Sharing a Perspective - re Ozone, skimmer op.  05/04/06
Hi Eric,
<<Hello Andy>>
I read your reply to Ross, about ozone use, on 2nd May.  I had a similar sized tank, was running ozone and upgraded from the Deltec MCE600 to the APF600, and feel I may be able to add to the good advice you offered Ross.
<<Ahh, excellent!>>
I hope you don't mind.
<<Not at all...will post for all to see/share...and hope you don't mind in kind if I throw in a comment where I get the urge...>>
The use of Ozone is highly beneficial, but often delivered at too high a rate.  When ozone is first introduced to a tank it may take a few days or weeks to break down the waste products that have accumulated in the tank environment.
<<Mmm, in their entirety maybe (though new "waste" is being generated all the time), but ozone is highly reactive/its effect is immediate...as I'm sure you are aware>>
However, once that initial spring clean is complete the rate of ozone should be reduced - especially if the owner has a strong maintenance schedule (water changes, not over stocked, not over-feeding, etc, etc).  The lack of skimmate (and nitrate) is an indicator that the ozone is being over-applied (organics being burned up long before they can get to the skimmer cup).  I would recommend reducing the ozone rate to 10mg/h, allowing the water to get a slight yellow colour once again (best to assess this at water change time); at each water change assess the tank water colour - if yellow: increase the ozone rate by 5mg/h, if blue: (associated with a tank aerated with ozone) you have reached a nice compromise between getting the benefits of the ozone, while minimizing the unwanted effects (smell and risk of overdose).
<<With most units available to hobbyists here in the states, overdose is of small concern on all but the smallest of tanks>>
I suspect Ross may only need to deliver ozone at half the current rate.
<<Is a possibility...though I don't consider 40-50 mg/h to be "excessive" on a 180 gallon tank...>>
In terms of the MCE600 to APF600 upgrade, it is an improvement but only a small one.  I got perhaps a 20% increase in skimmate from one to the other.  For me, the major benefits included a much bigger collect cup, and hiding away the skimmer with a sump (the hang-on MCE couldn't fit in the gap above the sump, but the APF just sat outside the sump cupboard).  From a chemistry perspective, the amount of ozone being generated by these units cannot accumulate in an average home room.
<<Agreed...and my point/surprise at Ross's comment re>>
Ozone is so reactive that it will always quickly (seconds) find something to react with, preventing build-up.  The smell is actually a by-product of the ozone reaction with various materials.  Reducing the amount of ozone to the minimum necessary to achieve the desire results will minimize the smell - but not remove it completely.  The headaches Ross is suffering could be the irritation of the ozone by-product (not in itself harmful, just unpleasant).  I tried to reduce this smell by placing carbon on the air vents of the skimmer, but found it stopped removing the smell after a few days due to humidity saturating the carbon surface.
<<Indeed, many folks don't realize how quickly carbon can/will become "saturated" with impurities...can be from minutes to days depending on quality...the same holding true for the carbon used for our water/tank filtration>>
I never could find a satisfactory way to add carbon to these skimmers.
<<A few manufacturers have tried to incorporate "chambers" for such...but most, including these so called "top of the line" skimmers (Deltec, Euro Reef, etc.) don't bother.  But I haven't really found a need for it either...in my experience>>
There are a few skimmers on the market with large carbon cups that sit on top of the skimmer cup - these may reduce the smell for longer, but many are not top rated skimmers.
<<Mmm...guess I should be reading ahead <grin> >>
One solution would be continuing to use the MCE600 as his primary skimmer (it has a fabulous performance for its size), and install a new skimmer, with a built-in carbon cup, as a dedicated ozone delivery device.  Best of both worlds, and I suspect the carbon cup skimmer may be cheaper than the APF600.
<<The ones I've seen are!>>
That said, even with a large carbon cup, my own experience says, the carbon surface will become saturated from the humidity, and the ozone by-product smell will return.
<<I wouldn't think the moisture alone in the air (humidity) would have a "saturation" effect on the carbon, else placing it in our tanks would render it useless immediately...but I do agree the impurities in the air exiting the skimmer would have a very rapid effect>>
There is no substitute for minimizing ozone delivery to the minimum necessary to achieve your results.  I hope this helps.  I wrestled with the same issues for months, tried everything my LFS and I could think of, and ultimately couldn't find a perfect answer.
