What size bulkhead do I need to buy for this? Durso conveniently lists some bulkheads on his site too. The 1" bulkhead says "Suggested hole size: 1 3/4 inches." Is that bulkhead inside diameter going to be big enough?

Can I buy a bulkhead at a hardware store? I can't find one at my local Ace hardware.

Is the bulkhead or the overflow likely to be limiting the water flow? I have 36 ca. 0.125" wide, 1" long slots in this overflow, but I assume that the water will only be about 0.25" to 0.5" above the line for the slots.

So, 36 * 0.125 * 0.5 = 2.25 in^2 for the overflow, vs 3.14 * ( 0.5 * 1.0 )^2 = 0.785 in^2 for the bulkhead cross section.

On the other hand, there is a lot of surface contact with the overflow comb, so in reality that flow might be less.

What's a recommended bulkhead inside diameter for a 100 gallon?

 

[Anonymous]

Ace does have some nylon bulkhead for small application, but they are not good for most people. Get some bulkhead from a reef hardware place, or your LFS may have some in stock.

Different style of bulkhead need different diameter. Make sure the bulkhead you get will fit in the 1.75 hole you got.

The cross section is very approxm due to the fricture of the wall on laminar flow. one 2X2 pipe with square x-section will carries more water than four 1X1 ones. You mentioned the idea, so I am sure you are familiar with it.

As you know, it is the water height behind the overflow or the height of water inside the overflow chamber that affect the flow rate. For 100 gal, I think 1 inch bulkhead should be fine. I would go for two 1 inch, or one 1.25, but that will involve additional drilling, and it may be fine the way it is. (depends on your flow need.)

 

[Anonymous]

Thanks. I'll stick with the 1". It will be an improvement over my last overflow, since I did not have one. The returns won't be my only source of water movement.

 

[trido]

With the 1" durso you should get a gravity feed of 600GPH through the overflow. Most of us forget that we can only get X amount of flow through our sumps and baffles before we are sucking micro bubbles into the tank.

As you said, One 1" overflow is more than you had last time around. You hopefully will have a nice big 55G sump/fuge . I believe you ordered a submersible enheim and about 600GPH of return will make a baffle system easier sinceyou wont have a river running through it.
The standpipe itself is very easy to build. 20 minutes tops. You will be in the middle of plumbing anyway.

 

[Anonymous]

Standpipe is in, pump is hooked up, and as soon as the glue is dry (tomorrow?) on the return assembly, I will test it for leaks. The Enhiem I bought is rated for 900 gallons/hr but it has to pump up 5 feet, the flow splits in a T, and then each pipe does a 90 back into the tank and then goes through further restricting/redirecting devices, so maybe 600 is a realistic estimate. It would be kind of funny if I overdid it with the pump.

Since I had to order the bulkhead, I just got everything for the standpipe from Richard Durso ($15.95 for standpipe, $6.50 for threaded bulkhead, $20 shipping, LOL), so this gives me some confidence that the damn thing will work right. The standpipe is 1.25"; the bulkhead is 1" inside diam. The overflow is too small to house two; in fact the box is too small to house the next size up street-L.

 

[Anonymous]

Oh, by the way, is there any difference between the white and black pipe? The black stuff looked more robust and matched the trim of the tank, so I built the return with that.

 

[Anonymous]

You can tell what pressure are they rated for by looking at the schedule number, but if it i s not stamped, you can pretty much guess by looking at the thickness of the wall. Thicker the wall, the better, but the price you pay is higher cost, and smaller diameter for the fluid.

 

[Anonymous]

I thought you were gonna kick my arse for buying the overflow standpipe from Durso.

8O