Ozone generator on skimmer

[lrhorer]

I have purchased an Enaly O3 generator and a CO2 scrubber I would like to add to my Eshopps PSK-100H protein skimmer. I know from reading O3 should never be introduced directly into the tank, so it needs to be consumed before adding the treated water back. I read some suggestions about using an activated carbon filter into the return path. This might be challenging with the Eshopps filter. I am wondering how necessary it is to do so. The aerated water travels through a highly turbulent path nearly 1 meter long before being introduced back into the aquarium through a foam filter. Would this be sufficient to reduce the O3 levels in the stream to safe levels for re-introduction into the tank?

If not, I have considered re-plumbing the skimmer to flow into the sump intake. Would this be problematical for the bio-filter media in the sump? I could also plumb it directly into the sump, bypassing the bio-filter.

Am I worrying about nothing?

 

[slief]

In my opinion it is very important. Ozone will be staturating the water in the skimmers effluent. Not only that but it will escape through the skimmer lids vent holes. You should have carbon covering the skimmer lid vents and the route 100% of the skimmers effluent through carbon. Ozone in the air will damage any non ozone safe plastics around your tank and make them brittle and crack. It is dangerous as well to both people, pet and fish. Personally, I am not a fan of using a skimmer for ozone. With a skimmer, you have no control over the ozones contact time and then you have the issues in dealing with the excess ozone.

If you are going to play with ozone, an ozone reactor is a much better solution for a number of reasons. First, you can control the water flow rate through the reactor to adjust the contact time for best results. A properly tuned ozone reactor will have a much higher ORP effluent than a skimmer which will result in better efficiency when it comes to the use of ozone and better water quality within the tank. The other reason why a reactor is a MUCH better solution is because you can eliminate excess ozone by routing the ozone reactors effluent through a carbon reactor filled with the appropriate carbon. I like to use lignite carbon for ozone. Lastly, because the reactor is sealed, you don't need to worry about ozone escaping through the vent holes like you do in the case of the skimmer.

That said, having used ozone for many years, you should really think about your use of ozone and consider other option. For example, a properly sized and setup quality UV sterilzer can have very similar results to ozone. They both oxidize organics and both can have a very significant impact on ORP and water quality. A UV sterilzer doesn't present the issues that ozone does. It's safe for the surrounding equipment, doesn't emit dangerous gas, is easy to setup, eliminates bacterial blooms, reduces parasites, reduces water born algae etc.

I've run UV for decades and no longer use my ozone. Without my UV Sterilzer, my ORP is around 275-300. With it on, my ORP is typically in the 400 range.

This screen shot was taken several days after replacing the bulbs in my AquaUV 114 watt sterilzer. I normally replace my bulbs every year but went too long and they died causing my ORP to drop dramatically. This shows the ORP's quick rise after replacing the bulbs.

My typical ORP now.. This is despite over 70 fish in my reef with ridiculously heavy feeding and no ozone. The ORP on my Profilux also matches that of my Apex ORP probe.

 

[lrhorer]

In my opinion it is very important. Ozone will be staturating the water in the skimmers effluent.

I would not expect the water to be saturated with a fairly low O3 flux.

Not only that but it will escape through the skimmer lids vent holes.

That depends on how saturated the water is with O3, but your point is taken.

You should have carbon covering the skimmer lid vents

That is easy enough.

and the route 100% of the skimmers effluent through carbon.

That was my thought. The output of the skimmer is ordinary 1/2" PVC. I could fairly easily re-plumb the output towards the sump instead of the tank and insert a carbon filter.

Ozone in the air will damage any non ozone safe plastics around your tank and make them brittle and crack.

Yes, as well as various rubber products and other organic materials.

It is dangerous as well to both people

Not at fairly low concentrations or in a well ventilated room. Indeed, many air purifiers vent small amounts of O3 directly into the air. You are correct, however, that one must take some care when dealing with O3 indoors, as its half life in air is much longer than in water, especially in water with a high pH.

