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Originally Posted by Casey
... in fact you stand a better chance of bleaching things with hqis than moguls it is easier to buy Moguls local here than HQIS also Moguls are cheaper and I have had both the difference in brightness is not that much ...
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yup.
In addition, even the most efficient transmission glass, 100% clean and no spray accumulation (because you clean the glass every day...
) still almost drops PAR transmission down to the PAR level that a good Iwasaki bulb setup provides. Sanjay's last study with 250W DE bulbs vs. Single end bulbs in a ballast driver comparison (
http://www.advancedaquarist.com/issu...02/feature.htm ) demo's that the highest PAR value came from a proprietary HQI Cap and Coil starter (PFO) driving 10kK DE HQI (Ushio bulb) setups, and was closely trailed by the SE
Iwasaki bulbs on Icecaps, BUT when glass shielding for the DE bulb setups was included, There is less than 10% difference between the two (and both are higher PAR than most other setups and more than adequate), sooooo... I guess it depends on whether you like spending your money on overkill or not.
Keep in mind that high temps and excessive UV radiation levels are suspected to be the major triggers for bleaching events in stony corals. Sudden changes in intensity may trigger these zooxanthallae-dumping events alone, so any changes you make will require a gradual acclimatization to the new intensity levels. This is true even when changing from year old bulbs to new bulbs. Several methods for this, either by increasing the distance between the new bulbs and the water, starting with a short (3 hr) photoperiod and increasing by 15 minutes every day until reaching your desired photoperiod, the use of multiple layers of fiberglass screening between the bulbs and the surface of the tank (start with 3 or 4 and remove one layer each 5 to 7 days), or a combination of these methods.
I might also mention that while in Atlanta, Sanjay brought out that his studies show extended useful PAR life for MH bulbs using electronic ballasts (some up to 2 years...)
Bottom line is that there is the real potential for damaging your captive
coral specimens, and in doing so you can end up spending money for items that are unnecessary. In view of the dwindling availability of cheap electricity in many parts of the country, and the added cost of heating and cooling the tanks and aquarium rooms to remove heat generated by such lighting methods, it would be both smart and prudent for you to consider fitting the needs of the corals into the proper perspective for our need to acquire "the best" (I am guilty as charged, it takes time to get there...
hth, I almost spent a ton of cash to change over to all HQI DE setups a few months ago, but after researching the topic, I decided to go with a combination of the 10kK SE unshielded bulbs on Icecaps HQI ballasts (for efficiency, not to drive HQI bulbs) for the displays, and stick with 6.5kK Iwasaki bulbs on Icecaps for the propagation systems.
