With so many anecdotes and half-truths about what UV can and can’t do for our aquariums, we got in touch with a guy who designs and builds commercial UV sterilizers for a living. Michael Barrett is Head of Technical Development at Tropical Marine Centre and knows a thing or two about UV light.
Do you have any qualifications/experience in lighting?
我从大学毕业于计算机科学领域的电子产品。我的最终论文是基于轻疗法 - 特别是使用强光来治疗某些皮肤状况。从那时起，我被这个虫子咬了 - 我的主要兴趣是光的生物学（即它如何与生物体相互作用）。从那里，我成为一家照明组件公司的技术经理，该公司为TMC提供了用于消毒器的零件。在这个角色中，我帮助他们从磁性镇流器中移动到了电子镇流器，从而提高了整个范围的效率。几年后which later became known as AquaRay。在整个过程中，我一直通过与我们提供的许多企业和机构以及少数专业课程和研讨会的经验和讨论继续进行照明教育。现在，我在16年后担任技术开发负责人，努力确保我们在质量方面处于领先地位，同时继续提供产品，以使业余爱好负担得起且易于使用。
What’s the difference between a UV clarifier and a UV sterilizer?
这是一个重要的区别。澄清器的目标是控制和减少水寄水藻类，该藻类可使水清洁和清除以观看。它通常旨在提供较低的UV-C剂量率，并且通常比水族箱更多。消毒剂给出较高的剂量率，不仅针对藻类，而且针对细菌，病毒，真菌甚至一些寄生虫等病原体。紫外线治疗中最重要的概念是“接触时间”。这只是水与UV-C接触的时间，因此决定了剂量率。它可以分为三个变量：
- Flow rate – we all know that we need a relatively high flow in our aquariums. The faster the water is flowing, the less time it will be in contact with the UV-c, and so the dose rate will be lower.
- 反应堆室的尺寸 - UV-C被水相当快地吸收，因此所处理的水需要相对靠近灯以确保接触。这意味着较大的反应堆腔室的平均剂量率较低。
- Length of lamp arc – the lamp arc is the source of the UV-c light, and the longer that is, the longer the water will be in contact with the UV-c. The contact time can also be affected by the path of water flowing around that lamp.
灯泡的形状/样式很重要吗？
电弧长度将产生效果，形状也可能影响接触时间。这也将对设备的效率产生影响。在TMC，我们使用相当紧密的长灯，这意味着水在整个灯的整个长度上都紧密流动，因此您可以根据流量和灯长度确定接触时间。但是，还有其他一些设计，较大的腔室依赖于该腔室的流动减速，或者带有试图在灯周围旋转水长时间的单端灯。从理论上讲，这可以改善接触时间，但很难确定。
In UV does wattage matter i.e the more power the greater the kill rate?
Yes, it does. The power of UV light emitted is a direct contributor to the kill rate, along with the contact time. Generally speaking the more power, the more UV-c is available, however, we are talking about the power of UV-c specifically, which is the portion of light around 250-280nm emitted by the lamps that’s effective at killing microorganisms. This is not necessarily a direct relationship with the overall power of the lamp. So it may be possible to have a more power-hungry lamp that emits less UV-c. I would always advise buying a trusted brand to ensure efficiency.
In UV we talk about kill rates. What does that mean?
杀伤率等于某个物种的UV-C的致命剂量率。通常在平方厘米区域（µWS/cm2）中施加的功率量通常说明。
Everyone installs UVs on reef tanks primarily to kill Ich/Whitespot. Why does flow rate matter, and can any UV really kill Whitespot?
I get asked this question all the time! You can see from the chart that ich has a massively high kill rate compared to other pathogens. As we touched on earlier, reducing the flow rate can increase the dose and so people tend to lean towards this when targeting Ich. This theory is well founded, but the reality is that you’re unlikely to hit the dose rates needed to kill Whitespot. It is further compounded by the fact that the UV sterilizer can only kill organisms that pass through the reaction chamber, so the parasites can still remain on the fish and in other areas of the system. The better way to approach this is to see the UV as a control. It may not kill the Ich passing through, but it will deactivate those organisms meaning that the population is controlled and will wane over time. When paired with good husbandry and maintenance, the appearance of Ich can be eradicated in this way.
If you run a UV sterilizer on a bypass can it still be effective?
A UV can be run on a bypass, but the danger is that you create a semi-closed loop and you end up not treating all of your water. Ideally, your UV should be placed on the return – this ensures that water flowing back into your display is as clean as it can be and that the entire water volume is passing through the sterilizer.
What are the biggest mistakes people make when selecting an aquarium UV?
绝对了解所需的流速是一个问题。缓慢的流量可能会导致更高的杀伤率，但是您需要平衡两个主要元素，以达到系统的正确流速：
- If running on your return, you want to ensure enough flow for your mechanical and biological filtration among other things.