Personally, I am not a fan of using a skimmer for ozone. With a skimmer, you have no control over the ozones contact time and then you have the issues in dealing with the excess ozone.

That depends on the setup. First of all, dealing with the amount of excess O3 should be a matter of reducing the rate of production coupled with venting the skimmer through a carbon filter or outside, or both. Secondly, I submit the contact time itself is not significant within reasonable limits because the half life of O3, even in high pH water, is still on the order of 10 minutes.

If you are going to play with ozone, an ozone reactor is a much better solution for a number of reasons.

They are also quite expensive, which is a matter for concern.

First, you can control the water flow rate through the reactor to adjust the contact time for best results. A properly tuned ozone reactor will have a much higher ORP effluent than a skimmer which will result in better efficiency when it comes to the use of ozone and better water quality within the tank.

Thanks. Good points.

The other reason why a reactor is a MUCH better solution is because you can eliminate excess ozone by routing the ozone reactors effluent through a carbon reactor filled with the appropriate carbon.

Well, that is easy enough to do with my skimmer, as well. As I mentioned earlier, its output is 1/2" PVC pipe, and since it is a meter above the sump water level, it would be pretty easy to install a carbon filter. Indeed, if I route the effluent into the sump input, it will automatically pass through a carbon filter bed, but I am concerned the effluent might tend to kill the bacteria in the biofilter, even though the carbon filter precedes it.

I like to use lignite carbon for ozone.

Why, specifically, rather than activated charcoal, and what is your source for the product?

Lastly, because the reactor is sealed, you don't need to worry about ozone escaping through the vent holes like you do in the case of the skimmer.

As I say, that's pretty easily addressed.

That said, having used ozone for many years, you should really think about your use of ozone and consider other option. For example, a properly sized and setup quality UV sterilzer can have very similar results to ozone.

I tried one a few years ago, and did not have good results. First of all, I saw very little impact on the tank over all as compared with the same system without the UV sterilizer. Secondly, the UV bulbs were rather expensive and hardly lasted any time at all. Not only was it rather costly, it was a pain to maintain.

All that said, your input is most appreciated and very well taken. I will consider carefully before implementing any system - other than the CO2 scrubber, that is. I don't think there is any argument against reducing the CO2 level in the tank using a soda lime reactor, provided I take steps to insure the reagent remains dry.

 

[slief]

Rather then go through each point, I will try to simplify things.

I've used ozone on and off for over 25 years. I've also done some basic testing using ORP as my guideline. Contact time is VERY relevant regardless of half life. The ORP of the effluent from a skimmer injected with ozone is typically far less than that of an ozone reactor and you need a much high mg/hr of ozone for results that are even close to using a reactor that is tuned well. Most skimmers flow 300 GPH + unless it's a really small skimmer. In your case, the pump on a PSK-100 flows around 357GPH. That is kind of high for ozone when you consider the size display that skimmer is rated for. To maintain a higher ORP in a skimmer, you need to run the ozone at a higher concentration. To maintain higher ORP in the system, you need MUCH greater ozone concentration with the skimmer. By slowing the flow rate down through the reactor, you can use less ozone to obtain higher ORP with less residual o3 in the water. I've tested the ORP results from ozone using both methods and the reactor is MUCH more effective not only on the effluent but also the tank. You also don't smell the residual o3 in the air when using a properly setup reactor but you usually will with a skimmer. If you can smell it, it is not good!

Regarding using charcoal. HLLE has long been attributed to the use of carbon and in particular the dust associated with carbon. Some carbon produces more dust than others. Also, the more flow you put through carbon, the more it tends to break down. Running 300 gph through the amount of carbon you will need to strip the residual o3 from the water will likely cause the carbon to break down and release carbon dust. This brings up to things.. One, slower flow through carbon not only makes more effective use of the carbons ability to remove the o3 but it's also safer for the tanks inhabitants. This is not only another reason for using an ozone reactor but also a reason why choosing a quality carbon is important. Lignite is inexpensive, relatively hard so it won't break down easily and it has very good absorption properties. When I use ozone, I get my lignite in bulk from Bulk Reef Supply.
http://www.bulkreefsupply.com/brs-bulk-small-particle-lignite-aquarium-carbon.html

