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Randy Holmes-Farley
03/01/2006, 07:39 AM
An article in the NY Times yesterday reported on an EPA study that is to come out in April. It shows that even low levels of ozone contribute to premature mortality.

IMO, anyone that can smell ozone in their setup, and especially in rooms of their house, should be warned about is toxicity. The health risks are sufficiently high that some folks may decide to not use it for that reason alone.

I have some articles coming up in the next few Reefkeeping Magazines on ozone, and this section from the first one highlights some of the health issues with ozone.

Ozone's Effects in the Lower Atmosphere


0.003 to 0.010 ppm
Lowest levels detected by the average person (by odor).

0.08 ppm Latest EPA study (to publish April 2006) reports significantly increased risk of premature death in humans. Each 0.01 ppm increase results in a 0.3 percent increase in early mortality.

0.001 to 0.125 ppm
The natural ozone concentration in air.

0.1 ppm
The typical maximum allowable continuous ozone concentration in industrial work areas and public and private spaces.

0.15 to 0.51 ppm
The typical peak concentration in American cities.

0.2 ppm
Prolonged exposure of humans under typical work conditions produced no apparent effects.

0.3 ppm
The threshold level for nasal and throat irritation. Some species of plant life show damage.

0.5 ppm
The level at which Los Angeles, California, declares its Smog Alert No. 1.; can cause nausea and headaches.

1 to 2 ppm
The level at which Los Angeles, California, declares its Smog Alerts No. 2 (1.00 ppm) and No. 3 (1.50 ppm). Symptoms: headache, pain in the chest and dryness of the respiratory tract.

1.4 to 5.6 ppm
Causes severe damage to plants.

5 to 25 ppm
Lethal to animals in several hours.

25+ ppm
Likely lethal to humans in one hour.

DrBDC
03/01/2006, 09:04 AM
Here are some other articals on the harmful effects and mostly bad information for owners of ozone generating air purifiers:


http://www.epa.gov/iaq/pubs/ozonegen.html

http://www.epa.gov/iaq/pubs/airclean.html

http://www.epa.gov/ozonedesignations/faq.htm

This one has a little info about marine ecosystems

http://www.epa.gov/ozone/science/effects.html

boxfishpooalot
03/01/2006, 09:27 AM
what does ozone smell like? Similar to bleach?

Randy Holmes-Farley
03/01/2006, 09:28 AM
Ozone has a sweetish smell. Not quite like bleach. Not that harsh. More pleasant.

Reefugee
03/01/2006, 09:33 AM
If you have ever been close to an old laser printer or a copy machine - they give off a very distinct smell. That's the smell of ozone.

Billybeau1
03/01/2006, 09:42 AM
I'm wondering if they make a device similar to a carbon monoxide detector that would detect O3 around a tank or in a room.

Billybeau1
03/01/2006, 10:06 AM
Nevermind, I got the answer in a duplicate thread.

Randy, Step away from the coffee. :D

Randy Holmes-Farley
03/01/2006, 10:53 AM
:lol:

It seemed important. :)

DrBDC
03/01/2006, 11:39 AM
The .003-.010 ppm that is the level to just notice it by smell is a pretty good tester. If I remember correctly they used to want the air purifiers set at .005. That would give a just noticable smell on the first sniff and not be able to notice on the second sniff. So in short, if you smell it, find the leak.

For a one time identification training, just lightly smell the the output tube but do not "huff" it. :lol: You'll know the smell after that.

thrlride
03/01/2006, 11:43 AM
If inserting ozone to the skimmer is it safe to assume that the ozone will become airborne and possibly cause these health effects?

If so, how do you prevent that from happening?

Randy Holmes-Farley
03/01/2006, 11:47 AM
If I send ozone into my skimmer, the whole basement smells of ozone.

To eliminate it, you need to pass the air/ozone through a bunch of GAC before it gets out. That isn't easy to do without hampering skimmer operation.

thrlride
03/01/2006, 12:04 PM
So basically ensure all outlets of the skimmer go through carbon?