- 一些细菌迅速繁殖，每15-20分钟增加一次数字！这意味着理想情况下，您希望每小时至少3-4次将全部水量放在紫外线上。
这意味着我们通常的建议是坚持关闭entire system volume a minimumof 3-4 times an hour. If you really do require higher kill rates at that flow, then you should up your power. On a normal system you can be safe in the knowledge that at our recommended volumes and flow rates, your UV will still be working to control those other more complex pathogens such as Ich.
The other common mistake is the expectation that the water will be completely sterile and that UV is the cure to all problems (algae/parasites/bacterial blooms etc). This is just not the case. UV forms part of a well-maintained system by staying on top of potential infestations or bacterial blooms. It only treats what passes through the reaction chamber, but by doing so it helps to maintain a healthy environment for both the fish/reef keeper and the livestock alike.
What’s the difference/benefit between a quartz sleeve and a glass sleeve?
Quartz glass is often used for UV sterilizers and clarifiers both in the sleeve that separates the lamps from the water and the lamps themselves. This is because it has a high rate of transmittance of UV-c, meaning that more of the UV-c will get to the water to do its job. There are alternative specialist glass materials out there, which are significantly cheaper, but the quality of transmittance is not guaranteed. If buying glass lamps or sleeves I would check with the manufacturer. At TMC we use quartz sleeves. Our lamps are in fact glass; however we have carefully selected the glass used to have a sustained transmittance of over 90%, so you are getting good performance for a fraction of the price of a quartz equivalent.
Is it okay to touch the bulb when installing it?
When using high-pressure UV-c lamps (these ones tend to look like the metal halide bulbs of old), you most definitely should not touch the bulb. Dirt and grease from fingers can create hot spots when in operation and cause the lamp to explode. With the low-pressure lamps that we generally use in the hobby, it is less of an issue; however any contaminants will still potentially reduce the lamp life and transmittance, so it is good practice to wear some gloves when handling the glass parts.
如果我剂量液体有益细菌，紫外线会杀死它吗？
简而言之，是的；但是，只有当它通过紫外线。您在水族馆中想要的有益细菌通常会在永远不会看到您的紫外线灭菌器 - 诸如沙床，岩石工作和过滤介质之类的地方。我的建议是在给药后关闭一个小时左右的紫外线，以使细菌结算并开始殖民该区域。虽然不要忘记将其重新打开！！
紫外线有什么新功能？荧光灯单元有任何改进吗？
UV技术相同的for many years now – in the early 2000s there was a switch to electronic ballasts (the gear that runs the lamp), which made things more efficient; however, until recently things have stayed much the same. In the past 4 years,TMC has introduced its Titan range of sterilizerswhich adds the use of a photocatalytic lining to the reaction chamber. This lining interacts with the UV-c light to produce a perfectly safe and contained oxidizing effect in the water. This increases the effectiveness of the UV by a significant amount (around 30%) and has the further benefit of attacking and removing pollutants such as phenols, improving water clarity. Over the last year I have also been spending a lot of time in our dedicated research lab working on some improved lamp technology, so watch this space!!
我们已经讨论了很长时间，但领导紫外线灭菌器仍然暗示了我们。您是否认为我们会在短期/长期看到LED紫外线灭菌器？
我想这么想，这肯定是我关注的事情。那里有LED灭菌器，但它们还不适合爱好的需求。对于几乎不存在的流量，要么是低功率，要么寿命短，要么昂贵。不过，在这一领域正在进行大量研究，因此除非撞到砖墙，否则我希望在未来5年内看到更可行的解决方案。有很多设计注意事项（想想电源与接触时间），但我们确实喜欢挑战！除了在能源效率方面取得巨大飞跃的明显好处外，还应该有可能以一种全新的方式对我们的水族馆进行灭菌。
我们谈论礁石照明中的紫罗兰色和超紫罗兰色二极管。是真的紫外线吗？如果是这样，它会损害我们的眼睛吗？
Ultraviolet light ranges from wavelengths of 100 to 400nm. It is split into three classifications within that – UV-c (100-280nm), UV-b (280-315nm), and UV-a (315-400nm). The wavelength can be equated to energy – the shorter the wavelength, the higher the energy and so (broadly speaking) the more damage it can cause. The violet and ultraviolet LEDs used in reef lighting don’t go below around 390nm but are usually in the 400-420nm range. This is safe for human skin and is OK for eyes as long as they aren’t viewed directly because LEDs are a very intense source of light. When used normally, the light is too dispersed to cause any damage, but it should be noted that even blue LEDs can damage eyes if viewed directly. The human eye is not so sensitive to blue and violet light, and can’t see ultraviolet light at all, so with these wavelengths, it is possible to look at a very powerful energy source without having the need to blink or look away. For this reason, intense blue and violet LED sources that aren’t mixed alongside other colors should always have warning labels to advise against direct viewing.
