Please Explain This

[plasmadrive]

Mega tree usage not withstanding, you will get color shift on all white even on a 5m 30 LED per meter strip. I did a lot of testing on those and injecting at both ends will help maintain color and brightness much better. Otherwise you can get a very cool white at the beginning of the strip and almost warm white toward the end.

Personally I use DC-DC converters at the strip and feed those with 24v. This year I am trying out some 12v strips. Others have said they can put over 5 meters with no color shift. We shall see.

 

[i13]

I agree with the opinions of others here just saying to power at both ends of the strip if voltage drop is a problem (you'll need to cut the positive line in the middle of each strip). You could double the height of the tree by doing this and DC-DC converters are an option.

If that's absolutely not an option then the INK1003 strips have less voltage drop but they're more expensive
30LEDs per metre:
http://www.aliexpress.com/store/product/5m-DC12V-INK1003-led-pixel-srip-IP68-30pcs-1002led-5050-RGB-with-bulit-in-INK1003-IC/701799_1546255452.html
60 LEDs per metre:
http://www.aliexpress.com/store/product/5m-DC12V-INK1003-led-pixel-srip-IP68-60pcs-1002led-5050-RGB-with-bulit-in-INK1003-IC/701799_1546163504.html

I also recommend 30 LEDs per metre because that's still extremely bright and you can have more metres of strip without injection.

Adding to AussiePhil's post on current draw, it is always best to measure the actual current draw because it's usually less than calculated/listed on AliExpress.

Also you need to find out more about controllers. Every pixel is three channels so don't (for example) buy a DC controller that has 24 channels assuming it can control 24 pixel strips. You need something with E1.31 input and 2811 output.

 

[Gilrock]

My pixel tree is 5V WS2811 nodes. I run 168 nodes per output and I do one power injection after 84 pixels. I once tested one output with no power injection out of curiosity and everything looked fine until about 3/4's of the way through the 3rd column before I noticed dimming. So that was about 115 pixels so I've always used about 100 pixels as my rule for injection.