Looking for info on Iron as a "Reducer"

[JustinReef]

Basically Im interested in learning more about what may or may not be going on in my reef...

I keep a decent amount of macro algae (mostly Caulpera) in my display tank along with a few leathers and other softies. I have kept a few tanks like this over the years and been relatively successful with keeping Caulpera happy and never seen it go sexual. I had always contributed that to regular pruning, harvesting and dosing Iron.

In my newer set up, I began running ozone and ever since I seem to be researching ozone, ORP, Oxidizers, reducers, ect. ect. It has literally made my head hurt at times trying to understand all the intricacies of ORP and ozone! Anyways, I recently learned that iron is listed as a reducer...After more and more research I decided to try running my reef without dosing iron at all. To make a long story short, within 2 weeks, I had macro algae dying off and looking very unhappy. I began dosing iron again and all was back to normal and the Caulpera regained its dark green color. So...What does this mean? Obviously my macro needs the iron but is it also decreasing the quality of the water? Is the ozone "removing" the iron? I honestly I have not been able to wrap my head around this.

My feeling is that like always, I need to find that balance and try to keep things steady. Which seems to be dosing iron as I had been for months and also running ozone at the levels I had been for months. I try to keep the ozone running steadily but not in huge amounts. It never actually turns off because I have the ORP set point up at 400 but only keep the ozone on enough to have it stay around 300-350. The amount of ozone I run never seems to be able to get the tank to an ORP of 400...If this is relevant at all

I have been very happy with what I consider stability and health of my tank. Lots of growth and happy fish/corals but...I would love to understand what is going on exactly here and if its safe or good long term.

Thanks!

 

[Randy Holmes-Farley]

Iron is present in two forms: Fe++ which is a reducer, and Fe+++, which is a very weak oxidizer.

I am happy to answer any specific questions that you have, but there is no problem using ozone and iron at the same time, although the ozone may make the iron additions less effective as they convert more soluble Fe++ to less soluble Fe+++. I use both iron and ozone.

Have you read these articles?
Ozone and the Reef Aquarium, Part 1: Chemistry and Biochemistry
http://reefkeeping.com/issues/2006-03/rhf/index.php

Ozone and the Reef Aquarium, Part 2: Equipment and Safety
http://reefkeeping.com/issues/2006-04/rhf/index.php

Ozone and the Reef Aquarium, Part 3: Changes in a Reef Aquarium upon Initiating Ozone
http://reefkeeping.com/issues/2006-05/rhf/index.php

ORP and the Reef Aquarium
http://www.reefkeeping.com/issues/2003-12/rhf/feature/index.php

First Iron Article: Macroalgae and Dosing Recommendations
http://www.advancedaquarist.com/issues/aug2002/chem.htm

Second Iron Article: Iron: A Look at Organisms Other than Macroalgae
http://www.advancedaquarist.com/issues/oct2002/chem.htm

 

[JustinReef]

Thanks Randy. I have read the ozone articles, the ORP and reef aquarium article but not the others. I will do so today.

My aquarium has been doing very well with both iron dosing and running ozone but then I started thinking that maybe all I was doing was dosing iron and then removing it with the ozone.

Thanks for the articles

 

[Randy Holmes-Farley]

It is certainly possible the ozone is contributing to iron depletion, but that doesn't mean it isn't useful anyway. Maybe more useful.

 

[JustinReef]

Ok, good to know. Whatever the case, things seem to be working really well for both my macro and soft corals, so I don't want to change anything at this point.

I have noticed that the macro has slowed in growth a little since I started running ozone all the time. I used to just run it once a month or so to clear up the water but now I run it all the time in low amounts. Basically so it never reaches the target ORP and therefore never shuts off. Macro still grows well but not as much and the bit if hair algae I had is dying off quite quickly now.

 

[Randy Holmes-Farley]

Mine never reaches excessive ORP and never shuts off either. I prefer it that way since it is incredibly unlikely to ever overdose the tank by accident.

 

[JustinReef]

I actually have an ozone question that maybe you might be able to help me with. I recently switched from an older 100 mg/hr ozonizer with a seperate ORP probe to a 200 mg/hr Red Sea unit with the ORP built in. I have had the new one set up for a week. When I set it up, the probe would not get a reading higher than about 50 but since it was new, I assumed it just was going through a break in period. The thing I found weird though is that if I set the ORP target level to the highest it would go, it only reached 110 or so. Its been a week and still the highest ORP target I can get is about 110. Im quite confused as to what is going on. The ORP is still only reading about 60 in the tank. Do you have any idea what could be going on?

Hope that makes sense

 

[Randy Holmes-Farley]

I'd look to see if it needs calibrating or even functions at all. If it has been in the water for a couple of days, and the ORP is only 60, I think there may be an error.

 

[JustinReef]

Even if the probe is not functional though, shouldn't the ORP set point be able to be set higher than 110? Or is it relative to what the current ORP is? I thought I should still be able to set the unit to say 380 regardless of what the ORP reading is.