Aquarium Technologies Borrowed from Other Industries

Actinic lighting was developed and used in other industries before reef aquariums

Actinic lighting was developed and used in other industries before reef aquariums

We marine aquarists use a variety of tools to help keep our tanks healthy by either changing or removing the waste products of the animals we keep. But did you know virtually all of the devices we use were originally designed for other industries?


For instance, ozone is a naturally forming gas found in our atmosphere that helps protect us from the damaging effects of the sun’s ultraviolet radiation. It was discovered in 1839 by Christian Friedrich Schönbein.

Ozone was originally used to purify drinking water and as a health-giving gas. Unfortunately, that health idea produced just the opposite result because the oxidizing effect we can use to purify certain things will also oxidize us, especially our lungs.

Ozone is formed by lightning and is merely an oxygen molecule with an extra electron. That extra electron is unstable and doesn’t want to stay spinning around that molecule, so it tries to escape. It can do that if it contacts another molecule, such as something organic. Then as it combines with that other molecule, both are destroyed or changed into something else. The only waste product is pure oxygen.

We use ozone in our skimmers to reduce organics and toxins, including hydrogen sulfides and toxins produced by bacteria or corals, to something harmless—or at least less harmful than the original molecule.

If I were using a deep sand bed, I would certainly use ozone because of its ability to remove hydrogen sulfide, which is very toxic and can be formed in a deep sand bed. If ozone is used in a skimmer, that changed molecule is now removed from the tank through oxidation, similar to what bleach does. The best part about using ozone is that it works without leaving anything in the water. Very cool stuff!

We make ozone for aquariums in a small ozone generator, which creates electrical sparks in a chamber where air is passing. This ozone-infused air is then pumped into a skimmer so that any organic molecule it touches is instantly oxidized. We use it in a skimmer so that the gas is “used up” before it enters the tank and oxidizes the fish. Many people run the effluent from their skimmer over carbon to remove any excess ozone. I don’t do that, but I do run it over a long trough over my tank to be assured no ozone remains.

We need to be careful that no “raw” ozone enters our homes. It will damage rubber and anything organic, including pictures of your mother-in-law, which should never be placed near an ozone generator. But if used correctly, ozone is a fantastic gas. I have used it continuously for 40 years, which virtually assures I have no photos of my mother-in-law in my home.

The protein skimmer

I mentioned “protein skimmers” above, but our protein skimmers actually don’t remove proteins and don’t skim anything. Their proper name is “foam fractionators.” They were originally used in the 1960s for wastewater purification. Before that, this technology was used in a very similar apparatus called a froth flotation device, which was used to separate valuable ores from less valuable ores.

The thing works because hydrophobic particles attach to the surface of bubbles to form a pneumatic (i.e. rising) foam. In this way, relatively hydrophobic particles can be separated from relatively hydrophilic particles. Froth flotation is typically used to separate coal particles from ash or particles of valuable minerals. Do we have to know that? No. We just need to know that skimmers produce foam and, as Tarzan and possibly a Neanderthal would say, “Foam bad!” The foam then overflows the reaction tube in the skimmer and is removed.

If you live near an ocean beach (and we all should strive for that), you may notice that on a particularly rough day, foam appears on the beach where the waves crash. If you do observe this, find a different beach because that foam comes from pollution, as pure water does not produce foam.

So skimmers are a really good thing to have in our tanks, and if we add ozone to them, they are even better. But resist the temptation to put the ozone-bearing hose up your nose to test for it. If you are still on speaking terms, call on an old girlfriend/boyfriend to do that for you.

Actinic lighting

Actinic lighting was originally used when photography was in its infancy (though they didn’t just take pictures of infants). However, the film they were using then was not exposed with actinic lights. Rather, it was used in darkrooms so the photographer could see while pictures developed in an otherwise pitch-dark room.

Actinic lighting was also used in hospitals to cure jaundice in infants. It still is. Sunlight will also cure jaundice, but hospitals frown on putting newborns, especially weak, premature, jaundiced infants, on a pigeon-infested roof top to get sunlight.

Actinic lighting, which is just light with a range of 420 nanometers, affects our outer layer of skin, forcing us to manufacture vitamin D. This is a good thing and is what babies (and all of us) need, as they used to be born outdoors and run around naked for most of their lives.

We aquarists use actinic lights in our tanks to make our lighting healthier to fish and corals. Just as sunlight is healthful to us, it is also healthful to shallow-water creatures, and the artificial lighting we normally use in our tanks is usually insufficient in the correct spectrum to be of any health benefit to corals.

Actinic lighting will cause corals to fluoresce, and it will not contribute to algae growth because plants do not use the blue wavelengths of visible light. Now, especially with LEDs, we are more interested in the colors of the corals and fish than we are in their health. Well, maybe not more interested, but we tend to like pretty things and get distracted by their beauty. Supermodels come to mind.

