AN ARTICLE ON OZONE I THOUGHT WOULD BE OF INTEREST TO SOME
ARTICLE by Dr. Rivers
There are two reasons to consider using an ozonizer. The first is to oxidize organics in the water, keeping it more pure and with a higher redox value. The second reason that is becoming more in vogue is to attempt to kill parasites by the same oxidation.
There have been really no detailed scientific studies of the utility of ozone for parasite control. I have observed little beneficial result when trying ozone for parasite control in my previous home tanks, nor in a shop I used to consult for. I have also observed little benefit in trying to use ozone to control hair algae, as well.
However, it has been studied in water purification, mostly in freshwater aquaria and wastewater treatment applications. For aquaria water purification there are only two ways to use ozone. The simplest way is to inject a very low dosage of ozone into a protein skimmer to change the chemical characteristics of the organics in the skimmer reaction collumn to improve organic removal by the skimmer. This involves using low dosages of 2.5-10 or 15 mg/hr of ozone. If your ozonizer does not have a mg/hour setting on it, you won't be able to use this method.
Also, the ozonization of the organics in the skimmer reaction collumn will lead to production of a wetter, lighter color product of smaller volume. With a smaller amount of ozone used with this method, it is not mandatory to consider flowing the water exiting the skimmer over a good activated carbon to remove residual ozone. It is good to somehow have the top of the skimmer's air effulent pass through activated carbon so persons in the room are not exposed to ozone in the air. However, with this smaller amount of ozone it is not mandatory.
Many factors contribute to the actual ozone load in the water of both a skimmer, ozone reactor, and display tank. It is very difficult to calculate what the exact dosage resulting is. With the lower dosage into a skimmer method, it is unlikely that the overall tank redox level will rise, and/or excessive ozone will accumulate in the water. This can be checked for with a residual ozone test kit. Greater water purification can be acheived with introduction of higher ozone levels into a skimmer, or more efficiently with an ozone reactor, to elevate the tank redox level.
Ozone persists in saltwater with a halflife of about 1-2 days. Excessive ozone leads to chronic gill damage and epithelial irritation in fish, and may be negative for invertebrates. Therefore, the safest way to use ozone at higher levels is with a good redox controller. The controller is set to turn the ozonizer on at a low setpoint (I typically use 250 or 300) and turn it off at a high setpoint (I typically use 400, 450 max). Be aware that for this type of setup, you need a quality redox controller and probe (somewhat expensive), with replacement of probe annually with probe cleaning and calibration at least every 2-3 months.
It is possible to try to use higher dosage of ozone injection without using a redox controller in view of the expense. Martin Moe's book Marine Aquarium Reference gives suggested dosages in mg/hr per tank size and when to double-check with residual ozone test kit on a trial and error basis. Recently, some hobbyists have also started turning the ozone unit on at various dosages for 1/2 to 1 hour per day with a timer, without a controller, using the concept of 24-48 hrs for half-life of ozone introduced. I have no experience with these less expensive methods of using a higher dosage of ozone to elevate tank redox. I have either used a small amount of ozone periodically in a skimmer, or I have used a redox controller.
Within the last two years I actually have completely abandoned the use of ozone. Since there is no scientific documentation of utility in marine parasite infection, and I can maintain adequate water purity based on redox levels with a good skimmer and good activated carbon, I no longer use it.
Be aware that you need ozone resistant tubing (silicone or even better, special neoprene-type tubing). Also, humidity can decrease ozone production in air-gap spark ozone generators with premature unit failure due to corrosion of unit internals. This means that if you are in area of high humidity, to maximize unit ozone production and unit lifespan you would need an air drier device in line with the ozone generator. ( dust also has the same effect).
Bill Rivers, DVM, PhD, DACVR
ARTICLE by Dr. Rivers
There are two reasons to consider using an ozonizer. The first is to oxidize organics in the water, keeping it more pure and with a higher redox value. The second reason that is becoming more in vogue is to attempt to kill parasites by the same oxidation.
There have been really no detailed scientific studies of the utility of ozone for parasite control. I have observed little beneficial result when trying ozone for parasite control in my previous home tanks, nor in a shop I used to consult for. I have also observed little benefit in trying to use ozone to control hair algae, as well.
However, it has been studied in water purification, mostly in freshwater aquaria and wastewater treatment applications. For aquaria water purification there are only two ways to use ozone. The simplest way is to inject a very low dosage of ozone into a protein skimmer to change the chemical characteristics of the organics in the skimmer reaction collumn to improve organic removal by the skimmer. This involves using low dosages of 2.5-10 or 15 mg/hr of ozone. If your ozonizer does not have a mg/hour setting on it, you won't be able to use this method.
Also, the ozonization of the organics in the skimmer reaction collumn will lead to production of a wetter, lighter color product of smaller volume. With a smaller amount of ozone used with this method, it is not mandatory to consider flowing the water exiting the skimmer over a good activated carbon to remove residual ozone. It is good to somehow have the top of the skimmer's air effulent pass through activated carbon so persons in the room are not exposed to ozone in the air. However, with this smaller amount of ozone it is not mandatory.
Many factors contribute to the actual ozone load in the water of both a skimmer, ozone reactor, and display tank. It is very difficult to calculate what the exact dosage resulting is. With the lower dosage into a skimmer method, it is unlikely that the overall tank redox level will rise, and/or excessive ozone will accumulate in the water. This can be checked for with a residual ozone test kit. Greater water purification can be acheived with introduction of higher ozone levels into a skimmer, or more efficiently with an ozone reactor, to elevate the tank redox level.
Ozone persists in saltwater with a halflife of about 1-2 days. Excessive ozone leads to chronic gill damage and epithelial irritation in fish, and may be negative for invertebrates. Therefore, the safest way to use ozone at higher levels is with a good redox controller. The controller is set to turn the ozonizer on at a low setpoint (I typically use 250 or 300) and turn it off at a high setpoint (I typically use 400, 450 max). Be aware that for this type of setup, you need a quality redox controller and probe (somewhat expensive), with replacement of probe annually with probe cleaning and calibration at least every 2-3 months.
It is possible to try to use higher dosage of ozone injection without using a redox controller in view of the expense. Martin Moe's book Marine Aquarium Reference gives suggested dosages in mg/hr per tank size and when to double-check with residual ozone test kit on a trial and error basis. Recently, some hobbyists have also started turning the ozone unit on at various dosages for 1/2 to 1 hour per day with a timer, without a controller, using the concept of 24-48 hrs for half-life of ozone introduced. I have no experience with these less expensive methods of using a higher dosage of ozone to elevate tank redox. I have either used a small amount of ozone periodically in a skimmer, or I have used a redox controller.
Within the last two years I actually have completely abandoned the use of ozone. Since there is no scientific documentation of utility in marine parasite infection, and I can maintain adequate water purity based on redox levels with a good skimmer and good activated carbon, I no longer use it.
Be aware that you need ozone resistant tubing (silicone or even better, special neoprene-type tubing). Also, humidity can decrease ozone production in air-gap spark ozone generators with premature unit failure due to corrosion of unit internals. This means that if you are in area of high humidity, to maximize unit ozone production and unit lifespan you would need an air drier device in line with the ozone generator. ( dust also has the same effect).
Bill Rivers, DVM, PhD, DACVR