Lastly, you mentioned poor bulb life and poor results from UV. I would have to question the model UV you were using as well as how you had it setup. A quality UV such as those from AquaUV has bulbs that last much longer than a cheap one. Most other UV's need their bulbs changed every 6 months. AquaUV's last well over a year but should be chanced once a year for maximum effectiveness. I will also note that sizing the UV and the flow rates are critical to their effectiveness. A UV that is too small will not have much if any impact. Too much flow through the UV will also have little impact on overall water quality. Those graphs above show how effective UV can be. Those are on my 700 gallon system with a 114 watt AquaUV. I run around 1300 GPH through it. That was the impact after replacing bulbs that were 1.5 years old. You mentioned that the UV was a pain to maintain but there is next to no maintenance with a quality UV. Replace the bulbs once a year and clean the sleeves once a year. That or get one with a wiper like mine. Then move the wiper back and forth every couple weeks. There is in fact more maintance with ozone. You have carbon that should be replaced every moths or two. You have to run a drier for best use of ozone or risk damaging the generator. If you use beads, those need to be rechanged. If you use an electronic drier, that are very costly.

 

[slief]

Don't get me wrong. Lots of peope run o3 on skimmers but most have no idea how inefficient that method is and much more effective a properly setup ozone reactor is. My experience with ozone over the years has led me to feel skimmers don't make very effective use of ozone and the impact on water quality is minimal without running a very high mg/hr of ozone. An ozone reactor on the other hand can do a much better job improving water quality while allow the user much more control over the use of ozone with less environmental impact on the equipment and inhabitants in and around the system.

 

[Marc]

Slief

Scott can you tell me if Ozone has a direct impact on algae growth in the tank? Does ozone keep algae such as diatoms under control? How about green algae and red slime?

Thanks,
Marc

 

[slief]

Slief

Scott can you tell me if Ozone has a direct impact on algae growth in the tank? Does ozone keep algae such as diatoms under control? How about green algae and red slime?

Thanks,
Marc

The only impact ozone would have on any algae is waterborne algae and in my experience, the impact is minimal. Same with diatom. A properly setup UV sterilzer would work better for both in my opinion but again, when it comes to algae, the impact will be minimal.

 

[reefkeeper2]

I've used ozone for many years now and I can offer a few tips. First, you don't need a lot of ozone to get the real benefits of it's use. It's a good example of when less = more. I don't use an air dryer and I only run it 8 hours a day in my system of approximately 500 gallons. This is enough for crystal clear water and improved organic removal in my skimmer. My ozonizer is undersized for my system so even if it were on 24 hours a day, it could not overdose the tank. My apex monitors the ORP just in case, but it has never turned it off. I really don't care what the ORP value is and I don't even look at it.
Carbon is used for two reasons. First is to remove excess free ozone, and second to remove the toxic by-products of ozone's reactions with sea water. I don't know exactly what they are, but Randy Holmes-Farley has an article where he lists them. There has always been debate on if it is necessary to use carbon with ozone. Some people don't, especially if they have a large system where free ozone is not likely to make it back to the display. I do use it as I'm a cautious reefer. I use carbon pads, not granular carbon on the outflow from my skimmer. Much easier. My skimmer is vented to the outside so I don't have to worry about ozone getting into the house. It was easy to do with a large funnel and some tubing.
All this being said I have to say I like ozone because I can see the tank does better when I use it. Most noticeable for me is absolutely clear water and better polyp extension on my sps.

 

[lrhorer]

I've used ozone on and off for over 25 years. I've also done some basic testing using ORP as my guideline. Contact time is VERY relevant regardless of half life.

