Showing posts with label UV Sterilizer. Show all posts
Showing posts with label UV Sterilizer. Show all posts


Saltwater Aquariums With No UV STERILIZER Equals Certain Troubles

I am shocked and surprised how often I come across marine aquariums (reef or fish only) that have no U.V. sterilizer filter. These aquarists are playing Russian roulette with their aquariums, running the risk of being vulnerable to a parasite outbreak.

A low pressure mercury vapor discharge tube fl...
A low pressure mercury vapor discharge tube floods the inside of a hood with shortwave UV light when not in use, sterilizing microbiological contaminants from irradiated surfaces.
(Photo credit: 

There are many different situations that can cause a disease and/or parasite outbreak in your marine aquarium. It could be adding new fish, or perhaps one of your fish changes sex and throws off the entire pecking order, or a fish dies or is removed and that throws off the pecking order; or say your chiller (if you have one) went on the fritz during a heat wave - and the list goes on.

And given that there are so many situations that could spark a disease or parasite outbreak, wouldn't you want to protect yourself (and your fish) against this likely possibility? Who wouldn't? And yet many aquarists don't have a U.V. sterilizer on their system. It's like rolling the dice and crossing your fingers, hoping you don't have a disease outbreak.

So, before I go any further, let me just say that - yes - you definitely need a U.V. sterilizer. That is, if you want your fish to live for years rather than months, and if you want to avoid even the possibility of a total system meltdown (scary scientific term). Yes, this is my opinion, but it is also backed up with over 11 years in keeping saltwater fish (primarily reef tanks) with only three disease outbreaks - and two of them were caused by human error. By disease outbreak, I mean multiple fish dying from parasite infestation. This is attributed to aggressive use of U.V. sterilizer filters. And don't forget, I'm not talking about just one tank. I run a high-end custom aquarium design, installation and maintenance business, where we service many customers with large saltwater aquariums.

So, yes, it's a bold statement. And it also happens to be true. See - I don't like problems or surprises when it comes to aquariums. Over the years of running my business, I have had to develop ways of preventing problems from even being able to happen on our customer's tanks; and then having designed the system to be prepared to accommodate the problem if it ever does happen. This is sort of our company philosophy to aquarium system design and it is a preventative approach designed to prevent problems - so that we put far less energy into reacting to and fixing problems. Any way - enough of that. Back to U.V. sterilization.

By now, you might be thinking "yeah right - I don't believe you". Well, I'm not saying that we've only seen parasites on some of our fish three times in 11 years. NOPE. We see low-levels of parasites on fish fairly often - but those fish are thriving and healthy and live long lives - typically for over five years, and are able to fight off the parasites. AND the parasites are not aloud to bloom to dangerous levels because the U.V. sterilizer kills the parasites when they are water born (verses dormant in the substrate) and looking for a host.

So, what is a U.V. sterilizer filter? The U.V. stands for ultraviolet sterilization. Basically, it contains a special light bulb which emits U.V. "C" light. U.V. "C" is the band of U.V. light that gives us sun burn. So, essentially, a U.V. sterilizer filter is "sun-burning-to-death" (scientific term) or sterilizing your aquarium water as it passes through the filter, and thus killing any water-born parasites. It runs 24/7 and is very cheap to operate and can PREVENT parasite outbreaks. What aquarist wouldn't want to be able to prevent a parasite outbreak? This is why having a U.V. is a no brainer MUST HAVE filter for your aquarium.

In addition, the U.V. filter will prevent bacteria blooms (caused by water-born bacteria - milky or cloudy water) and phytoplankton blooms (cause of green water). The result here is clear water. Of course, this doesn't remove the underlying cause of the bacteria bloom (excess organics and insufficient bio-filtration) which must still be dealt with.

Sizing is probably the most important factor when selecting your U.V. sterilizer for your aquarium. My general advice is to slightly oversize your U.V.. Most sizing charts are based on aquarium/system volume. The last thing you want is an undersized U.V., because then it is almost useless (i.e. it is too small to prevent disease outbreaks). Several parameters to consider are system/tank volume, water flow rate through the U.V. filter, and bio-load (how much life is in your tank). So again, when selecting your U.V. sterilizer, choose the next one up in size, as recommended on the sizing chart.

Example: If your aquarium is 100 gallons and the sizing chart recommends a 30watt UV for a 90g and a 40watt UV for a 120g, then go with the 40watt UV.

One of the primary criteria used in sizing a U.V. sterilizer is the water flow rate through the unit. See, if you send too much water (too high of a flow rate) through too small of a unit, then it won't be effective in killing the parasites. But for me (I'm lazy), that is too much work, calculating flow rates, etc., so what I do is take the manufacturers recommended sizing for my aquarium (gallons) and then choose the next larger size U.V.. This almost ensures that your U.V. will be effective in killing water-born parasites in your aquarium and preventing a disease outbreak. And nine times out of ten, if you do the calculations of water flow rate, UV kill rate, and total system volume, you will end up at the same size U.V. any way. One caviat here - this method is based on average bio-loading (average number of fish/invertebrates etc.) for any given tank volume. So if you are crazy aggressive with your stocking density of fish/corals/invertebrates/etc., then you may even want to choose a U.V. that is two sizes up.

Of course, U.V. is not the only effective way to sterilize against disease and parasites. Ozone is very effective if applied and monitored properly. But Ozone is far less forgiving than U.V., and while you cannot CAUSE any problems by over sizing a U.V. filter, you can cause BIG PROBLEMS by improperly applying and monitoring ozone. But more about ozone in future posts. For now, suffice it to say that U.V. is very safe and simple to apply to your aquarium filtration system, and there is no monitoring (unlike ozone).

You do need to ensure proper upkeep or maintenance of your U.V. sterilizer. Once a year, you must change the bulb and the O-ring and/or gasket, and clean off the quartz sleeve (housing the bulb). This may take 30 minutes to an hour to do, but is necessary because after a year of operation, the bulb has begun to lose its potency and the ozone gas produced by some U.V. bulbs will break down the O-ring and/or gaskets that seal off the quartz sleeve. And in some systems the quartz sleeve can accumulate mineral deposits that may reduce effectiveness of the U.V. bulb. A simple overnight vinegar bath and wipe-down with a sponge will do the trick.

Generally, I'm not big on having opinions. I like to be open-minded, and opinions tend to cut us off from being open to learning something new. But when something works as well and as consistently as this does, well, I feel strongly about it. The proof is in the pudding, as they say. I hope this is of help to you.