Here has been my experience so far with ozone.
600 Gallon display - 100 gallon sump probably 650 total water volume with rock displacement
Tank was setup a little over 6 weeks ago and using ozone from day 1. Absolute necessity is a flowmeter.
Per the instructions it states
Ideal airflow rate 2-10 Standard Cubic Feet per Hour (SCFH). I split the difference at 3LPM (conversion calculator
here).
First I tried to just use the second input from my silencer on my skimmer and having the other line go through my CO2 scrubber. This registered 0 on the flowmeter. I then just tried to run all air through the ozone generator but this restricted too much flow and didn't allow enough air into the skimmer. Skimmer is a Reef Octopus 300-Int. I now have the intake line split near the ozone generator so most the air pulls through my CO2 reactor and the other line goes through the flowmeter which can adjust the air input with the dial on bottom. Pushing the air through the line is a Whisper air pump that turns on when the Ozone generator turns on and turns off 1 minute after the generator shuts off so the line gets cleared from ozone. Moral of the story, I have a beast skimmer and it was not able to pull enough air through the ozone generator without an air pump. I will say though that my air input lines to my skimmer are long and go through a CO2 reactor and pull fresh air from outside. It may work if your ozone generator is right next to the air input of the skimmer but in my system its not. Air pump was needed.
Now on to usage.
I watched a ton of videos on ozone and the common theme of those who ran it on multiple systems with hundreds if not thousands of gallons was this - less is more. They were running it anywhere from 10 minutes a day to 1 hour a day. The videos I saw where it nuked tanks, smaller systems, running it too long. Like RHF said the whole point is water clarity. I only use ORP as my safety net, not my control point. If my ORP gets above 350 the ozone does not run. If my skimmer is off my ozone does not run. I also run all my return water from the sump through a UV sterilizer and from what I read UV breaks down ozone so it never makes it to my display. If the UV is not on the ozone doesn't run.
Here is my APEX code for the generator:
For my system my water is crystal clear running it 1 hour at night. I started out 10 minutes, then 20, etc until I got to 1 hour making sure everything is safe. I am also starting to run it for 10min every 4 hours to stop the "fishy" or ocean smell in my room.
I have the air pump pushing air through a BRS air dryer with desiccant (I live in FL, humid), through the flow meter into the ozone reactor into the skimmer and the skimmer has a
recirculating lid with the output going into another reactor full of carbon to filter out the ozone.
ORP
Here is what I noticed. The first couple of days the ORP shot up 15 points or so when running the ozone then it gradually went back down. For about 3 weeks it did nothing when the ozone was on. Now that the ORP probe is "broke in" (from my research) the ORP goes up 15-20 points when it runs at night and it has been steadily climbing the last couple of weeks. Like I said though, IMO I don't think its a good idea to control ozone with ORP, just use it as a safety net. I use my eyeballs to control it. I have my pool cage viewable from the long side of my tank which has white beams. If the white beams dont look white when looking through my tank I will turn up the ozone, if they stay white I turn it down until they start to not look as white. I aim to decrease usage not increase it. Tank is clear at 2 on the dial and 1 hour at night for me. You can also take 2 5 gallon buckets. Put a gallon or 2 of freshly mixed saltwater into 1 bucket and take a gallon or 2 of tank water and place it in the other bucket. If they dont look the same then you need to increase ozone.
Hope this helps!
Kris