Randy Holmes-Farley
03/01/2006, 12:11 PM
Yes. Putting any backpressure on the skimmer air flow may not be desirable, however.

jay24k
03/01/2006, 01:45 PM
If you are running only a 50 mg/h unit at half capacity, what would the risks be? Currently it is in my living room with the back facing a wall and a vent above it. The room has good circulation and is about 16'x18' I just ordered mine so I'm just checking.

I have an ASM skimmer so couldn't I just port the return water into a filter sock with carbon?

Randy Holmes-Farley
03/01/2006, 02:05 PM
Depends on the turnover of the room, how much is released, the half life of the ozone in the air, etc.

A room that is 16' x 18' x 8' holds about 2304 cubic feet, or 65,000 L. That contains about 81,000 grams of air (surprisingly large!).

So 25 mg is 25 mg/81,000 g = 0.3 ppm

I have an ASM skimmer so couldn't I just port the return water into a filter sock with carbon?

You need to pass the air over GAC too.

Randy Holmes-Farley
03/01/2006, 02:38 PM
This other thread also has some useful discussion:

http://reefcentral.com/forums/showthread.php?s=&threadid=789282&perpage=25&pagenumber=1

thrlride
03/01/2006, 03:14 PM
how did you do that math Randy? I'm curious because the room my tank is in is roughly 40' x 14' (the entire length of the house consists of the family room, breakfast and kitchen. Nearby is the two story living room wide open to the upstairs.

My generator is a 200 mg/hr unit on a controller so 'shouldn't' be on 24x7.

How would you pass the air over GAC as well?

Randy Holmes-Farley
03/01/2006, 03:56 PM
In my current ozone application, I have the air from an ozone reactor coming out of a thin plastic tubing that is stuck down a few inches into a vertical 4" PVC pipe packed with a foot of GAC. The water drains down into the tank, and the gas comes out the top or bottom. The water from the reactor also goes into this column of GAC, and out the bottom.

The only tricky part of the calculation above that isn't just a volume (l x w x h thing) is that 22.4 Liters (1 mole) of air weighs about 28 grams (that assumes it is all N2, the actual value is a tad higher due to heavier O2 in the air). :)

jay24k
03/01/2006, 04:07 PM
Well I my room feeds into multiple rooms as well and my room is actually longer and cathedral ceilings. I'm not sure on turn over as the air is running due to the warm days and always have a fan on. I'll check the other thread.

If I may, what is GAC and do you have any pictures of how you have yours setup? I plan on using a luft pump and a t valve to have it get sucked into the intake air valve of my ASM skimmer.

What would you recommend on doing as I ordered everything this morning.

Randy Holmes-Farley
03/01/2006, 04:48 PM
GAC is granular activated carbon. I use Marineland Black Diamond. No pictures yet. :)

jay24k
03/01/2006, 05:03 PM
I apologize if I'm asking too much or just not getting it.

You have your outake of your ozone into a tube of GAC before it hits your skimmer? Does having it go into GAC before it hits my skimmer make it any less affective?

I could easily have all my water from my skimmer go into a filtersock with carbon but not sure on how to do the air portion unless it passes through carbon first but I'm not sure if that would affect the oxygen content.

justinzimm
03/01/2006, 08:16 PM
Randy,

Thanks for the great info. I've got a question about the ozone levels you posted. I smell ozone sometimes at work so I know the smell and can notice it before allot of my friends. I've never noticed it outside work or even when I visited LA during heavy smog days. If I can smell O3 at .001 to .010 ppm why havent I noticed it in nature or even smoggy cities? Also, are these exposures over time or a one time dose?

Thanks,
Justin

Randy Holmes-Farley
03/02/2006, 06:56 AM
You have your outake of your ozone into a tube of GAC before it hits your skimmer? Does having it go into GAC before it hits my skimmer make it any less affective?

GAC breaks down the ozone and certain ozone byproducts. So you want the GAC in the air and water after it leaves the skimmer. I agree that it is hard with the air, and also it is hard to get adequate contact time with the water since the flow rates are often very high. :)

Randy Holmes-Farley
03/02/2006, 06:59 AM
I've never noticed it outside work or even when I visited LA during heavy smog days.

