On 23/2/97 8:38 PM, Mike Roberts wrote:
>Well I appreciate the responses I received about UV sterilizers and protein
>skimmers. Here is my last question about adapting various reef
>the hi-tech plant aqaurium:
> What about Ozone with an ORP controller? any benefit in a heavily planted
As the person who made a posting some time ago about how he was running a
plant tank on principles borrowed from reef tanks, and who claimed that
Delbeek and Sprung's "The Reef Aquarium" was a good guide for planted
tanks, my understanding is that ozone will do 2 things - increase the
redox potential of the water, and remove colouration from organics.
I have really clear water with no trace of colouration in my planted tank
which runs without a filter. The plants do a wonderful job of removing a
lot of organics on their own, and I see little reason to add ozone for
that. It's probably cheaper and a lot easier just to toss a bag of
activated carbon, or Purigen, into the back of the tank if needed. Julian
Sprung recommends a bag of carbon just placed in the sump of a reef tank
to clean up yellowing of the water from organics. I've tried this in my
tank before it was anywhere near as planted as it now is, and when I had
wood leaching tannins into the water, and it cleared up the water
extremely well. You definitely don't need to place it in a filter and
force water through it.
In relation to redox potential, I think what occurs is as follows (but
I'm willing to be corrected).
Our fish produce wastes like ammonia, and other organic wastes also get
into the system from the fish and from decay of plant material, dead
fish, etc. These wastes can get removed by one of 2 means -oxidation
processes or other processes which include plant photosynthesis.
Oxidation processes (ammonia to nitrite to nitrate for example, and
phosphorous compounds to phosphate) consume oxygen and lower the redox
potential. Photosynthesis produces oxygen and does not lower the redox
Ozone also produces an oxidation process, but the breakdown of ozone (O3)
into a free oxygen atom which drives the oxidation, and an oxygen (O2)
molecule, adds oxygen to the system and does not reduce the redox
In other words, the use of plants to deal with waste products reduces the
quantum of oxidation processes occurring in the tank and thereby promotes
an elevated redox potential. Heavy planting should therefore make the use
of ozone redundant.
As I understand Sprung's approach to ORP and redox in reef tanks, it is
that it can help but you're better off getting redox to acceptable levels
through good tank management than by adding lots of technology. He also
runs the line that what counts is how the tank inhabitants (including
plants in our case) are going, not blind adherence to tinkering to get
the numbers right. People can become fixated on getting the numbers right
while the tank actually goes downhill.
I would agree with that. If the tank looks healthy, and stays healthy,
keep with what you're doing and learn from what helps and what hinders
your results. Keeping things simple is cheaper and means less
maintenance. I think it's a lot more satisfying in the long run.
Where I think lots of technology becomes useful is if, for some reason,
you _need_ to keep a higher fish load than the tank will support (eg a
wholesaler's fish holding system), or you must work with some other
marginal situation for some reason, and you absolutely have to rely on
every bit of technology around to keep it going. That's not the way to go
about enjoying your tank as a hobby - that's hard work!