That was my point, actually. If the contact time were on the same order as about 8 times the half life (call it 20-30 minutes), then longer contact times would have little additional impact. As it is, essentially any dissolved O3 is going to remain dissolved in the fluid throughout its journey through the device, regardless of the time of contact. Of more importance, and in this case less quantifiable without empirical measurements is the saturation of O3 in solution. Contact time is certainly an important variable WRT saturation, up to the point where the solution approaches 100% saturation. It is this which determines the impact on ORP. How ORP relates to the biological activity of the setup is not going to be a simple matter, nor is a measure of ORP necessarily functionally related to the effectiveness of sterilization across various setups. All that said, there is no question for a given setup both the ORP and the sterilization effectiveness will generally increase with a greater contact time, as you say.

The ORP of the effluent from a skimmer injected with ozone is typically far less than that of an ozone reactor and you need a much high mg/hr of ozone for results that are even close to using a reactor that is tuned well.

I have no doubt at all this is probably true. In a simple skimmer, there may not be enough effective surface area to produce a high level of saturation of O3 in the solution.

You also don't smell the residual o3 in the air when using a properly setup reactor but you usually will with a skimmer.

I submit that is as much an effect of the carbon post-filter as the effectiveness of the reactor, coupled with the lower O3 concentrations employed with the reactor, more than the O3 efficiency of the reactor. I don't have any data on-hand, but I suspect less than half of the O3 is actually consumed in the reaction chamber. I suspect efficiencies that high would require a much larger reaction chamber with much smaller bubbles and much greater agitation. Even then, the efficiency may not approach 50%, depending on the solubility of O3 in the fluid.

If you can smell it, it is not good!

That is a bit of an over-statement as well as an over-generalization. Certainly continuous exposure to O3 levels high enough to be sensed by the human nose can cause various health risks, and as previously mentioned continuous exposure to various hydrocarbons can result in deleterious chemical reactions within the body of any artifice substantially composed of those compounds. Indeed, due to modest levels of O3 produced by various electrical devices in the physics lab where I used to work, rubber and certain plastic hoses never lasted very long, at all.

It is rather a different thing to make a blanket statement such as the one above. Being able to catch a whiff of O3 near a generator setup does not necessarily mean the setup is maintaining unhealthful levels of O3 in the room as a whole. I submit if it cannot be smelled more than 1/2 meter or so from the output and the room is reasonably well ventilated, then there is little cause for concern. If one can smell O3 whenever one walks into the room, it's a different matter.

Regarding using charcoal. HLLE has long been attributed to the use of carbon and in particular the dust associated with carbon.

I was unaware of this. Thank you.

When I use ozone, I get my lignite in bulk from Bulk Reef Supply.
http://www.bulkreefsupply.com/brs-bulk-small-particle-lignite-aquarium-carbon.html

Thanks, again.

Lastly, you mentioned poor bulb life and poor results from UV. I would have to question the model UV you were using

So did I. That's why I quit using it. I don't recall the make or model: that was 30 years ago.

as well as how you had it setup.

Water flowed in to the input and out of the output. What more is there?

A quality UV such as those from AquaUV has bulbs that last much longer than a cheap one.

'Not an unreasonable assertion. Mine only lasted a few weeks.

A UV that is too small will not have much if any impact.

It was sized to the tank (30 gallons, at the time).

Too much flow through the UV will also have little impact on overall water quality.

It had a pump included. I never measured the water flow.

Those graphs above show how effective UV can be. Those are on my 700 gallon system with a 114 watt AquaUV.

Scale may be a factor, here. Mine is currently only 100 gal.

You mentioned that the UV was a pain to maintain but there is next to no maintenance with a quality UV.

Replacing the bulbs was not all that easy, nor was it particularly cheap.

You have carbon that should be replaced every moths or two.

I was going to ask that. How does one know when / how often the carbon needs to be changed?

You have to run a drier for best use of ozone or risk damaging the generator. If you use beads, those need to be rechanged.

Did you mean, "recharged"? I have not received the O3 generator, yet, so I do not know what the drier media is. Is it by chance silica gel? Silica gel is easy to re-desiccate. That, and I can get it inexpensively from my local dive shop or online.