250W DE has the same intensity as 400W SE?

[AlfaRomeo]

Hi guys, issit true that the intensity of 250w DE is roughly equivalent to a 400W SE? And Is mogul type referring to SE also? kinda confused liao.. hehe

[SharkBait]

Based on Sanjay's test, it definitely seems so but i think he did the test without the shield on the DE bulbs. With the UV shield, i think the intensity is reduced greatly.Mogul is SE.

[AlfaRomeo]

So i guess its more economical to run 250w DE than 400w SE than.. I am sure the UV shield cant affect it that much rite? Can even get the 14k DE bulbs if you wanna more blueish outlook?

[BarraCudaTM]

you will be surprised how much intensity can be reflected and absorbed by the tempered glass

[Achilles Tang]

250w and 400w are two very different animals.

DE vs SE - the debate still rages but it does seem that SE bulbs do produce dangerous amounts of UV that is extremely damaging to corals and livestock without the UV shield.

Hon has DE bulbs that seems to be burning his SPS corals even with the UV shield on. I think there must be something strangely wrong with his UV glass shield.

[AlfaRomeo]

and tis not advisable to run them without the UV shield rite? but isnt it documented somewhere that UV will cause the SPS corals to develop colorful pigments? just need to wear lead shielding whenever we are the tank only. hehehehe

[SharkBait]

250w and 400w are two very different animals.

DE vs SE - the debate still rages but it does seem that SE bulbs do produce dangerous amounts of UV that is extremely damaging to corals and livestock without the UV shield.

Hon has SE bulbs that seems to be burning his SPS corals even with the UV shield on. I think there must be something strangely wrong with his UV glass shield.

AT, you sure those are SE?

[Achilles Tang]

DE are supposedly more efficiently designed... with regards to your question... 400w have greater depth penetration compared to 250w.

[Achilles Tang]

AT, you sure those are SE?

Huh? Oh. I edited it already when I saw your post.

I always type too fast!

[Achilles Tang]

and tis not advisable to run them without the UV shield rite? but isnt it documented somewhere that UV will cause the SPS corals to develop colorful pigments? just need to wear lead shielding whenever we are the tank only. hehehehe

Too much and you will see tissue fly off the coral skeleton....

Ever heard of an instant meltdown?

Robe, our senior reefer, once told us he removed his UV shield when he ran DE bulbs for only about 15 to 20 minutes and his corals bleached instantly/melted.

[Coral_ClamS]

so do SE also need UV shields?

nvr see that often for SE!

[SharkBait]

so do SE also need UV shields?

nvr see that often for SE!

The outer casing of SE bulbs acts as a UV shield

[Hon]

Well...My "branded" glass shield dun seem to block the UV well for my 250w DE. Much of my acro are sun burnt to the core and died. After moving the bulb 14inch away from the water surface, its seem to help....

But then, a new LCK acro at mid tank just got its tips burnt off again

[AlfaRomeo]

Hon , which branded lights set did u get?

[Hon]

Hon , which branded lights set did u get?

Giese**** ... lor

[AlfaRomeo]

Wah, so branded also still problematic har? did u write to them and ask for advise?

[Hon]

I wrote to them for a crack shield after 3mths of use.,,they no replace me also...have to pay SGD$70 to get a new piece

[pospeh]

The intensity of 400W SE is more than 250W DE.

But the thing is, just because there is more intensity does not necessarily mean that more "light" is getting into your tank. The light output is spread around a 360 degree circle, and you need a good reflector to direct the light going upwards DOWNWARDS to your tank. So the differance between a good reflector and no reflector at all can mean a 100% differance in the amount of light getting into the tank.

A DE bulb is much more compact compared to a SE bulb, so it is easier to build reflectors that maximize the amount of light directed into the tank.

Furthermore, DE bulbs are almost always identical in that the center of the plasma chamber is always in the same location vis-a-vis the DE holders. So the reflector designer know exactly where to place the reflector to maximize the amount of light getting into the tank. This is the reason why you see branded commercial DE pendants, but hardly any branded commercial SE pendants.

With the SE bulbs, the center of the plasma reaction chamber is located differently in different brands of bulbs. Hence, SE users have to make do with building their own pendants, and getting their own reflectors, and trying to be as effiecient as possible in reflecting the light into the tank.

There was an article in Advanced Aqualist by Richard Harker that compared the light getting into the tank as between factory-build commerical DE pendants vs. SE reflectors (i.e, Spiderlights). Generally, he found that DE reflectors directed more light into the tank such that a 250W DE bulb is roughly equivalent to a 400W SE bulb.

There a some very good SE reflectors that reflects as well as the DE reflectors, but I dont believe they are available here in Singapore.

So the difference is really the DE reflector, not the bulbs themselves.

BTW, I use the AB DE pendant set, and so far had no problems after 4+ years of use.