can I use 10w x 6 led
Because it is to. easy install
What color and k
Should be use
And
If I use small led w3 can I use aluminum and fan for cooler led . Because the heatsink expensive in Charge Because its heavy
And what color and types and k should be use
This is a very subjective and personal issue. If you have a fair amount of royal blue and neutral to cool white, the lights will grow corals. Other colors UV/violet (400-420nm), hyperviolet (430 nm), blue (475-485 nm), cyan (496-505 nm), lime (570 nm) help to bring out specific colors and increase growth of some corals. Some people (and vendors) argue for high K white (15000-20000K) but I think that these days, many are coming back to a mixture of cool white (6500K) and neutral white (~5000K).
I built my first LED from a RapidLED kit that had 12 royal blue and 12 cool white to go on a 24g Nanocube with failed lights. This worked well enough, but the corals did not pop and I found that the blue channel needed to be run 3x higher than the whites to please my eye. This used dimmable drivers controlled by a manual dimmer switch. Not ideal, but functional.
My 2nd build over a 30" deep 75g corner tank the following mix (4 x 400 nm semi-LED, 4 x 410-420 nm semi LED, 4 x 420-430 NM semi LED, 9 x Luxeon ES 440-465 nm royal blue, 18 Cree XT-E 450-465 nm royal blue, 9 Cree XP-G2 6000k neutral white, 2 Cree XP-E Photo red (650-670 nm) and 2 Cree XP-E green (520-535 nm) all put on a 20" heat sink from RapidLED with a 4 channel Storm controller. This worked, but grew some more algae than I liked. Since then I have switched out the reds for XP-E blues, the greens for lime and half of the cool whites with neutral white. I like this better. This tank is in a rebuild/rescape phase but corals and anemones are doing well. These use 60 degree optics and some "disco ball" effects can be seen on the sand bed and rocks, but not so bad.
My 3rd build for a 150g (60 x 24 x 24) planned to use the "Dream Chip" that was written about a lot on another forum in a long thread. I won't bore you with all of the headaches I encountered, in part due to my own designs and partly due to defective chips. I decided to replace these with BlueAcro Acrostar 20K Blue Pro pucks with reflectors and diffusers on a 48" Makers heat sink, and flanked this by 2 x 80W T5 retrofits on either side. I like this quite a bit and it was very easy to install, wire, etc. It is a bit too blue/purple for my taste when only the LEDs are on and the light is not spread out enough, but the light mixing is quite good and there is no disco effect. I bought 3 more of these chips and 4 x LumiLeds neutral white COB LEDs that I will install one of these days. The T5s draw at least double the current of the LEDs as they are currently set.
You should consider whether you want one large heat sink or several small ones that might be more available and less costly. The Makers heat sinks are very nice, but so are the ones that RapidLED sells (and no doubt others). Fans are built in. Whether you use small 10 or 20w clusters is a matter of choice. You can buy these fairly cheaply on the internet from Chinese vendors. Overall, your most cost-effective option is probably to buy a couple of 165w "black box" LED units but this will not give you the quality or satisfaction of selecting chips yourself and assembling.
