Our DYI LED lights offer the same or better LUX than a 400 watt Metal Halide and great colour. Some say that the spectrum is not there for growth but we disagree. Our frag tanks have seen exceptional growth with 
a mix 
of 107 Lumen Q-5 Cool-White and Royal-Blue Cree XR-E Star LEDs (Click here for more info on cree-xre). To be safe we recommend two T5s for every LED to ensure a proper spectrum. This in our research has given exceptional results on growth and colour in our office SPS tank.
We now offer build kits with the same LEDs we use in our display tanks. We built several LED lights including those using the LuxDrive 100omA Buckpuck with the Cree XR-E Star LEDs. The Buckpucks work but require a separate power DC supply. Also we experienced a few failures using these. The simpler and more cost effictive way we found is to go with the Mean Well LPC-35-700. It can drive 12 Cree LEDs instead of six. It also does not need a separate DC power supply. The only down side to this driver is its power. We tested two LEDs with it and it fried them. The LuxDrive 1000 mA Buckpuck with a seperate power supply would not have done that. Ensure you have at least LEDs in series before you power up this driver.
We started 
our build with a heat sink from Heatsink USA. They have numerous sizes available and apparently have been selling many for this specific application. The one w
e chose was the 7.280 Profile 30 Inch for $65. Your first step is to mark out where you want your LEDs on the heat sink . We chose 4 rows 2″ apart. We used a contractors pencil and ruler to mark the heat sink. Then your next step it to lay out your LEDs. Be careful not to mix them up as they all look alike. A Cree Cool White looks exactly the same as a Royal Blue LED. LEDs generate heat but not nearly as much asd a T5 or Metal Halide. We secured our LEDs using Arctic Silver Premium Thermal Adhesive. This thermal adhesive allows the heat from the LED to conduct to the heat sink with a very high efficiency. Arctic Silver is a two part epoxy and is mix in a 1:1 ratio. The cure time will vary depending on temperature but you should have good 5 minutes to work with at normal room temperature. We mixed 1/4 of the tube at a time and that was perfect for 12 LEDs or one row on our build. Using their mixing tool place a small amount on the back of the LED. You only need enough to produce a thin layer over the entire back. Then place the led on the heat sink with enough pressure to spread the adhesive evenly. Make sure you place the LEDs with the + side next to the – side as they will be wired in series. We let ours cure 1 hour before soldering.
When 
you solder use a quality soldering iron like the Weller WES51 and a led free rosin core solder. 
We used 18 gauge wire for an underground sprinkler. Solder the LEDs in series with the wire connecting the positive (+) side of the LED to the negative (-) side of the next LED. Do this with 12 LEDs if your using the Mean Well LPC-35-700. once you have 12 LEDs in series connect the red V+ wire to the + side of the LED. The black V- wire is then connected to the – side of the LED. W soldered a long wire to each end of the LED string so we could remotely place the driver on top of the heat sink. If you decide to use a 1000mA Buckpuck with a seperate DC power supply only wire 6 LEDs in series. We found that the Mean Well driver preformed better than the Buckpuck. Also we had numerous failures using the Buckpucks. Click on this link for a LED project using the Buckpucks and a separate DC power supply. RC DIY LED
We used a standard two prong ungrounded plug from Home Depot. Connect the ACN (blue) wire to the larger prong and connect the ACL (brown) to the smaller 
prong. The larger one is the neutral and the smaller one is the live or hot wire. Once your driver is connected test it out by plugging it in. If your LEDs dont light you might have a bad solder connection. Out of the 24 connections only one has to be bad for the whole string not to work.
After everything is connected snap on the lenses. You may want to use a small bit of silicon adhesive. The lenses come in different angles. We used an 80 degree lens to get the maximum coverage. The LEDs should last 11 years or longer. However heat will shorten their useful life span. We used a standard AC fan from Radio Shack to cool the heat sink and prolong the life of the LEDs. The unit we built cost just under $600 and produces the same Lux as a 400 watt Metal Halide light. With the fan total watts are 180. A 400 watt Metal Halide is over 450 excluding the heat and chiller costs. Metal Halide bulbs cost between $60 and $100. In bulb replacement alone this is a worthy project. With all thing considered we feel that the return on investment (ROI) is 4-5 years depending on which MH Bulbs you use. Below are some of our Tank Pics using these lights and an other DYI LED build we did.Click here to purchase a LED Build Kit.