<<Is there such a thing? <G> >>
Eventually I was seduced by the "natural side" (rather than the dark side) replacing pretty much all the technology (except the skimmer) with a natural system (refugium the same size as the display, deep sand bed, micro algae, lots of live rock and Tunze stream circulation on the display) - the result was a level of filtration, stability and simplicity that technology (ozone included) could not provide.
<<Am much in agreement with this/your approach and use something very similar myself...but still I believe most any system can benefit from the application of ozone>>
It is ironic that I wasted thousands of pounds on technology, before coming to realize that nature already provides the best available solution (and for half the ultimate cost)!
All the best,
Andy
<<Andy, thank you for sharing.  Kind regards, Eric Russell>>

Change in Skimmate from Ozone Use - 04/28/06
Hi guys! <<and gals!>> Hope all is well!
<<Yes, thank you>>
I emailed a while back when I was moving from a 50 gal tank to a 180, glad to say it all went far better than expected (besides my Powder Blue stressing himself out and getting a tiny amount of white spot... I was expecting that and it cleared up by itself, close on to a year I've had him now).
<<Mmm, difficult specie to keep long term...I wish you continued good luck>>
Anyhow, enough of my ramblings and to the point!  I recently added a Sanders 100 ozonizer.
<<Good product>>
At the moment it's putting around 25mg/h of ozone into my skimmer (Deltec MCE600 - which seems to be handling the large tank quite well, although I'm considering an upgrade if I get more stock in the future).
<<Indeed>>
I run the overflow of the skimmer into a gallon glass container, otherwise I'm emptying it twice a day (or I was, until I added the
ozone).  Therein lies the question... since adding the ozone I was
expecting a small decrease in the concentration of skimmate (slightly less dark) but in the same quantities.  I hardly get any skimmate during the day now, but overnight I seem to get a lot, though nowhere near as much as I used to.  The only other change to the tank has been the addition of four assorted soft corals over a period of a couple of months.
<<Should not have an affect on what you are seeing here>>
My skimmer's clean and running as well as it ever has, is this simply down to some of the organics the skimmer would normally remove being oxidized?
<<Is due to this (in part at least), yes.  Another contributor may be the addition of the ozonizer is restricting air flow to the skimmer pump...perhaps larger diameter tubing will help...or a larger skimmer>>
I wasn't expecting such a difference with such a small amount of ozone.
<<The ozone itself would likely have less "obvious" affect on a skimmer with a larger reaction chamber, but I wouldn't be concerned.  Just try to readjust the skimmer for optimum skimmate>>
Thanks again guys,
Ross Cranford
<<Happy to help, Eric Russell>>
P.S. I have a pair of maroon clownfish, the female has taken to a bubble anemone that I added just a day ago and she won't let the male near it, is that normal?
<<Yes, will likely "ease up" in a while>>
P.P.S. Is Bob's book published in the UK?  I'm after a copy but can't seem to find it!
<<Mmm, would think so...Bob?  You can also order it from Amazon.com.  EricR>> <Think it can be had via Amazon UK, yes. RMF>

Ozone use, filtering output water through carbon
Bob,
<Steven Pro in this morning.>
I am using a large Euro-Reef skimmer in my sump. I'm getting ready to install an ozonizer, but can't see any simple way to filter the outflow through carbon.
<Simple enough, just add a T to the top of the outflow, so that it is arranged with one part straight down, one part straight up, and the last part sticking out the side. To the side piece connect an elbow. Under the elbow, Jimmy-rig some sort of basket to hold carbon. In this way, excess air/bubbles are able to vent out the top of the T while the water is redirected to the carbon. The only hard part maybe finding pipe fittings to match the Euro-Reef plumbing.>
So I'm going to purchase an oxygen/ozone reactor and plumb the reactor in line with my magnum canister filter using the carbon basket. Is it necessary to do this.
<It is safest to use the carbon after ozone, if that is what you are asking.>
Seems to me that the ozone would be more effective running through the big 12 inch diameter skimmer.
<I would first double check that the Euro-Reef is ozone safe. Their webpage is here http://www.euro-reef.com/>
Then again, the ozone reactor is will be used with 4-6 PSI so perhaps I'm wrong. The magnum canister pump will be circulating the water (350 gph) nothing compared to the flow of the skimmer with its two pumps. The ozonizer I purchased is a Aquazone 200 with Redox control. Must/should the ozonized water be filtered through carbon?
<Yes, for safety sake.>
Also, I am having an outbreak of ick or velvet.
