coralline algae myth?

[fambrough]

I have seen it mentioned recently in more than one thread that growth of coralline algae on live rock reduces its effectiveness as a biological filter. This just sounds like such utter theoretical hogwash to me. Does anyone have any empirical data to support this claim? Or is this another reek keeping myth that gets bandied about every now and again?

I'm not trying to get anything started here. I just thought that if I were wrong, someone might point me to some analysis and data to support the claim.

Thanks.

[seapug]

I've never heard that and it goes against everything I've ever read and experienced with it. Coralline algae growth is one of the best indicators that your water quality is good and your system is healthy.

Can someone refute this with real evidence?

[m2434]

Some people have theorized that it can block the pores and prevent water exchange to the deeper parts of the rock. I have no idea if this is true. I also have no idea if the deeper parts of the rock are responsible for denitrification - it has been theorized, and readily accepted, but as far as I know, never proven. Who knows? It could be the coralline is consuming the nitrates

I strongly believe that coralline growth is not an issue, but I certainly can't prove that with 100% certainty. Maybe it's just that no rocks are ever 100% covered with coralline, but there is actually a slight decline in denitrification. Or maybe the coralline seals off the rock creating more anerobic areas, thereby increasing denitrification.

I don't think anyone knows for sure. I believe that the coralline theory was created to explain "old tank syndrome", but I don't think there is much actual research on either.

[CleveYank]

huh? This is new lore to me, not sure where you saw that.

Respectfully stated.

If the natural reef does it and some of the best captive examples of the natural reef do it? Then I would have to say the coralline growth inhibiting bioactivity to a negative impact on reef and overall specimen health due to decreased bio metabolism capacity assumption is a bunch of bunk.

[LobsterOfJustice]

I think the basis behind that "myth" is that the coralline blocks all the pores in the rocks. It essentially makes it less porous.

I think this is true, but to an extent that doesn't make a difference. All the areas of the rock that are not exposed to light will not be sealed over.

[m2434]

I think it's safe to say reefs can be verry successful regardless of coralline growth. The idea that it reduces LR's effectiveness is a theoretical non-issue. After all, have you ever seen a rock 100% covered?

[CleveYank]

Originally posted by m2434
I think it's safe to say reefs can be verry successful regardless of coralline growth. The idea that it reduces LR's effectiveness is a theoretical non-issue. After all, have you ever seen a rock 100% covered?

Now if I may chime in again, never seen a rock completely covered. And I have certainly never heard of anyone with 2 to 3 reactors and dosing and perfect tank post...OH MY GOSH, I have Coralline for the past 4 years and my tank recycled!!!!
HOWEVER,
What I could think within the very good door of an observation pointed out by fambrough's post is that.

You know this whole anaerobic or lower O2 depleted state that the plenum and sandbed and slow pass nitrate filter proponents talk about?

The encrusted areas of liverock if we go head long into oxygen lowering or inhibiting due to coralline growth. Now that is a possiblity linked with fambrough's inquiry that I would not just cross out without consideration.

Maybe it's another location for the "natural" means in which the ocean via lower O2 bacterias remove toxins. Maybe there is a balance that is achieved within the rock that we don't even have a full grasp of. Nitrate reduction within. And of course would be hard to prove since if coralline causes a change over in the efficiency and type of bacteria. But I have never heard of someones tank recycling with a fantastic coralline coverage. And when I have heard of tanks with the old tank syndrome. There was usually something accumulating or more than likely they did not account for the many 2 inch fish that had become 8 inch fish.

As things in nature are applied through what survives and what is usually required. You never know, that coralline and a tank that has lots of it and looks like a chunk of the GBR or Bali yanked out and dropped in big glass cube just might be so successful due to that unknown relationship of aerobic and anaerobic. But does coralline growth deter that tank's liverock or be enough to inhibit to crashes or declines? Again, no way Jose.

[Randy Holmes-Farley]

Coralline is usually only on the exposed surface of the uppermost rocks. Other surfaces are uncovered.

[nemonick84]

I would imagine that if one's tank contains an adequate amount of live rock then the small amount of encrusting coraline algae covering the limited amount of surface area that it does would not be an issue. Maybe in a nano tank with no alternate means of biological filtration, featuring a single piece of live rock with a top-half completely covered in coraline; this might have an adverse effect on water quality. But I could never imagine any other circumstance in which denitrification would be reduced due to coraline-encrusted live rock.

Nick

[seapug]

The more I think about this topic, the more ridiculous it becomes. If your rocks are covered with coralline algae to the extend that it interferes with the biological filtration, your water quality would decline, nutrient levels would rise and the coralline algae would die.

In summary,

[mille239]

Lol! nice analogy.

[m2434]

Originally posted by seapug
The more I think about this topic, the more ridiculous it becomes. If your rocks are covered with coralline algae to the extend that it interferes with the biological filtration, your water quality would decline, nutrient levels would rise and the coralline algae would die.

In summary,

I don't see why coralline would interfere with nitrification, I think the idea is limited to just denitrification. So, nitrates might increase, but sadly, I've seen tanks with better coralline growth than mine, that have very high nitrate levels. Therefore, I'm not sure the coralline would die off..

Either way, IMO, your summary is perfect

[fambrough]

So far the replies are just as I have suspected and along my own line of thinking.

I have wondered about this in the past, but more recently was inclined to call out at least two individuals who were espousing the theory. But that ain't my modus operandi , generally speaking. So I didn't interrupt when I saw the spewing bunk wash over the naive, smelling to them for all the world like good advice and words from the masters.

The only time (that I can think of) when I couldn't hold my tongue was about that whole tumbling chaeto thing. Ooops. There was this other time recently when I told people they didn't know what they were talking about when they insisted on mispronouncing chaetomorpha. Hmm. Maybe time for some self-reflection.

Anywayyyyy. Back to the myth at hand. Thank you all for your thoughts. I suppose without the firm data, we shall never know. At the end of the day, it is good to contemplate all things, even mad things. They, too, can lead to genius.

a tout a l'heure

[lakee911]

Originally posted by seapug

In summary,

I'm confused... is the bread supposed to be rock and the bologna the coraline?

[SCR]

Originally posted by lakee911
I'm confused... is the bread supposed to be rock and the bologna the coraline?

Yes, you could say that.

[seapug]

yes, but notice the bologna only covers part of the exposed bread surface. If the bologna completely covered the bread it would interfere with it's deliciousness.

[lakee911]

LOL

[George Grogan]

Originally posted by seapug
The more I think about this topic, the more ridiculous it becomes. If your rocks are covered with coralline algae to the extend that it interferes with the biological filtration, your water quality would decline, nutrient levels would rise and the coralline algae would die.

In summary,

Well stated... great analogy!

[Tommy3492]

but does not coralline grow at deep depths in the ocean?? so the sun does not penetrate the rock as much so maybe the rock is fully covered down there, but in a reef tank, alot of the rock is exposed to MH lights, leaving space were no coralline grows, so could not the water still get deep down into the rock through the gaps?

[Randy Holmes-Farley]

The reef species that do grow well in reef tanks in lit areas typically do not grow in dark areas in rocks in reef tanks because there is not enough light. There is plenty of water flow in most cases, but not enough light for the species that are present. Those species may be very different than those that thrive in the ocean, or other aspects of the situation may be different. Simple rate of growth may be part of the explanation. If it takes 5 years to grow to cover a rock that is 50 feet down in the ocean, it may never be noticed at all under an overhang in a reef tank, even if growing at the same rate.