Understanding UV

The use of ultraviolet sterilization is very common in the world of marine aquariums and ponds, but less so in freshwater aquariums. This being said, there are many salient benefits to utilizing this technology in sweetwater as you pond managers well know. There are very few ways to reduce pathogen transfer that work better than this perfectly safe and well tested technology. It is also extremely effective at clarifying water, giving your display a shiny, dime bright appearance!

So, what is ultraviolet (UV) sterilization? In short, it is using a specific wavelength of light to kill off suspended (free floating) organisms in the aquarium (or pond). Water is pushed through a container, past a bulb producing an ultraviolet wavelength of light. Primarily, the light doesn't actually kill the organism, but given ample contact time and penetration, this results in organisms being mutated in such a way as to make them unable to reproduce, and thus the population of said organisms' crashes. UV light can work this way on bacteria and viruses, brighter lights or longer contact time (or both) will similarly affect larger organisms like algae, fungi and protozoans.

Removing infectious agents from the water vastly reduces the amount of transfer of the vast majority of illnesses that can happen to fish in the home aquarium. UV sterilization is not a panacea for disease elimination. Used by itself, it will not cure fish that are already infected with some type of malady, though it is very effective at stopping the transfer of whatever they have to other fish. Also, fish that aren't stressed and well fed will generally have good enough immune systems to recover from most common illnesses and the UV can help prevent them from being re-infected once they do.

The water clearing effects of using UV sterilization are stunning. When used correctly, by wiping out the suspended algae and bacteria, the water in your display (or pond) can go from a murky mess to a crystalline palace in 24 to 48 hours in many cases. This clearing effect is enhanced by a secondary aspect of UV sterilization that isn't understood well by most hobbyists, called redox. In its most simplistic terms, redox is a measurement of the potential for an atom to gain (reduction) or lose (oxidation) an electron. Aquarium water with a high redox potential can pull electrons from bacteria and algae, killing them and removing them from suspension. The benefit of a well sized UV sterilization unit is that it can balance the redox potential of your aquarium water without any chance of harmful effects on your other tank inhabitants. Aquarium water with a good redox potential is cleaner, clearer and healthier for fish and plants than aquariums skewed one way or another.

All of these miraculous sounding results are real but are dependent on correctly utilizing whatever sterilization unit you choose. We at Aquatropic offer our retail partners a quality line of UV sterilizers for both ponds and tanks from Tropical Marine Centre and V2 (as well as parts, replacement bulbs and knowledge). The most important parts of getting UV sterilization right are wattage and contact time. Simply put, this means water has to travel at the correct speed, past the wattage of bulb that can do the job in the amount of time that it takes the water to pass through the unit. All the units we sell do not include pumps, and a pump with the correct flow, or a flow that is adjustable to the unit is imperative to correct use.

If you are planning to use your ultraviolet sterilization unit in conjunction with your return pump (in sump filtration), or in-line with your canister pump, it is of vital importance to match the flow speed of the pump (or canister) with the acceptable flow rate of the UV unit. This number will be clearly visible in the marketing material of any UV you purchase. For example, the V2 Vecton 400 has a maximum flow rate of 350 gallons per hour (gph). As long as your return flow is less than that, you will get full sterilization and balanced redox out of it. Simple! If you are utilizing sump style filtration (which is a little rarer on the freshwater side of the aquarium hobby) and your return pump is too strong, you will need to buy a secondary pump to move water through the UV unit and return this water to the sump. Do not plumb this secondary pump to return water to the aquarium directly, as you can overload your return drain and thus make a very large puddle next to your tank! For those of you with bigger tank needs, the V2 Vecton 600 can take up to 550 gallons per hour! If you need even more flow, you should start shopping our selection of Pond rated UV Sterilizers, even if it's for your aquarium.

Can I over sterilize? If you were using an ozonator (another article, and really only used on the marine side) or had a marine tank, this would be possible / more likely. Sterilization units don't differentiate between beneficial bacteria and algae and the ones more detrimental to our hobby. This being said, in all your freshwater tanks, this will not be a problem for you.

In the end, one of the easiest, and safest ways to maintain crystal clear water, and excellent redox potential in all your tanks is a UV unit, and they have our highest recommendation. Your guests will ooh and ahh over the brilliantly clean tank you keep, and your fish will be happier and healthier. There's even some research to indicate that plants grow better in tanks with clearer water and more balanced redox potential! Maintenance is easy, just turn off the unit and clean the bulb every couple water changes and replace the bulb every six months. If you're ready for the clearest, healthiest tank you can achieve, have your Local Fish Store call us here at Aquatropic today!