HMA posted this information in a different thread but I felt it best to also give it a sticky thread 
Thanks HMA!
Thanks HMA!
A very good idea fishead. Around my aspect somewhat more to describe here the translation of one of my reports to this topic. Like all my reports among other things to find on my web side.
UV-C and the sea water aquarium
I would like to point out my aspect in some sentences to the topic " UV-C and the sea water aquarium ".
What causes a UV-C light in an aquarium at all? Can it be in certain situations rather harmful and/or counter productive? Now, I would like to analyze these questions here a little more near.
Regards one the existing quantity of water of an aquarium more exactly, is immediately clear, that is really in no case with the living conditions of our animals in nature comparable. The water is however one of the most important factors for a healthy and nature near attitude of tropical fish and low animals in an aquarium. This artificial environment should of us, which we maintain animals in an aquarium, as nature near to be arranged as only at all possible. In addition we need a filtering as optimal as possible. But even the best biological and mechanical filtering the tremendously high number of possible unwanted micro organisms and parasites as well as viruses and bacteria from our aquariums will not be able to hold back. And here now the UV-C light is used. With its assistance it is possible the germination number in an aquarium on one, for the fish, well compatible measure to hold. Ultraviolet light helps us thus thereby, for in an aquarium living animals, to create a healthy "water climate".
What is that actually, ultraviolet light? Ultraviolet light are rays of light wich lie exactly in the electromagnetic spectrum between the not visible X-ray and the visible light for us humans. For the application in a UV-C lamp comes, in such a way specified, “low pressure mercury light". It is made of a particularly made glass, which the necessary spectrum of light, and/or light of a certain wavelength, lets through. The wavelength of the ultraviolet light is measured in "Ångstroem", the optimal necessary range for the targeted killing of the germs is exactly 2537 Ångstroem. This wavelength has the capability, everything this flash spectrum suspended bacteria, Viruses and micro organisms to kill and/or provide that they can not further increase. A further cell division and thus the further increase of the bacteria population with it successfully are prevented. Neither taste nor smell is affected; still any chemical reaction occurs in the aquarium water. Neither the chemical structure nor the pH values of the aquarium water are affected negatively. The usually positive bacteria film on the aquarium decoration and the sand remain, just as fish and low animals, uninfluenced by it.
In order to kill unwanted organisms in the aquarium is it necessarily these to a certain quantity and/or intensity of ultraviolet light to be exposed. The germ-killing effect of UV-C light is to be regarded thus in the relationship time and intensity of the irradiation. Like before already briefly mentions, causes the ultraviolet energy of the light a change of the DNA (deoxyribonucleic acid) of the illuminated organism, which entails that the organism can not further increase. The destruction of the unwanted organisms thus essentially depends on the flow rate of the aquarium water by the UV C light, not so much of the Watt strength of the light. The longer the retention time of the water in the lamp body is, the more highly the UV dose is and thus also the degree of the sterilization. With increasing flow rate the effect and/or sterilization decreases, therefore it is to be paid attention to as optimal a flow rate as possible. A too slow flow rate has however no negative effect on an optimal sterilization. An often asked question, is possible an overdosing of UV-C? This is to be answered with a clear NO. A further question often is, whether a higher Watt number of the UV C light in the relationship aquarium/pump affects itself negatively? Here again a clear NO is the answer, since water can not store UV C jets still transport. However none to strong pump should be used, since otherwise the period spent of the water in the UV C light is too small and thus no optimal sterilization can take place.
Mostly UV-C lights are built into the back cycle of the aquarium as bypass, thus between return pump (sump) and aquarium. I do not find this solution optimal, since the return pump thereby achievement becomes "branched". In my eyes it is a much better solution to use a small pump, the Watt number of the UV C light adapted, and to use a separate UV-C pump cycle in the sump. In a multi-part sump one takes the water for the UV-C in the last part (return pump) and leads it across the UV-C back into the first part (water intake). Since the pump for the UV-C light should have at least 2/3 less achievement than the return pump is guaranteed which one optimally sterilized. I prefer for a continuous operation (24/7 to 365 Days) this solution.
The following table shows in the rough relationship of aquarium size, Watt of the UV-C and optimal flow rate.
