Iron (rust) Contirbutor to Hair Algae?

[WarSea378]

I recently posted about a hair algea problem and got some great feedback.

http://www.bostonreefers.org/forums/showthread.php?116540-Hair-Algae-Removal-Product-Help

Since then I have found a source saying that iron or rust can contribute to hair algae formation. Does anyone have any info on this. I am not aware of any issues concerning this.

 

[IPWitan]

I haven't read the link, but that is surprising. As I recall, some of the phosphate absorbing compounds are iron based. As I recall, some forms of iron bond to phosphates. I even thought there was an old trick to let a nail rust in your tank to help absorb phosphates. Hopefully someone with actual knowledge of this will chime in.

 

[inverted]

Certainly could. there's been a fair amount of studies on iron as a limiting trace element for algae. If you think about it, some people have tremendously high nitrate and phosphate, but no algae. So, there has to be some other limitation. Often it's what we don't test for that's most important. Iron is just one of many possibilities, but here is a write up about recent study on iron induced "black reefs".

http://newswatch.nationalgeographic.com/2011/09/01/black-reefs-when-the-ship-hits-the-reef/

 

[jarrodsanborn]

for a while i was running a macro algae dense reef tank..... almost more plants than water. I had to dose bottled iron to keep it going.

 

[WarSea378]

Wow, this seems like a subject that needs more study (on my part). I have a clip that holds my return from the refugium/sump and I noticed it had rusted, I didn't ever think anything of it until I saw the article. I didn't think much of it because it seemed to be a small thing, but I suppose that doesn't mean much.

 

[WarSea378]

Inverted, that article is eye opening! I can't imagine the damage done all over the world over the last hundred years or so (not including the obvious such as oil). I am replacing that clip as soon as I get home.

 

[IPWitan]

I am curious about this article, as iron oxide is used to reduce phosphate levels, at least according to this article. http://www.advancedaquarist.com/2004/6/review and http://reefkeeping.com/issues/2004-11/rhf/index.php

Maybe in the ocean there is no phosphate, so it doesn't bind to anything and hurts the corals.

 

[inverted]

I am curious about this article, as iron oxide is used to reduce phosphate levels, at least according to this article. http://www.advancedaquarist.com/2004/6/review and http://reefkeeping.com/issues/2004-11/rhf/index.php

Maybe in the ocean there is no phosphate, so it doesn't bind to anything and hurts the corals.

Iron in itself doesn't really bind phosphate. Algae really needs ionic forms of iron. GFO is a very specific granular form of iron, too large to be used by algae directly. The large granules, certainly are not going to pass through the cell walls, they are quite a bit bigger than micro-algae cells for example. And ionic forms of iron won't bind phosphate, to any significant degree and wouldn't lock it up like GFO does. GFO could break down into ionic iron, for example. This is one reason why it's recommended to use very low flow, so, that the GFO particles do not grind together and become pulverized. Also, when used in a reactor, usually screens are used to prevent the granules from leaving the reactor and entering the system, where they could degrade into ionic forms of iron.

Also, just to clarify, there isn't evidence that iron harms corals directly. This is a bit off topic and overly generalized... However, more or less, what it does, is drives algae, which releases organic carbon as a byproduct, which drives bacteria, which for various indirect reasons can harm the corals. This then allows the algae to overgrow the corals.