He (Steve) is sure that his heat sinks are good.... may be if canopy is too tight there is not much air flow, thus it will be harder to keep low temp.
Anyway here is what he says.
Tubular Heat sinks are SUPERIOR!
http://stevesleds.com/Tubular_Heatsinks.html
This is one of the primary challenges with providing a proper heat sink for your LEDs -> Keeping them cool all while being lightweight and affordable. Generally, there are two mainly used heat sink styles, the plate-style heat sinks and the tube-style heat sinks.
Everyone has seen those old-fashioned "plate" heat sinks with fins sticking out on the back. I think that people currently use those because that is what they have always used and it seems to work ok. That is what their dad used, and their dad's dad used....you get the idea. Yes they do work just "ok" but that is it. Plate heat sinks are heavy and expensive and don't work as well compared to tubular heat sinks. You have high performance LEDs, why not get a high performance heat sink that costs less!
There are 4 properties that heat sinks need to be effective at dissipating (getting rid of) heat.
1) Thermal conductivity
2) Surface area
3) Air movement over that surface area
4) Affordability
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His tank with LED DIY fixture
http://stevesleds.com/Photos.html
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Cool White MSDS
http://stevesleds.com/uploads/Luxeon...eve_s_LEDS.pdf
Royal Blues MSDS
http://stevesleds.com/uploads/Luxeon...teves_LEDs.pdf
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