I never recall smelling it on smoggy days either, although at the time I lived there I did not know what it smelled like. One thing is that your nose can become accustomed to it. So asking if a person can smell 0.1 ppm when comparing it side by side to 0.00 ppm may be very different than asking if someone living in 0.1 ppm smells anything.

Also, are these exposures over time or a one time dose?

OSHA permitted levels for most chemicals have various time constraints, such as time weight over 8 hours, as well as instantaneous maxima.

DrBDC
03/02/2006, 11:08 AM
Here is an interesting page. There are a lot of claims for ozone benefit but the one I find interesting is the one about breathing it after bubbling through olive oil. Different I must say.

http://www.geocities.com/ojoronen/OZ.HTM#100

Randy Holmes-Farley
03/02/2006, 11:30 AM
good heavens, check this one:

DIRECT IV INJECTION OF OZONE

"Some patients will cough after injection as the ozone outgasses in the lungs. "

DrBDC
03/02/2006, 12:37 PM
And the cavity injection. The ozone production produces heat, so would it be blowing a lot of hot air up your ###?

Bubbob
03/03/2006, 03:06 AM
Randy
Have you ever had a fire in your dry filter?
I've had two so I gave up on them.

Randy Holmes-Farley
03/03/2006, 06:29 AM
You mean the carbon caught on fire? Wow. How much ozone were you using?

Bubbob
03/03/2006, 02:20 PM
I run it at 125 mg/h.
The unit only tends to run in short bursts.
It mayu have alot to do with the filter size as the ones that I made were small.
How much carbon does your hold.

Randy Holmes-Farley
03/03/2006, 03:27 PM
It holds between 1/2 and 1/4 gallon of GAC, I expect.

Bubbob
03/03/2006, 03:39 PM
Mine were alot smaller.
The size of the carbon may have also be an issue, mine was very fine.

Randy Holmes-Farley
03/03/2006, 03:54 PM
Oh, OK. Mine is the usual Marineland Black Diamond pellets. :)

Thanks for the warning. I would not have worried about a fire.

Bubbob
03/03/2006, 07:24 PM
Hhmm If I had the time I'd become a fire bug and do some experiments, I would see how hot diferrant chamber sizes and carbon size get.

thrlride
03/06/2006, 05:57 PM
Randy, what are the pros and cons of using a ozone reactor instead of sending directly in to the skimmer?

Randy Holmes-Farley
03/07/2006, 06:00 AM
Ozone reactors may have longer contact time, may be under more pressure (forcing the O3 into the water), and may allow the air and water to be passed over GAC more readily than many skimmers.

My tubing coil also allows these things, although it may not mix as well as a really good reactor.

thrlride
03/07/2006, 08:39 AM
I can only find the coralife reactor, is there a really good one?

jknecht
03/07/2006, 09:54 AM
What do you think about the new OxygenFresh Fans that Sharper Image sells? They are suppose to convert ozone to oxygen. Do you think they would help if you have a slight smell of ozone in the air? I have a 16 x 17 fish room setup in my basement running a Sander 50mg/hr at about 20%. I run it into a Coralife Ozone Reactor then into a Phosban Reactor filled with Carbon and can still smell ozone if I put my nose to the sump. I can also smell it in the air when I walk down to the basement. It's ever so slight but still present.

Randy Holmes-Farley
03/07/2006, 09:54 AM
I can only find the coralife reactor, is there a really good one?

The Coralife reactor should be avoided. I used it for 2 weeks, and will not again.

Yes, there are good ones, although they are expensive:

http://www.marinetechnical.com/page6.html

Randy Holmes-Farley
03/07/2006, 09:59 AM
What do you think about the new OxygenFresh Fans that Sharper Image sells? They are suppose to convert ozone to oxygen.

I do not know how effective that is at ozone removal.

It is a different application entirely, but here the EPA criticizes air cleaners that generate ozone:

http://www.epa.gov/iaq/pubs/ozonegen.html

jknecht
03/07/2006, 11:01 AM
Randy what types of problems did you run into with the Coralife Reactor? I just hooked mine up last week and am a little concerned.

