Green Your Reef!
by
, 01-28-2010 at 12:23 AM (3409 Views)
PlumbingThe last thing I thought I would ever want to talk about was plumbing, but never say never. After my first couple of setups it became apparent that the plumbing department...was lagging. Thankfully, I stumbled across a local club with a very active forum that had tons of simple, practical information that demystified reefkeeping. Plumbing was definitely one of them. I really took for granted what my entire water volume had to do to pass through to complete a cycle from display, to sump and back up to the display. So after my failures I'm still learning, but I'll try to pass on a few points I picked up on plumbing a reef system, with efficiency and cost savings in mind.
Oversize Your Plumbing
The first may be known by many, but it bears repeating. Oversize your plumbing when possible. The benefit is minimizing frictional losses (drag) within the pipe and letting a pump, namely your return, pump more water. You would think that a wider return pipe, pumping vertically, would have more water pressure because there's more water in a wider pipe. Not so according to a Hydraulics expert in the Boston Area. It's the height that's pumped that's the most important factor. For optimal pump performance, especially under conditions such as returns and closed loops, you would want to match your target velocity with the appropriately sized pipe. Under sizing your piping essentially restricts optimal pump flow. Imagine a pump output with a ball valve on it stuck at 80% capacity. Here's two of the best threads I've seen on hydraulics, the first a simple explanation and the second is a table to determine target velocity for a given diameter pipe...First and Second.
Avoid 90 degree angles!
Bad Plumbing (2003), sculpture by Stephen Adams
Custom Bent PVC Pipe
When planning a run of plumbing for your system, try to avoid 90 degree turns/bends. Where under sizing is a restriction in flow, a 90 degree turn increases friction/turbulence and thereby impedes flow. This can be minimized several ways. The simplest method is using a flexible hose, braid reinforced flexible PVC tubing or spa-flex are the most common. The clear braided version is easier to work with and requires only plastic hose clamps, spa-flex requires PVC primer and sealer, and due to it's stiffness it can be hard to use in connections where space is tight. Both work well, but price per foot add up quickly for both. The last solution, is one of my favorites, custom PVC bending. Custom bending lets you set your pipe runs for long sloping turns and avoiding right angle turns and minimize the use of couples and fittings. There's a "proper" way to do it with a $190 heat blanket, which does reduce the PVC off-gassing. There's also a way to do it with a pack/camp stove, that's what I'll describe.
Materials Needed: Pack or camp stove, desired length of PVC pipe, sand or gravel, thick rag towel and duct tape
Start by drawing the shape your going to bend, measure out where the bends are and which way the bend will go, maybe draw a template. Tape one end of the PVC pipe with duct tape securely. Next, fill the pipe with sand or gravel to it maximum capacity. After filling, tap the pipe firmly on the ground to pack the sand/gravel, striking the side of the pipe, working it in a upwards fashion will help pack it densely. Give yourself a few minutes to do this, a dense pack prevents "wrinkles" when bending, and it's looks better when your done. After packing, top the pipe off with sand and tape off the last end of the pipe. Start up your stove outside(!), making sure to follow the appropriate safety precautions. Setup the stove, so the wind is over your shoulder, this will carry any fumes released by the heat away from you. Lower the taped off pipe over the flame keeping the pipe above the flame, not in it. You'll want to heat up the PVC to bend not melt it. Once your over the flame, start rolling the pipe in the flame, slowly bringing the pipe through the flame to cover the area to be bent. Do not stop rolling and moving the pipe. After about several minutes, you'll notice the pipe has begun to have some floppiness to it, continue warming the pipe. Once your area is heated enough, you will be able to bend the PVC to shape. I like to bring the pipe in the area that needs the bent pipe and bend it in place or use your template that's already drawn out. Once I have the shape I want, I make a mad dash to running water to cool and set the pipe (it helps to have a friend on hand). Recheck the bend, you might have to adjust. The plastic will heat somewhat more readily. It's pretty straight forward, and if I've missed anything there's a few videos on Google and YouTube detailing the process.
Uniseals
The next plumbing item saved my butt, and it cost all of $1.50 at my local plumbing warehouse. It's called a Uniseal and it's an alternative to using rigid plastic bulkheads that's been overlooked. Slick, simple and cheap. The uniseal is fitted into a standard sized hole, then the PVC is slipped through the gasket. There is no tightening as there is no nut and bolt assembly, withstands upwards of 1500 psi and fits flush against the hole. The small down side is most seals found are standard measurements, metric hole sizes (like All Glass Aquariums bulkhead holes) are hard to find.
I've missed quiet a few, but I'll save them for later, especially educators and penductors.