double ended mh bulbs vs screw in type

[Samw]

Originally Posted by BrainVat

But within a given brand, it's most often the case that DE bulbs produce more light than SE at the same wattage. This is the case with XM lights and also true for Sun Aquatics lights with the exception of the 10k series.

Try formulating intra-brand comparisons with sanjay's data to verify that this is true.
http://www.reeflightinginfo.arvixe.com/select2lamp.php

By this data, the myth seems to be that the "rule" for DE vs SE is true for all bulbs in all cases. More accurately, it is a simple general guideline for a given brand name that has some exceptions.

Here are some random comparisons of same color bulbs from same manufacturers using same ballast. It shows that SE is significantly brighter. I can go on but this is time consuming. The first one is from your own link. It doesn't look like the DE is brighter as you say it is when I look at that same graph. And in most of these graphs, the DE isn't even shielded. Once you shield them (like they normally are), the PPFD goes down even more. So, it looks like for the same brand and color, SE bulbs are brighter than DE bulbs in general with a few exceptions.








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