<Two very different looking diseases with somewhat different treatments. Cryptocaryon looks like grains of salt attached to the body of the fish. Amyloodinium looks like a film on the body, not as easily seen and kills much faster than Cryptocaryon. Please reference www.WetWebMedia.com for additional information.>
I'm slowly raising the temp to 85 and dropping salinity also.
<Only moderately effective against Ich/Cryptocaryon, this will do nothing against Velvet/Amyloodinium.>
Contemplating using ruby reefs reef safe medication.
<I found the Ich medication from them to be almost useless. My complete coverage of treatment options will be coming out in our new online magazine, "Conscientious Aquarist", in the second issue.>
Tank is 450 gal reef, lots of stuff in it. No way to strip it, catch, put everything. Any experience with these reef safe medications?
<Nothing that will make you happy to hear.>
I foolishly fed the tank some live brine shrimp and this seems to have started the problem.
<I would look for another root cause. There is extremely little likelihood that this was the problem.>
Any suggestions?
<Are you a religious man? Have you led a good life? Perhaps you will get lucky. Let us assume/hope that this is Cryptocaryon. I would start with the lowered salinity and increased temperature, but you are stuck with the inverts not to go too low. With corals, I would not feel comfortable going lower than 1.020. I would get that ozonizer running, ASAP. There are other alternatives; daily 50 gallon water changes, find a medicated food or make your own food with Metronidazole, add some cleaner shrimp, and use garlic.>
Thank you, Paul
<Good luck! -Steven Pro>

Protein skimmer and ozone
Hi, Merry Christmas.
<and the same to you my friend>
Just a short question.  When I started to inject ozone into my Tunze skimmer. I found that the foam was weakening and in half-hour or so, it didn't accumulate in the cup.  Is this normal?
Regards, TFChow
<patience good sir. Any disruption will cause a delay in skimmate production... 12-18 hours is no surprise. Even without the ozone, often just your hand in the tank disruption the proteins at the water surface is enough to delay skimmate. All in good time. Tunzes once tuned correctly are generally very good skimmers. Best regards, Anthony>

Free radicals (not a plea to release terrorists)
Bob,
<Andrew>
I am hoping your knowledge of chemistry can reassure me somewhat about ozone application. Some facts and figures.
<okay>
350l reef tank, 6 months old.
Biological filtration provided by 55kg of Fiji live rock combined with 30x per hr water movement. No detectable ammonia, nitrite or nitrate.
Eheim canister containing floss (changed weekly to avoid biological build-up),
<Good idea>
chemical media (RowaPhos and carbon), with the return going through a UV.
Deltec MCE600 skimmer combined with 35mg/hr of ozone. Extracts a large amount of yuck each week, leaving the water absolutely crystal clear and slightly blue.
Deltec calcium generator, with drip rate accurately controlled by peristaltic pump. Calcium 420, dKH 11.2.
Combination of metal halide and actinic lighting.
All corals, fish and inverts settled and growing nicely.
<Sounds good thus far>
The use of ozone leaves a strong distinct odour in the room. It is not a smell of burning electricity (i.e., I don't believe it is ozone), rather it is similar to the skimmate.
<Not ozone>
The room is not that well vented, so odours can and do accumulate. My understanding is that ozone will react with an oxygen molecule to give a free radical oxygen molecule (which is cancer causing with long term exposure).
<Mmm, not so much reactions with oxygen... more a "falling apart" of the ozone/O3... with the monatomic oxygen becoming/being a free radical... in turn going on (quickly in general) to react with...>
Is there any chance that the room is accumulating free-radical oxygen molecules?
<No... the amount of ozone produced by hobbyist reactors is small... and the "life" of the reaction series resultant similarly limited>
Do you agree with my assessment that the odour is likely to be a harmless bi-product of the ozone rather than ozone itself?
<Yes, well put>
Any ideas how I can reduce the odour? My LFS tells me "in the days when ozone was used extensively carbon air filters where used for this purpose" - but I don't know how I could apply a carbon air filter to the skimmer.
<You can remove most all the smell and its cause by regular (weekly or even more frequent) placement of activated carbon in the filter flow path... yes, even though the ozone is introduced in the skimmer. Otherwise, I'd look into a "room air cleaner" (there are a few technologies to consider here...) and opening the window a bit when weather permits>
On another subject, all parameters on my tank look good, healthy and stable. One exception is my slightly low pH which starts at 7.90 early morning and finishes at 8.25 by the end of the day (as determined by a good quality electrical meter).
