Today I worked on my first actual plumbing project for my new tank: the standpipes!
Standpipes are, well, pipes. And they sit in the overflow box and act as intakes for the flow down into the sump. There are lots of reasons to use standpipes, but for me, there are basically two: I want better control over the amount of water that can flow down into the sump in the event of a power outage or just turning off the pump, and also I want to limit the amount of waterfall/flushing noise generated by my overflow.
It's possible to set up a tank like mine without standpipes at all. I could just put an intake strainer much like that found on any number of filters over the drain holes in the overflow, and leave it at that. But if I did that, then I would lose the two benefits of standpipes I listed above. If the power went out or if I turned off the pump, the entire volume of the overflow box would drain down into my sump, and it's a pretty big overflow box. I am going to leave room in my sump for the extra water that happens in these cases (and if you make a sump, that is a must do), but I still would like to limit this fluctuation if I can. In addition, without a pipe that drains from near the top of the overflow box, the water level could be anywhere in the box depending on flow rates and other factors. This means the water could be falling over a foot to get to the water level of the overflow box, which could be rather loud. And also, sometimes this kind of setup can lead to flushing/draining noises that are separate from the noise of the water falling into the box.
So... standpipes. They're a good thing. The ones I decided to make are called Durso standpipes, after a smart dude named Durso. I based my pipes off of the instructions found here. I really like the fact that while this guy sells his standpipes, he also gives you good instructions for building them yourself if you want to. The neat thing about a Durso standpipe is that the pipe itself curves back downward at the top, so the water intake is always below the water level in the overflow box. This makes for a very quiet overflow!
Here is my pile of supplies for this venture. I need two standpipes because I have two drains in my overflow:
These are the supplies for my standpipes. A variety of fittings, some pipe, some PVC cement and primer, and some PVC cutters.
The first thing I did was cut connecting pieces of PVC so I could put all of my fittings together. After I did that, I had an assortment of parts that looked like this: (gloves are an awesome idea for PVC cement & primer)
One set from top to bottom includes:
A 1 1/4" PVC Cap
A small bit of connecting 1 1/4" PVC
A 1 1/4" Street Elbow and Tee
Space for the long pipe
A 1 1/4" Coupling
A 1 1/4" to 1" Reducer Bushing
A small bit of connecting 1" PVC
The standpipes glue together in three parts. There is the base and the pipe itself (in this picture I had not yet cut them to the height I wanted):
Then there is the top intake assembly, including the elbow and the tee:
And then the caps go on top. The three pieces are separate because it allows for easier adjustment and maintenance. Here's what they look like together!
And finally, this is what they look like installed in my overflow box. (My apologies for the darkness.)
This is awesome progress, but they're not done yet! Tune in soon to see the exciting conclusion of this story, including the drilling of many holes and the application of camouflage! Also, find out what the heck that cap is for!
An interesting thing I learned while completing this project: The dimensions you buy PVC under (the diameter measurements) sometimes have only a little to do with the actual measured dimensions of the piece. Some of them are just approximations. Neat. Kinda. Just don't assume an inch is an inch is an inch. Everything is bigger than you'd think.