first of all, read the "LED university" page on RAPID all the way through.
okay so definitely get the apex controller. I used the base Jr. unit and everything worked jsut fine. You will also need to add on the VDM module (Variable Dimming Module, which is basically a bridge between the apex, and the dimmable meanwell drivers. The VDM controls the amount of voltage that is allowed to travel to the LEDS. the higher the voltage applied the brighter the leds are. The VDM can go from 0v-10v. Basically in units of 10. Volt translates to percentage on. Whereas, 0v means leds are off, 1v= 10% max brightness. 10v=100% max brightness. You program the percentage you want via Apex Fusion, a program that allows the user to set IF & Then statements. Dont be intimidated, just read the manual and research on the forums for directions on programming, its fairly straight forward and easy to get a hold of if you put a little study time in.
Now for LEDS: Definitely buy dimmable, I would also suggest solderless so that you can change out your leds/colors easily in case you dont like the spectrum mixes you can get. I also recommend the predrilled heatsinks. Which allows for easy install, and again you can move the leds around later on if you want. Just go ahead and buy an assortment of extra solderless connection wires. Youll need them. and they are not very expensive.
Colors: Most DIY led'ers are using Cool Whites and Royal blues as the PRIMARY leds. These are two of the "original" (if you want to call it that) led colors that was available, and used widely in AI Sol Blues, and other early generation LED fixtures. Eventually more colors made their way into the market, because we want a "full spectrum" or as close to full as possible to mimic the sun, halide bulbs or t% (tried and true bulbs of reefings past).
I would recommend a ratio of 2:1 meaning for every 1 white (cool white, neutral white, warm white), you have 2 blues (royal blue (preferred), or Blue)
Your tank is a 29 gallon, so i would not go crazy with additional colors like: RED, Green, orange. (they have a tendency to "color Band" on small fixtures, and the spot in the circuit is better spent on an RB or B (royal blue, or blue). Color banding means when on you can see "columns" of light being projected down into the tank. Imagine a red spotlight at a concert, and then a green spotlight right next to it. You can typically see the "beam" of color light as it travels to the final "spot". This is bad in a tank. You want the light to blend as best you can.
Now for the drivers: Every light has a "jumper" or "driver" or "ballast". In the LED world its called a DRIVER. a Driver receives voltage from the outlet, and for lack of better term, "breaks it down" into usable voltage for the led to output light. You need to plan on having 1 Driver for each "daisy chain" of leds your planning. Drivers are rated to service a particular number of leds, too few leds on the "chain" and it wont light up, too many and it will also not light up. The Meanwell drivers are rated for 5-8 leds. you could maybe push 9 or 10 but dont quote me, and you run the risk of overheating the diode (resulting in much shorter lifespan)
chains or circuits of leds are called "channels". 1 Driver + 8 leds = 1 "White Channel" etc.
okay so now, pretend you have 2 strings of christmas lights on the floor. you want all your white leds, to be on one channel. and all your RB,B, UV to be on another separate channel. This way you can dim the white and or blue channels indepently, lower or higher to get the "Spectrum" you prefer or like within the display tank.
for your size tank id recommend about a total of about 16-20 leds. (if you can make them all fit on a heat sink). This will allow you grow most if not all type of coral in the tank. SPS included, because of the lid, the leds are close to the water surface. How you break that up into a color ratio is entirely up to you. Use mostly cool white, but throw in 1 or 2 neutral white (which brings some very very very faint hues of red and orange yellow, to help complete the spectrum) Dont get warm white. They are too red and will overpower all your color leds and make it look like ****. Get a bunch of RBs, maybe 1 blue, and 1 cyan (if you want to play around). Again, whites on one channel, colors on the other.
phew, okay thats a good start. Good luck and god speed. Do your research if you still need additional help. Theres tons and tons and tons of info on DIY leds here and on RC.
