I tried searching, but couldn't find spacing or gap between LEDs and screen?

[chriswf]

Didn't want to have to make another post on this, but I couldn't find anywhere on how far back I should put my LEDs from the screen?
Just 3 inches? 6 inches?
3watt 660-670nm red LEDs, 1 445 blue.

ALSO, can I just put saran wrap over the front of the LEDs, and maybe glue the edges of the Saran wrap to the heat sink to water proof it?

[Floyd R Turbo]

If you want to waterproof them, you need to spray them with LED Seal

http://www.ledsupply.com/9013-07.php

Not saran wrap. Something thin like that would probably melt or start on fire. Even with LED Seal sprayed on, you're still going to get water & possibly salt creep on the LEDs though. A thin acrylic shield in front of the LEDs would be the way to go, you can just get a couple of spacers and make a stand-off.

But your original question of distance is really dependent on a few things, like how tightly the LEDs are grouped together, etc. I have mine 2" away with a diffuser at 1" and that seems to work well. Without the diffuser I would go another 2" away or more. After all of that, it is really dependent on growth patterns of the individual system.

[chriswf]

Hmmm... That's a tough one then.
Because, I can't really alter the positioning of the LEDs. The Thermal/Adhesive paste says the paste is pretty much permanent.

[Floyd R Turbo]

I mentioned spacing but then shifted to distance from screen.

As far as spacing goes, yes mine are 2" on center (reds) but if you did different then you just have to deal with it. Pics?

[chriswf]

Haven't done it yet.
I just got around to cutting my pipe. All my wires and LEDs are pretinned now.

My pipe cut isn't perfect, there's water coverage all over it but the flow isn't even.
I have a drilled pipe that I did good with, but when you drill, you lose height on the screen because the junction point brings it lower.

[Floyd R Turbo]

As the screen gets mature, the flow will even out.