<Not to be overly concerned here>
I know vigorous aeration would raise this, but I don't believe it would look right in the reef setting. My LFS has recommended a Kalk stirrer, timed to come on overnight. No doubt this would work, but I am reluctant due to unnecessary(?) (a) cost, (b) complexity of set-up / maintenance overhead, (c) risks of getting the dose wrong and causing damage to the reef environment. I believe I read a WWM comment saying 7.90 as a low point is not really a problem given that many ocean reefs can be lower than this. Would you recommend I leave my set-up as it is, add a Kalk stirrer, or tackle this is some other way completely?
<You are wise to be cautious here... and consider your possibilities. The diurnal fluctuation in pH is not a worry... could be best "adjusted" by the use of a continuous or reverse daylight photoperiod refugium/sump... with photosynthesis during the main/display systems "lights off" period being offset>
Finally, My reef contains a variety of reasonably peaceful fish - yellow tang, regal tang, royal Gramma, orchid Dottyback, couple of common clowns, cardinal, six-line wrasse. I would like to add a Pomacentrus alleni, as I think it is the most beautiful damsel. My research says it is semi-aggressive, one of the more peaceful damsels, but a damsel all the same. A couple of months ago I had to re-home a blue damsel as he was a naughty chap, seriously disturbing the harmony of the tank (although I had made the mistake of adding him before many of the others - I know, I know, but I've learned a lot since then!!). I understand that each fish is an individual, therefore there are no guarantees in this game, but do you believe the Alleni is likely to reasonably behave himself in my tank?
<I do think your chances are good with adding an Allen's Damsel... more than 80-90%)>
Thank you very much for your advice. I frequently lose an hour or two reading from you site. The rumour mill suggests Father Christmas may even be bringing me a copy of your book this year!
Andrew Senior
<Ahh, hope/trust you enjoy same. Cheers, Bob Fenner>

- Cleaning Ozonizer Electrode -
How often should I clean my ORP probe? Is there anything else I can use to clean it with besides what the manufacture sells (Red Sea)?? <Hmm... not sure what it is exactly that Red Sea sells... would imagine just a rinse in distilled water once a month would do.>
Thanks,
Rob
<Cheers, J -- > 

Finding and Ozonizer that lasts 8/2/04
Hi Crew, some collective help, please. I have a 180 fish-only which relies in part on a good skimmer and ozone. I have been through THREE of the Aqua-Zone Plus models in 18months, two replaced under warranty, I'm waiting to hear on the last. I am told by Red Sea they don't like humid environments, like around aquariums ...?!!!  
<this is a big peeve of mine too <G>>
Does anybody make a comparable unit that can survive in such an environment and doesn't need its air "pre-treated"?  Thanks a bunch, Steve.
<there are two problems here that need addressed, Steve. The first is that most (all as I can see) hobby grade ozonizers on the market are very poorly made IMO. Very (!) poorly made. That any aquarium instruments made are not tolerant of humidity is ridiculous and simply staggering to me. There is good news though. While the aquarium hobby seems to have an endless stream of consumers that will buy inferior equipment and keep some merchants in business without forcing them to improve or get out... the Aquaculture industry does not tolerate this. Profit margins with fish farmers are leaner (price per pound for food fishes vs. ornamental fishes... no comparison). They are also much harder on their equipment in working hatcheries and as such demand industrial grade gear. Savvy aquarists as you are now :) learn to seek cheaper and better made gear from aquaculture suppliers. You can do general searches online for folks that supply such equipment, but I recall a few brands like Ozotech that crossover and are sold by a aquarium hobby merchants like CustomAquatic.com. DO look for Ozotech... I have used them for years and find them to be an affordable and durable brand. The second problem you/we encounter is the style of generator - some require dry air (corona discharge models), while the better ones IMO do not (electronic generated). Do seek the latter. kindly, Anthony>

pH and ORP questions 2/11/05
Great site! ...and again, thanks for all the help and advice.
<Glad to!>
My 300g tank has been running for about 7 months, and I'm running into I'm sure some normal issues. I've got 5 species of soft corals (total of 15 corals), and they seem to be acting OK. Sometimes they will curl up (Lobophyton) or balloon up (colt), but I think they are going through normal respiration cycles. The next day, or even several hours later, they are back to normal. Maybe I'm wrong. I've got 4 yellow tangs, 2 clowns, 5 damsels, and a Dottyback. The fish act completely normal. 
