ich . . . the perfect storm, and Ozone!

[quack]

large tank and 8 years experience. Have had very small problems with ich before . . . so i take in 3 healthy tangs from a friend going to Iraq . . . a few days later my ozone goes down then ich appears. By the time i get the replacement bulb, orp falls from 400 to 80. Lost about 20% of fish . . . mostly yellow tangs and green chromis so not much $. I know this is anecdotal, but as soon as i got the ozone back online, the ich began to fade! Fish are out again, active and most importantly eating!

So i am a big fan of Ozone! First problem i have had in 4 years since running ozone . . . and now i have a back-up ozonator.

 

[Randy Holmes-Farley]

You sure it was ich? Most reefers do not use ozone in a way that would actually kill organisms such as ich. That is, they do not use enough for long enough contact time. How are you using it?

Maybe the effect was indirect, such as through the tank having low O2 or something else wrong when the ozone was off. Your ORP drop was quite dramatic.



I discuss it here:

Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry
http://reefkeeping.com/issues/2006-03/rhf/index.php

Ozone and the Reef Aquarium, Part 2: Equipment and Safety
http://reefkeeping.com/issues/2006-04/rhf/index.php

Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone
http://reefkeeping.com/issues/2006-05/rhf/index.php

from the first one:



http://reefkeeping.com/issues/2006-03/rhf/index.php#14


Reducing Other Pathogens When Using Ozone
There has been extensive analysis of the amount of ozone needed to kill the human pathogen Cryptosporidia parvum in freshwater. Most such studies are looking for significant disinfection, but some data points show the effects at lower doses and contact times, and some researchers have developed models that suggest the amount of killing at any dose/time combination.43 For example, at 22° C approximately 63% of the organisms would be expected to be killed at 1 ppm ozone with a contact time of one minute. The contact times and concentrations are inversely related, so at a contact time of six seconds, the required dose to kill 63% is on the order of 10 ppm ozone. At 0.3 ppm ozone and a six second contact time, typical for the high end of reef ozone applications, less than 5% of the organisms would be expected to be killed.

Many viruses are much easier to inactivate with ozone than are other pathogens.44 Enteric adenovirus, for example, is inactivated to the extent of 99.8% after exposure to 0.5 ppm for 15 seconds.44 Feline calicivirus is inactivated to the extent of 98.6% after exposure to 0.06 ppm for 15 seconds.44 Poliovirus type 1 was inactivated to 99% within 30 seconds of contact time at 0.15 ppm ozone.45 Hepatitis A virus was inactivated to the extent of 99.999% within one minute at 1 ppm ozone.46 Norwalk virus was inactivated by 99.9% in 10 seconds of contact at 0.37 ppm ozone.47 Adenovirus type 2 was inactivated by 99.99% by 0.2 ppm ozone with a contact time of about one minute.48

The eggs of a pathogenic helminth (Ascaris suum) were killed to the extent of 90% by exposure to 3.5-4.7 ppm ozone for one hour. One additional hour of exposure killed the remainder.49

It seems reasonable to conclude from such literature studies that many viruses that enter the ozone reaction chamber in a typical reef aquarium application may be killed by ozone or its byproducts. Larger pathogens, however, are likely much more resistant to ozone, and are unlikely to be killed. For such ends, a UV sterilizer may be more useful, but still may not be completely effective.

 

[quack]

thank you randy!

thank you randy!

Yes it was ich!

yes, all anecdotal, but . . . as U know, ozone works in the known and unknown. My feeling is that it reduces the exposure of nusiance pathogens, improves the quality of water and thus lessens the routine burden on the immune system of the fishies!

Just as in humans, the common cold virus rarely requires antibiotics, uunless and until secondary pathogens (bacteria) then take advantage of the weaken ed respiratory tree and invade.

and IMHO, ozone is far better than UV.

ps it took the orp 2 weeks to fall that much, and now 6 days with ozone back online, ORP is about 130. It will in my experience it will take about 10 more days to reach target!

 

[billsreef]

That's quite a drop. It suggest there are some other issues that the ozone was masking. Even a system run without ozone would not typically have such a low ORP. As Randy suggests, it's most likely a water quality related issue as opposed to a direct effect of the ozone. For ozone to be effective as an anti paracite measure, you would have to process a large quantity of tank water at high rates and long contact times, considerable more than the average hobbyist unit puts out and longer contact time than the typical skimmer or reactor provides.

 

[quack]

concur . . . like i said my anecdotal esperience. But i gotta big tank and a very bigga skimmer and can approach 720 mg/hr of ozone production if need be. Param are good.

Masking . . . whatever. In humans any treatment that keep disease at bay is called remission.

 

[snorvich]

I also use ozone. However, I do not dose by ORP reading, I simply supply a small amount of ozone constantly. I do this because I feel that livestock are healthier but I do not feel that ozone is a prophylactic or curative for ich. The only thing I notice is water that is incredibly clear; however this may or may not be attributable to ozone usage.

 

[cybrsufr]

While I fully understand the chemistry and biology Randy has spoke of many times regarding Ozone concentrations and Reef Aquaria pathogens, I too have noticed that same type on anecdotal evidence that it does work in some peoples systems. I run a Lifereef VS3 72" skimmer in Recirc and Co-Current setup using 2 Mazzie Venturi's, feed by a Blueline 70 on the Co-Current and a Mag 18 on the Recirc, so there is a lot of dwell time in the reaction chamber. The venturis are feed from a 200mg/hr Sander O3 unit connected to a controller set at 380 for low point and 420 high point. My Orp runs about 390 for most of the time. I had a pretty good outbreak of Ich after introducing a non-quarantined Powder Blue Tang to the system. Within 5 days all of my tangs were covered. I setup the O3 unit at that time and within a week the Ich was completely gone and has not returned in 4 months on any of my 30+ fish. So whether it was coincidence or not I will never know, but I really feel that it made a huge difference in its eradication from that outbreak. JMO