Algae derived Reactive Oxygen Species

[Brummie]

Hi all. I've been running an algae scrubber now for two years and to my surprise I find I no longer require activated carbon to keep my water crystal clear. I've been researching algae production of Reactive Oxygen Species and the possible link between hydrocarbon destruction and ROS production.

Just a quick question, is there a safe way to remove substances such as hydrogen peroxide from the display tank water whist not affecting any other compounds. For example, would aggressive skimming remove it?

Thanks in advance

Gary

 

[Randy Holmes-Farley]

It is generally thought that ORP is actually lowered with lots of algae growth in a reef tank, not raised. Algae often release a fair amount of organic matter. Perhaps we don't generally get a lot of the species that release much ROS. Or perhaps we are wrong, which wouldn't be the first time reefers had a chemistry misunderstanding of a complex phenomenon.

I wouldn't be convinced that there is any concern (even people using ozone with GAC seem to have relatively few issues that are apparent tot he aquarist), but both GAC and GFO may well catalytically break down reactive oxygen species, and that's what I'd experiment with if I wanted to.

 

[Brummie]

Cheers Randy. I'm wondering whether the reduced ORP has been measured on macro algae beds and not high intensity scrubbers. It seems there may be a link between iron deficiency, allelopathic compounds and ROS.

http://www.sciencedirect.com/science/article/pii/S004565351100734X

http://www.whoi.edu/fileserver.do?id=36850&pt=2&p=28251

I'm just trying to explain to myself why my water is not yellow. W Adey has posted a report which describes the destruction of volatile hydrocarbons through excess O2 production and UV light, but as far as I know, I'm not supplying UV light.

"Toxic Organics

Combined with solar ultraviolet, ATS systems with high oxygen supersaturation break down entrained hydrocarbons. There is an extensive general research literature on this process, and a single ATS research study in the late 1990's demonstrated that when combined with artificial ultraviolet, ATS systems have considerable capability of breaking down a variety of chlorinated hydrocarbons. Additional research is necessary in this area, as a single study, even with a considerable laboratory support, cannot provide the basis for systems engineering; however, it is likely that if ATS is carried out at very large scale to produce bioenergy, it will significantly reduce toxic hydrocarbons in aquatic environments and ultimately the ocean."

http://www.physicsegypt.org/epc08/epc823.pdf

 

[Randy Holmes-Farley]

It could be that folks have not looked closely at ORP in brightly lit systems vs the same system without the brightly lit macroalgae.

Ultraviolet alone would certainly produce oxidizing events. Adding in the ATS may not be needed.

I'm just trying to explain to myself why my water is not yellow.

How do you know it is not? Almost everyone who tries ozone thought their water was clear until they used it and saw the difference.

 

[Brummie]

He he. I've had this system in various guises for 12 years and the water has never looked so un-yellow. I feel a "water clarity competition" is on the cards but this is not necessarily good for systems anyway in my view. Everything needs food, after all

 

[Randy Holmes-Farley]

FWIW, people using UV sterilizers claim it de-yellows the water, so an ATS using anything with UV (like in the link) may also accomplish that same task.

How are you lighting macroalgae?

 

[Brummie]

Got 87watts of Chinese 630 to 660nm and 450nm LEDs on a 13 x 10 inch screen at the minute but 50watts of the same light seems to produce the same effect.

 

[Randy Holmes-Farley]

Well, I guess I'd just be happy with the result.

 

[Brummie]

Ok, cheers Randy. Love your research btw. Your articles have made the complicated, available to normal folks like me and am honestly grateful.

 

[Randy Holmes-Farley]

You're welcome and thanks.

Happy Reefing.