Luv, this is the setup that I run, works out pretty well for me, check out my thread, Girl Scout Cookies RDWC Scrog Grow. Essentially it's a 4 site, one res / control bucket, recirculating dwc system, built it from scratch. You could propbably build the same setup I've got going for around $375-$400 including the nutra-dip tri-meter which you will definitely need if you're serious about having a top quality setup. Obvioulsy that number does not include the reflector or other hardware that you will need but simply reflects the RDWC system itself. That being said, $400 is nothing compared to what you would pay for an undercurrent system from current culture (check their website out, it'll give you some good DIY ideas, cch2o.com). As you can see in the picture, I do not have an auxilary reservoir that tops off the system as the water is depleted. Would it make things a little bit easier, maybe, but I don't find that it's very difficult to top of the control bucket every few days or so. Let me give you a little run down of how the system works.
All the buckets are connected to one another via 2" pvc pipes. The point is to create a continuous circuit of pipes to allow flow through each of the buckets leading from and finishing back at the control bucket. Start at the control and work your way around the circuit unitl you arrive back at the control. In each hole you create in the buckets for the pipes to go into (3" holes for 2" uniseals) you will insert a 2" uniseal, basically a large rubber grommet to keep the water from leaking out. You can buy uniseals everywhere online, shop around and get a good deal, for the 2" ones they are about $5 a piece, kinda pricey but you get what you pay for and you really need them for such large holes. Now you can't really see it in the picture, but on the left side of the system, in the middle of the connection between the first row of buckets and the second row, you will place a pvc tee that has a 1/2 or 3/4" threaded outlet (whichever size your pump is designed for) to allow you to screw in a threaded bard which will attach to a return water line. This return water line is subsequently connected to a water pump, I use a dannaher mag-drive 250 GPH pump (around $60 or so), connect the water return tube from the pvc tee to the pump inlet, and then attach another piece of tubing to the outlet of the pump which is then run back to the control bucket. What this does is constantly recirculate the entire nutrient solution throughout the system. Water flows through the buckets, gets sucked from the water return tube by the water pump and is deposited back in the control thus perpetuating the flow of water and nutrients. After you get it all setup, there's really very little maintenance involved, essentially making sure that the control is kept at whatever water level you prefer to run your system at, which needless to say, can be avoided by connecting a reservoir to the control. Me personally, I wouldn't worry about the res, having to do daily top offs really lets you get to know your plants better and on top of that, if you fuck up your nutrient mix and your plants burn, then you're gonna have to swap out all your solution and that's just a huge waste of money. Anyway, I hope this helps a little bit, if you decide to build a system like mine, let me know, I'll do my best to help ya out! Here's a few before and after pics for ya. You should think about doin a Scrog, little bit more involved but well worth the extra time and effort spent.
