Carbon and Ozone

hawkinsrgk · Dec 2, 2014

Hello All

I have been been reading about the use of ozone in order to decide if this is something that I would like to get into.

I do not have a clear understanding on how much carbon to use post ozone reactor. For example this is my understanding from what I have read.

1. I read these three articles

Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry
Ozone and the Reef Aquarium, Part 2: Equipment and Safety
Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone

In one of the articles Randy talks about a DIY ozone reactor that is a 4 inch PVC pipe 20 inches long that is used for carbon. From what I calculated that comes to 1.09 Gallons so say 1 gallon

2. On the Avast web site it implies that 12 cups ~ .75 gallons of carbon should be used.
3. In another article that I read (Old article not by Randy) it suggests to use 3-6 ounces of carbon.

So with all of that being said, does that mean that it was once thought that a lot less carbon was needed than actually is?

I guess the real question is why is so much carbon needed post ozone reactor? I get the toxic part and why it is needed, but not why so much is needed. Currently my total water volume is around 380-400 gallons. I use 2 cups of carbon and change it out about every three weeks. The costs of 3/4 to 1 gallon of carbon every 2-4 weeks would be very expensive.

Thanks
Randy

Randy Holmes-Farley · Dec 2, 2014

Different people have different tolerances for ozone and the oxidation products getting into the display tank. Some do not use any carbon, but just run the ozone into a skimmer. I wanted to be sure none got through, and it didn't. A lot of people don't bother to measure to see if they get through the carbon.

That all said, I think ozone has fallen out of common use. Even I do not use it much any more, and few people do use it.

once every couple of months or so, I trickle a very small amount into my skimmer with no GAC to remove yellowing compounds from the water, but that's it.

One concern is HLLE caused perhaps by products of the ozone, or from the GAC itself. Tjhat's one reason I switched to a better GAC (ROX) now for my normal water treatment, and no ,longer use the ozone, and I have had no issues with HLLE when before I did (although these are different fish now).

FWIW, I don't think the GAC used in ozone effluent needs to be frequently changed, but one can use a test kit to see if it is adequately sized and is functioning still.