18 Watt UV Bulb Review, for Turbo Twist 6X, more

 

Updated 2-23-16

I have already published articles/reviews earlier with the 9 Watt UV Bulbs and 13 Watt UV Bulbs commonly sold as replacements; either as not true hot cathode/low pressure lamps in the case of many 9 Watt lamps or with the incorrect base for many applications as in the 13 watt GX23 versus the 13 Watt G23.
In this review/article I will now look at another common UV Bulb that like the 9 watt in particular is often not what it seems; the 18 Watt G11 UV Replacement Bulb!!

9 Watt UV Bulb Review
13 Watt UV Bulb Review

In a market driven by price and "free shipping" the only way to deliver a so-called UV bulb at the prices offered is to sell the "medium pressure UV Bulb" as an implied "Hot Cathode, Low Pressure UV-C Bulb/Lamp", which NONE sold at prices much under $15 can be (especially when shipping is calculated in).
The cold hard facts are, NO business can exist selling a TRUE hot cathode, low pressure UV-C Bulb that has a cost of $13 OR MORE (out the door to the vendor) for this same price with shipping included!! Even at a retail price of $16- $20, a business would have to operate at a very low overhead and profit margin.

As well, although often difficult to find, the some 18 Watt G11 UV Replacement Bulbs use patented methods to lower operating temperature which increases the efficiency and UVC output.
Such as:

• Patented Metal Heat Reducing Technology
• Norman lamps super high efficiency HO/low heat UV Bulbs.

The patented heat reducing technology used by AAP/Norman UV Lamps help with these aspects of the UV Bulb:

• Lower operating temperatures which in turn increases energy directed as UVC (which is why you have a UV light in the first place). This 5° C difference increases efficiency about 5% or more, adding to the 75% improvement of these low pressure UV lamps over common lower cost medium pressure UV lamps/bulbs sold at online discounters and home improvement warehouses.
• Longer Life and higher output over the life of the lamp.
• Easier starts, which new hot cathode UV lamps are often difficult to start initially.

Please read these articles as to why only a low pressure, hot cathode bulb should EVER be used in your Aquarium UV Sterilizer, Pond UV Sterilizer/Clarifier, or Air UVC Purifier:

• Actual UV-C Emission from a UV Bulb; Aquarium or Pond
• 254 nm Hot Cathode low pressure UV Bulb
• UV Lamps, Bulb; How they work
• UV Sterilization; Facts & Information

Simply put; these commonly sold, medium pressure bulbs at 7% germicidal 254nm UVC simply cannot destroy the bacteria or maintain aquatic Redox at any useful/normal flow rate when compared to the high UVC output hot cathode UV-C Replacement Lamps.
Basically these bulbs are only good for clarification and then only at lower flow rates than a low pressure UV Bulb

This is not to say that these higher output are not easy to find, as they can be found, you simply have to be willing to pay a bit more (often with sale prices high quality UV-C Bulbs/Lamps not that much more too). Several manufacturers/distributors such as American Aquarium Products, Purely, & Phillips all sell ONLY hot cathode, low pressure, Higher Output 254 nm UV Bulbs.

See this link for High Quality UV-C Bulbs/Lamps

See the graph below for a comparison of these two UV Bulbs types



As the graph shows, the low pressure UV bulb has its energy spike primarily in the optimum UVC range, however the medium pressure UV light has several spikes, admittedly including some in the optimum range, which is why these bulbs can still get away with calling themselves 254 nm germicidal bulbs, when in reality only small percentage of their energy output is in this important UVC range.

The bottom line is do NOT let Google, eBay, Amazon, etc. guide you to one of these many websites selling these mostly useless medium pressure UV Bulbs that produce little UVC necessary for an effective UV Sterilizer or Purifier.
Spend a little more and purchase a American Aquarium, Purely, or Phillips 18 Watt Bulb, which often still only sell for $16 to $30 online.

American Aquarium Products hot cathode/low pressure 18 Watt is sold near cost as a promotional item and is THE true hot cathode 18 Watt UV Bulb to purchase for both quality & price!!
See:
18 Watt UV Bulb from American Aquarium

Please also read this article:
UV Lamps, Bulbs; How they work, Coatings, more

Please reference this unique, in depth, & researched article that is IMPERATIVE READING for anyone interested in moving from basic aquarium or pond keeping to more advanced aquarium or pond keeping:

Aquarium or Pond UV Sterilization, Correct Sterilizer Use

By Steven Wright with input from Carl Strohmeyer-PAMR