Reverse osmosis

Reverse osmosis is something most of us rely on now, as our tap water usually contains all sorts of things we don’t want in our tanks and the stuff the water companies use to purify water is fine for us but toxic to aquatic life. Our municipalities use chlorines to kill bacteria, but chlorines are bad for the creatures we are trying to keep. Also some tap water comes from deep wells and water in a well gets there by filtering down over thousands of years through layers of minerals, metals, old bicycles, dead raccoons, Oldsmobile fenders, Milli Vanilli tapes, and other stuff that we don’t want in our systems.

A few years ago I did a water change and almost immediately, my fish started to jump out and my corals wilted. I lost most of my livestock that day, including an 18-year-old cusk eel and a very old mandarin among others. I couldn’t figure out what happened until I called our water supplier and was informed that the town just added zinc orthophosphate to the water to control corrosion in the pipes. I am sure it also killed any corals and fish in the pipes. From that time on, I’ve relied on reverse osmosis and resins to purify my water.

Reverse osmosis is commonly used to remove salt from sea water and make it available for drinking. In 1977 Cape Coral, Florida became the first municipality in the United States to use the RO process on a large scale, with an initial operating capacity of 3 million gallons per day. By 1985, due to rapid population growth in Cape Coral, the city had the largest low-pressure reverse osmosis plant in the world, capable of producing 15 million gallons per day. The first reverse osmosis plants were much too slow to be used for much of anything except experimentation.

Reverse osmosis uses a membrane that has pores so tiny that only something the size of a water molecule or smaller can pass through. It is a little more complicated than that, but that is all we need to know. Before reverse osmosis, we all used tap water, which, as I said, had some problems.

Deionization resins

Deionization resins are used in industry to make pure water for many purposes, including pharmaceuticals. Deionization is a chemical process that uses specially manufactured ion-exchange resins, which exchange hydrogen and hydroxide ions for dissolved minerals and then recombine to form water. DI resins will remove just about everything that is left after we use reverse osmosis and will leave water as pure as it can be and perfect for our purposes. After the water is stripped of its minerals, we can then add only the minerals we want to produce a healthy aquarium.

Another interesting thing about deionized water is that it is a poor conductor of electricity, so it is used in the semiconductor industry…and for washing makeup off supermodels.


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About Paul Baldassano

Paul Baldassano has been in the hobby since the 50s and holds two aquarium-related patents. His current reef aquarium was set up in 1971. He is also an avid SCUBA diver and Vietnam veteran.


  1. Ha! Milli Vanilli tapes xD

  2. You make a comment that plants don’t need blue light. I would have to disagree with you on this point. Here is also an article on PAR that also discusses that blue light is needed for chlorophyll production.

    Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to the human eye. Photons at shorter wavelengths tend to be so energetic that they can be damaging to cells and tissues, but are mostly filtered out by the ozone layer in the stratosphere. Photons at longer wavelengths do not carry enough energy to allow photosynthesis to take place.

    Other living organisms, such as green bacteria, purple bacteria and Heliobacteria, can exploit solar light in slightly extended spectral regions, such as the near-infrared. These bacteria live in environments such as the bottom of stagnant ponds, sediment and ocean depths. Because of their pigments, they form colorful mats of green, red and purple.

    Chlorophyll, the most abundant plant pigment, is most efficient in capturing red and blue light.

    Accessory pigments such as carotenes and xanthophylls harvest some green light and pass it on to the photosynthetic process, but enough of the green wavelengths are reflected to give leaves their characteristic color. An exception to the predominance of chlorophyll is autumn, when chlorophyll is degraded (because it contains N and Mg) but the accessory pigments are not (because they only contain C, H and O) and remain in the leaf producing red, yellow and orange leaves.

    PAR measurement is used in agriculture, forestry and oceanography. One of the requirements for productive farmland is adequate PAR, so PAR is used to evaluate agricultural investment potential. PAR sensors stationed at various levels of the forest canopy measure the pattern of PAR availability and utilization. Photosynthetic rate and related parameters can be measured non-destructively using a photosynthesis system, and these instruments measure PAR and sometimes control PAR at set intensities. PAR measurements are also used to calculate the euphotic depth in the ocean.

  3. Ken, thank you for replying. I don’t remember where I referenced that about blue light and I just tried to find it, but instead I found about 10 articles that made my head spin as they all contradict each other. It seems (and I could be wrong) that green plants (and algae) do not use green light because it is the green color we see that is reflected off the plant and not used. But green is very close to blue so if it is a greenish blue light, the green part will be reflected off. If the algae is not totally green but more red, the red light is not used for plant growth. So you may be correct, but, but it is hard to tell in all instances such as depth and type of algae. But I will go by your link as it seems plausible until I can find where I found that one. Again, thanks for replying as I am not the God of lighting and could be totally wrong, or even in a coma.

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