RDWC Parts List
Ok...
Here is a list of parts and potential suppliers for the RDWC.
There are 4 main parts to the system: buckets, pvc, uniseals, and equipment.
Buckets
I wasn't really sure what size buckets to get - for these types of systems you can find everything from 1 gallon to 10 gallon buckets. My design goal was to easily fit into a 6' tent. I also had a plan to raise 8 in veg and then flower 4 - picking the best ones to continue. So I wanted eight buckets in a 4x4 tent. So the biggest buckets that will fit into a 4x4x6 tent are 4 gallons. Square buckets works much better with the uniseals and for fitting into the tent. So I went with square, 4 gallon plastic pails. I would have preferred food grade, but I would not have been able to get black. I went with black and gave up on food grade.
These buckets are available from this supplier:
Affordable Buckets - 4 gallon square pail and lid
This company shows a very expensive shipping price on his web site. I called him to ask some questions and by the end of the conversation he offered free shipping on the buckets - a large savings over the price listed on the web site. So if you are interested, call them up and bullshit with them - they seem to be a good guys. They may even offer you the same deal.
I would order twice the number of buckets you think you are going to need. I screwed one up in the build - and you need some to store plants in while doing maintenance.
Uniseals
In my mind, the next most important item are the bulkheads. You can buy bulkheads at Lowes, etc - if you restrict yourself to 1.5". But they are very expensive (I think around $15 locally). I believe that these would work better and install easier than the uniseals... but honestly I have never had a leak installing the uniseals.
2" Uniseals are mostly used, it seems, by large salt water aquariums. And there are hundreds of places online that sell this type of equipment - very popular it seems in Florida here in the US.
PVC
All of my PVC comes from my local Lowes. The major issue I was thinking about was size on this one. Your goal is to push X amount of water around the system every hour. But the plants don't like a strong flow. So there is a balance here. Most of the commercial systems use 2" piping and it is available and still relatively cheap locally. So that is what I used. For the 8 bucket system, it took less than 15 feet.
You will also need fittings to put together the system. Most of these systems just sell you a length of pipe which has been rounded on both ends. They are so hard to push into the uniseals that I destroyed a bucket and two uniseals before I decided that sucked and gave up. They do have this teflon stuff that is both an initial "grease" and then a sealant. But then I tended to push the damn things in way to far - they would resist until they gave, and then slide a long way before I could back off the pressure. Now we were pulling the pipe back out of the damn bucket and trying to get it exactly x" apart. Not fun in my book.
So I found these 2" fittings that are designed for drainage systems - they have a male and female connector. The female end is designed to connect to a 2" pipe and is 3/4" long - exactly perfect for the Uniseal. When you grease these up with the magic lube, they slide till they hit the collar and are then exactly right for a very tight seal. Each of these fittings were $1.50 at Lowes and you need 4 of them for each two buckets that you connect. So Bucket->Uniseal->Female Adaptor->Male Adaptor->PVC Pipe->Male Adaptor->Female Adaptor->Uniseal->Bucket. So I build however many of these PVC pieces I need, install one end in the uniseal, and then push the other bucket onto the other end. Very easy. You will need to use PVC Pipe Thread on the male / female connection.
On the last connection in the chain - where I hook up a 1" inline pump - I use a different type of connection. This is a Bushing or Adaptor - can't remember which it is called - but it is designed to be connected to a 2" PVC pipe and has a reduction down to a 1" threaded pipe. Using the same technique as before, this slides right into the uniseal. I attach a barbed hose fitting to this... one inch suction hose... and connect to my pump.
I also put in 2" Solvent Unions - available from Lowes. These allow me to break apart the system for cleaning and moving around. Very handy for installation into a tent. But they are optional, you can do it without them.
Everything else is just PVC Corners, Tees, and ordinary connections - all available at Lowes. You can see all of them in my Photo Gallery.
Equipment
This is where it gets expensive. You need a very good, reliable water pump. You need very good, reliable air pumps, I am torn on appropriate airstones - but you need one per bucket,
For the water pump...
Most of the commercial systems I have seen target 7 turns per hour. What does this mean? They want to move all of the liquid in the system around 7 times. So if you are using 9 four gallon buckets and various connections - you will end up right at 34 gallons if the level is filled right below a 6" net pot.
This implies that in my system I need to move 7 x 34 gallons of water every hour. So I need a pump that moves at least 240 GPH.
Some people say that you need as much as 20 turns per hour. If I do this math, then I have 20 x 34 = 600 gph.
I also wanted to veg in this system - and to touch the bottom of a smaller 3" net pot I needed 40 gallons. So in this scenario, my system needs to be able to handle 20 x 40 = 800 GPH. That is starting to get to be a big pump.
So I settled on a 600gph pump - a little too much for my normal needs, and not enough if I am vegging. This is also why I stuck with 2" PVC - you can barely see the water moving, even at this kind of turn rate.
I have to admit that this pump is quiet and draws very little power for the amount of water that it moves. However, the same fitting on both pumps cracked, flooded my basement (an exaggeration, but I cleaned up a lot of water), and had to be replaced. The first one... I can take the blame on. The second one I treated like a marshmallow and it still broke in the same way while testing the system.
I fixed them both with PVC glue I had lying around and got new ones from the manufacturer. I won't reinstall the new ones because they are identical to the ones that I fixed. Aquavita needs to fix this.
Air Pumps and Airstones
Air pumps were a relatively easy decision. I needed 8 air stones. I was going to purchase the round aquarium stones that i always use... but was talked into purchasing a couple of the micro-pore design ones. After testing, the micro pore require more maintenance, and seem better for the plants. You can easily save money and go with the normal round aquarium airstones at PetSmart - I needed 6" for the buckets and they cost less than $15 each. I even found some cheaper ones online for under $10. The micro-pore design are $30.
Your decision on this one. For my second system, I went with the micro-pore design and I am very happy with them.
Which leaves just the airpump. You need a good airpump. The Dual Diaphragm Air Pump from GH will provide enough umph for all 8 aquarium stones.
However, if you want to drive the micro-pore design stones - you need more than this. I also wanted a small insurance policy in case an air pump quit. So I bought two of these pumps, each of which drives four air stones. I have so much air in my water that it "pops" when it enters the reservoir. I can turn one off - and the system still functions correctly.
I think that is everything important - if I have missed something, or someone has a better supplier - feel free to jump in here.