Randy Holmes-Farley
03/07/2006, 11:23 AM
The internal hard plastic tubes seemed to very rapidly no longer fit and hold into the slots in the drip plates, it is very hard to get it put together with the bioballs inside without the tubes falling out, the air vent hose (that also takes out some water) seemed too loosely connected, and bumping it made it fall off repeatedly, the airstone started making only large bubbles after about 2 weeks, it takes way too long to open and close it.

The bulk water did not get very highly ozonated, maybe due to the large bubbles.

I guess that's al I remember right now. :)

jknecht
03/07/2006, 12:12 PM
I agree it's poorly designed... I'll have to keep my eye on it to make sure it doesn't eventually fall apart. I'll have to look into getting one from marinetechnical. Thanks for the info and the link.

Randy Holmes-Farley
03/07/2006, 01:33 PM
You're welcome.

Good luck. :)

DrBDC
03/07/2006, 01:35 PM
That one looks pretty easy to diy. The plastic looks like typical plastic shavings as if you took a plane to a piece of pvc. It seems like a place to get detrius clogged though.

kmagyar
03/07/2006, 03:40 PM
Yes, That looks way to simple. I myself am interested in making one. Randy, How should the ozone be intruduced? Could I used bio balls? That unit has a pressure gauge as does their calcium reactors. Is there any need for that?

Keith

jdieck
03/07/2006, 04:06 PM
Here is the setup I use to manage the air vented from my skimmer.
The collection cup has a drain that is hosed to a waste collector, the collector has activated carbon chamber in the exaust and the exaust is piped to the outside of the house.
The skimmer is a down draft ETS 1000 running on an Iwaki RLT70 which generates a pretty good air pressure so the housing has not been a problem. I noticed that slightly pressurizing this kind of skimmer increases the speed of disolution of ozone, reduces the bubble size, increase the amount of foam and increases the staility of the foam column.
http://jdieck1.home.comcast.net/Waste_Collector.jpg

Bubbob
03/07/2006, 06:19 PM
Hang on a minute PVC and bio-balls are not stable plastics when in contact with Ozone and may cause toxins to be released from the plastics.
You guys need to be more carefull about this issue and more aware of what materials are in your skimmers and reactors at any point of contact with the O3.
I haven't used a comercial reactor before and most likely wont as there pretty simple to build, so I can't comment on the materials they use because I do not have one to look at.
I have a gas compatability chart somewhere about this from a manufacturer I'll see if I can find it.

jdieck
03/07/2006, 07:06 PM
Tested at more than 1000 ppm of Ozone
PVC = Good
CPVC = Excellent
Low Density Polyethylene = Good
High Density Polyethylene = Excellent
Polycarbonate = Excellent
Polyacrylate = Good
Silicone = Excellent
Polypropylene = Fair Used in small fittings
Nylon = Severe Effect Used in many small fittings
Buna N (Nitrile) = Severe Effect (Normally used in O Rings for Skimmers) recomend to switch to silicone O rings

So in summary the risky areas for a Skimmer are some small fittings, same fitting may come in different materials Nylon, Polyethylene or Polypropylene so check your compatibility. Also O rings may have to be replaced. For Silicon O rings go to www.mcmaster.com most sizes available. You can also use Teflon O rings but they are more expensive and less flexible so may not seal as well as silicone.

http://www.ozoneapplications.com/info/ozone_compatible_materials.htm

Bubbob
03/07/2006, 08:05 PM
The problem is that most studies are only based on effect of Ozone with the material, not what they will start to release due to the reaction.
PVC is a good example and depends on its form and density as to how good it is.
The only ones you should pay attention to are the ones that say nil or none
I don't like there chart, the one I have,(when I find it) says something like none, some and alot. It is more spacific in it terms so I'll keep looking for it.

Randy Holmes-Farley
03/08/2006, 07:05 AM
Randy, How should the ozone be intruduced? Could I used bio balls? That unit has a pressure gauge as does their calcium reactors. Is there any need for that?

The basic goals, as I understand them, are to have as much air/water contact area and time as possible, have a long time where the ozonated water can "react" before it passes over GAC, and have the whole air/water mixing area under some pressure if possible. All of those things will maximize the ability of the ozone to get to and react with chemicals in the tank water.

My April Reefkeeping article will primarily cover these topics. :)

ReefAddict1
03/14/2006, 01:46 PM
interesting