Interesting discussion on how ATS can be poisonous

[FlyPenFly]

Interesting discussion here about how ATS can be poisonous.

http://www.thereeftank.com/forums/f2...rs-213031.html

[SantaMonica]

They don't understand that algae provide all the filtration on reefs; there are no waterchanges, because reef water is basically 100% recirculated among itself. Algae is 90% of the biomass in the ocean (except bacteria). But they don't read these studies, or even a basic marine biology book, like "Introduction To Marine Biology", by Turner Small.

Also they don't understand that scrubbers have a much higher level of photosynthesis (filtering) than just macros.

And they don't understand that organic phosphates are called "food".

And they don't read studies showing the amount of macro algae on reefs (up to 10kg wet weight per square meter).

And they didn't read about the ATS and the public aquariums...




Great Barrier Reef Aquarium

Many people say how the Great Barrier Reef aquarium was a scrubber "failure" because the corals did poorly. Apparently these people have not done much reading. In the early days of that aquarium, the scrubber was doing it's job great:

1988:

Nutrient Cycling In The Great Barrier Reef Aquarium
http://www.reefbase.org/download/dow...10&docid=10506

"The Reef Tank represents the first application of algal scrubber technology to large volume aquarium systems. Aquaria using conventional water purification methods (e.g. bacterial filters) generally have nutrient levels in parts per million, while algal scrubbers have
maintained parts per billion concentrations [much lower], despite heavy biological loading in the Reef Tank. The success of the algal scrubbers in maintaining suitable water quality for a coral reef was demonstrated in the observed spawning of scleractinian corals and many other tank inhabitants."

But did you know that they did not add calcium? That's right, in 1988 they did not know that calcium needed to be added to a reef tank. Even five years after that, the Pittsburgh Zoo was just starting to test a "mesocosm" scrubber reef tank to see if calcium levels would drop:

1993:

An Introduction to the Biogeochemical Cycling of Calcium and Substitutive Strontium in Living Coral Reef Mesocosms
http://onlinelibrary.wiley.com/doi/1...20505/abstract

"It was hypothesized that Ca2+ and the substitutive elements Sr2+ and Mg2+ might [!] have reduced concentrations in a coral reef microcosm due to continuous reuse of the same seawater as a consequence of the recycling process inherent in the coral reef mesocosm."

"The scleractinians (Montastrea, Madracis, Porites, Diploria, and Acropora) and calcareous alga (Halimeda and others) present in the coral reef mesocosm are the most likely organisms responsible for the significant reduction in concentration of the Ca2+ and Sr2+ cations."

"Ca is not normally a biolimiting element, and strontium is never a biolimiting element;
HCO3 [alk] can be. It appears that, because of a minor [!] limitation in the design parameters of the mesocosm, these elements and compounds may have become limiting factors. [...] It is surprising that the organisms could deplete the thousands of gallons of seawater (three to six thousand) of these elements even within two or more years [!!].

"The calcification processes are little understood."

So then in the late 90's, the Barrier Reef aquarium start using up it's supply of calcium, and the folks there said "the corals grew poorly". Really. No calcium, and the corals grew poorly. So they "removed the scrubbers" and "experimented with the addition of calcium" sometime after 1998. Then in 2004 it "definitely improved a lot". Really.


Talks about calcium was not added to barrier aq:
http://en.microcosmaquariumexplorer...._Reef_Aquarium

[RkyRickstr]

Well, not all of the filtration. There is bacteria which plays a huge roll along with sponges and such.

[SantaMonica]

Most bacteria are heterotrophic. They don't do any filtering; they only add to the bioload. Only chlorophyll does filtering.

[Doug G]

I think the bacteria could do a vital role in breaking down certain toxins. For example, the old nitrogen cycle thing we all learned about ammonia from livestock being broken down to less toxic nitrite and then nitrate.

[Doug G]

Hmmmm, read the thread referenced above. Sounds like all the same old theorizing and logic trails to try and prove one's way is the right way. Yawn.

[Ptyochromis]

Chlorodesmis fastigiata (maiden's hair algae) is known to be poisonous to coral. It produces competitor suppressing chemicals that can bleach coral on contact with the plant. It's no surprise that many algae would develop ways to gain a competitive advantage.

Hmmmm, read the thread referenced above. Sounds like all the same old theorizing and logic trails to try and prove one's way is the right way. Yawn.

Indeed, there should be a more objective approach. Trying to prove you hypothesis wrong is a much better way to go about things. Null hypothesis best hypothesis. You arguably learn more by being wrong.

Either way, there is much that we are still learning about the oceans and relationships between organisms. With all the effort being put into researching reefs, I'm sure we are going to discover more allelopathic interactions among organism.

[SantaMonica]

It's nice that scrubber algae does not touch anything.

[rleahaines]

The Great Barrier Reef Aquarium used an algae scrubber for quite a while as a major part of their filtration system. What they did, although using trays of algae, was not the same application as an ATS. They actually didn't harvest the algae to export nutrients in the same way users of the ATS systems we discuss on this site do.

Instead they used the algae mats as filters and as a way to stabilize their large saltwater system. It worked for them for quite a few years until they had a crash of the system, which could have been caused by a number of things.

They also got their replacement water directly from the ocean.

There are many different kinds of algae and many different kinds of coral. Some coral grows well with algae, some types are killed by algae. Some types of algae will overgrow coral, some kinds don't. Some kinds of coral don't work in our systems with other kinds of corals as they compete against each other.

The issue here is that ATS systems do work and work well, but you need to pay attention to other issues in your tank when you try to emulate what is going on in a natural environment in an unnatural one of a tank.