PVC "Guide"
*Disclaimer*
While this is intended to be a step by step guide on the use of PVC, this post will only reflect my setup. Your setup may be different and your situation may require different equipment or a different configuration than what I'm using. Please take my words as a grain of salt among the many experienced hobbyists who have been doing PVC for years longer than I.
Step-by-Step Guide to hard plumbing a reef tank with PVC
Step one: your tank
Purpose - This first step will analyze what kind of tank you have, if it can be drilled or came reef ready, and include some pre planning.
My tank came "reef ready", meaning there was an overflow installed in a back corner and the tank came drilled for 1" and 3/4" bulkheads. The bulkheads that came with the tank were slip x slip, however the underside where the PVC would have been glued had been made so that a person could slip tubing over the bulkhead and held in place with a clasp or clamp. This did not serve my purposes well so I had to buy new bulkheads. If your tank did not come drilled, you can have a lfs drill it for you for fairly cheap or you can do it yourself if you feel confident in your ability. There are many videos on YouTube showing this process so I won't include that here.
A note on bulkheads: bulkheads come in all shapes and sizes. For the purposes of my setup I needed to find bulkheads that were slip x slip so as to glue the bulkhead and PVC tuning together. There are two kinds of bulkheads commonly available, the reef ready tanks have the holes drilled close together and require a thin abs bulkhead. If I could have drilled the tank I would have spaced the holes farther apart and used the meatier bulkheads that use the thicker plastic. A common problem with the thin abs bulkheads is that they are prone to cracking if over tightened.
I bought new bulkheads at brs, they were the only place I could find bulkheads that would fit my purpose for plumbing. This was the only piece of equipment I could not find at lowes/Home Depot, plumbing stores, ace, and pool supply stores.
Step two: plan, plan, plan
I was always taught that when working in a project 1/3 of your time was spent planning, 1/3 spent building, and 1/3 spent finishing.
Purpose - during step two you will draw out the setup showing every Union, glue spot, PVC length, angle, etc.
For my setup I decided to stick with the 1" PVC as my tank drain and the 3/4" PVC as my return. This is glued to the bulkheads using abs to PVC glue (many choose to use PVC glue here but I wanted to do this by the book for the first time). The PVC comes from the bulkhead 6" down to a union (if you wanted to use different PVC you could use a compression pipe which would allow you to go from the bulkhead PVC diameter to any other sized diameter you wanted to use). The 6" drop is to leave room for a hack saw to be used in the event of a bulkhead cracking, needing to move the tank, etc. By using a union I don't have to redo the entire plumbing and can simply unscrew it from itself. I used 45* angles instead of 90* to relieve some head pressure put on the return pump. I also used unions wherever I could as this allows me to dismantle and clean any section or replace any section needed. I should note here that I put a t in my return to feed back to my sump as my return pump is a little too powerful for my overflow and was causing a major waterfall through the tines. I then added a ball valve to the t so I could control how much water would come back to the sump, I would have liked to use a gate valve to better tune this but wanted to stick with what I could easily find local at the hardware store.
Step three: gather your supplies
I found everything I needed at lowes for less than $50 and bought the bulkheads from brs; Vinyl tubing alone would have cost at least $30 plus clamps/clasps.
NOTE: I would encourage buying new bulkheads if this was a used tank. I've had multiple tanks that have had cracked bulkheads, gaskets that dried out and weren't sealing, etc., and most of the time I end up buying new bulkheads anyways after a few hrs working in the ones that it came with. If you are using used bulkheads made sure to clean the rings where the nut threads on.
Bulkheads for comparison showing the slip tubing connection common on reef ready tanks vs the slip x slip bulkhead used for PVC (note: I have four bulkheads and tried cutting off the slip tubing part, the diameter inside was too small to slip PVC inside and I had to buy the new ones pictured alongside the old ones)
PVC glue and primer combo pack (black/purple) and abs glue (green):
Step four: assembly
Purpose: to build the layout for your plumbing.
I started with the bulkheads and worked my way down from there. This seemed logical and there's really no other reason for doing it this way other than it just seemed like a good idea.
NOTE: the gasket on the bulkhead goes tank side. This creates a seal INSIDE the tank and not underneath the tank. While many will call foul and say it doesn't matter, it does. If the gasket seal is on top of the glass inside the tank then the water pressure will push down onto the seal making an even better seal; if the gasket is under the tank then the water will push past the glass down onto the gasket and while you can tighten the nut all you want you will stand a good chance of leaking from this point because it can never truly be tight enough, hence the need for a gasket inside the tank. The nut then goes on the underside and you tighten it till its hand tight. I always use a wrench (or you can find bulkhead wrenches) and tighten it 1/4 turn past hand tight. Any tighter than that and I've found the abs thin walled bulkheads tend to crack about a year in from the pressure that the nut puts on them from being over tight. This is just my expensive though and hand tight may be tight enough.
Here's a video on using unions from brs TV:
http://youtu.be/ikd_DeE9tY0
I haven't a clue honestly cause they're right side up on the phone.