<Sounds normal.>
The challenge is keeping pH and ORP up. I recently got a Milwaukee pH/ORP controller, and have frequently calibrated it to make sure readings are accurate. pH stays between 7.8 at night and 8.1 during the day. Way low, so I have been dosing Kalkwasser several times each day (2 qt RO water with 2 tsp Kalk dissolved for several hours). pH rises maybe one point with each dosage, but not much. 
<This is a common problem. Have you taken a sample of your tank water outdoors, aerated it well and then re-tested pH? If it rises significantly, you have CO2 accumulating in your tank. This is common, especially in newer "tighter" houses that get less fresh air moving through.>
Alkalinity is 16 dKH. I use Kent Marine buffer, which does raise pH, too, but I don't want to get buffer too high just to raise pH...therefore have been trying Kalkwasser. 
<Wowza! Definitely discontinue any buffer additions, and check your calcium. You may have to add just calcium for a while until calcium and alkalinity are back in balance.>
ORP is around 180 (day) - 190(night). Also way low. I just re-measured ammonia, nitrite, and nitrate, and all are 0. I've been doing 18g water changes weekly, and have been doing it twice a week for the last several. Yesterday, I did a 54g water change. Today, the ORP meter says 183. I'm using tap water because it is quite hard here in Phoenix. The ORP meter shows raw tap water at around 220. My RO water is about the same. I've been using Oceanic salt, but switched to Tropic Marin a few weeks ago. I'm thinking of switching to Instant Ocean to save on cost.  I do have some brownish algae on the gravel (not thick and fluffy, but just growing on the gravel). If I stir it up, the next day the algae is there again. I also have quite a number of little white tubular sponges growing in the shadowy places in the tank. I'm assuming all of this is from high nutrients/diatoms in the water, and would probably go away if I can keep pH up. 
<The brown "algae" on the gravel is probably diatoms. Higher pH will probably discourage their growth, but they only require tiny amounts of silica, so trying to control them by limiting silica is probably futile.>
I have an ETSS protein skimmer. I have to clean out the cup at least every other day because of the dark brown grunge that is collected. I assume that it is operating effectively. It's water is drawn from a surface overflow to ensure surface water is what is skimmed. A month ago, I introduced 7 ounces of carbon into the overflow that the skimmer effluent flows over, as well as the rest of the overflow water. I changed the carbon last week. 
<Sounds good. With so much production from your skimmer, I wonder about your feeding regime. Does a lot of food go uneaten?>
I've got 300lb of live rock, and a 4 inch aragonite gravel bed (not oolitic sand unfortunately, but the next grade up). There are 4 MAK4 pumps connected to a 1.5" "Anthony manifold" (you've gotta trademark that :) ) that goes around the perimeter of the surface. I estimate water circulation around 4000-5000 gph.
<Also sounds good. I will pass along your trademark suggestion to Anthony, though he is far too generous with his intellectual capital to even consider it.>
The only thing I haven't tried is ozone. Please advise on how to keep pH and ORP up. Regards, Jerry 
<Ozone has it's place, but you must also address the underlying issue. Perform the pH experiment described above. If the pH rises more than .2 units, try slightly opening a window in the room where your tank is and see how the pH and ORP react after a day or two. Also watch the ORP as alkalinity falls, as this may be affecting the result as well. Best Regards. AdamC.>

Protein Skimmers And Ozone - 07/25/05
Bob,
<<Eric R. here...>>
What is the proper tuning of a protein skimmer that has ozone injected since the waste appears much clearer.
<<"Tuning" is no different than without ozone.  You still want a thick dark skimmate, unless you're skimming "thin" for a reason (e.g.- fighting nuisance algae).  I noticed the same as you when I first added ozone...skimmate became lighter in color...and less of it.  I discovered this was due to less air being processed by the venturi on the pump to which the ozonizer was connected...in other words...the ozone didn't lessen my skimmate, the skimmer just wasn't performing as well as before.  By not using an air dryer and ensuring tubing diameter was maximized, I was able to keep the air restriction of the venturi to a minimum and restore the performance of the skimmer.  Removing/not using a dryer may not be the best option depending on the size and type (hot corona vs. cold corona, UV, etc.) ozone generator you are employing.  In this case you can try adding a tee-fitting to the pump venturi to allow more air to be drawn in.>>
Regards,
John