I note tim your misguided attack on ATS is an indirect attack on me. That's fine.
Firstly tim, I'll point out that I don't consider you anywhere in the realm of an elite reef aquarium hobbyist (a portrayal of yourself that you attempt to project everywhere) no matter how many links to scientific papers you provide, & no matter how many boring rants you produce.
On the matter of attacking "turf algae", I don't grow turf algae on my scrubber screen, & I don't know of anyone doing so, at least on a modern 'Algae Scrubber'.
I'm curious how you've determined no one has any turf algae species in their ATS? Irregardless. If you had read the links I posted the research done by scientists I posted links includes "foliacious" alga as well. The research clearly identifies the labile DOC or Dissolved Combined Neutral Sugars (DCNS) released by alga as promoting pathogenic
In any case, lets discuss "turf algae"!
What is "turf algae" ?
Turf algae are multispecies assemblages of diminutive, mostly filamentous algae that attain a vertical height of only 1 mm to 2 cm (Figure 1). Turf algae often exist as assemblages (algal turfs), are ubiquitous in reef systems and are composed of the small, juvenile stages of macroalgae (e.g., Gelidium spp., Gelidiella spp., Digenia simplex) along with faster-growing filamentous species (usually red algae such as Polysiphonia spp., Herposiphonia spp., and Ceramium spp.; blue-green algae (cyanobacteria); diatoms; brown algae; green algae; and coralline algae) and detritus and sediments.
https://repository.si.edu/bitstream/handle/10088/21635/SCMS39_Lang_17.pdf
Just how bad is "turf algae" & it's effects on coral reefs ?
Introduction to Turf Algae
Algal Turfs:
Ecological Importance
"¢ Algal turfs are integral to the healthy function of one of the richest habitats on earth
"“ e.g., Knowlton 2001
"¢ Rapid turnover of this organic matter forms the base of coral reef trophic structure
"“ e.g., Wanders 1976, Adey & Steneck 1985, Carpenter 1985, 1986, Klumpp et al. 1987, Klumpp & McKinnon 1989
"¢ Algal conglomerates accumulate detritus and sediments that provide raw materials for nutrient recycling "“ e.g., nitrogen fixation by filamentous cyanobacteria
"¢ Heterogeneous microhabitats for other unicellular algae (such as diatoms), protozoans and micro invertebrates
"¢ In intertidal regions, turf communities can temper environmental stressors by retaining water and providing shade among densely packed filaments "“ Hunt & Denny. 2008.
"¢ Benefit of shading has been shown to be advantageous to some corals which resist bleaching when inhabited by endolithic algae "“ Shashar et al. 1997
"¢ Some corals recover from bleaching episodes (loss of zooxanthellae) better when green‐algal derived photo-assimilates are incorporated into coral tissue6 "“ Fine & Loya 2002
https://www.stri.si.edu/sites/taxonomy_training/Docs/phycology_docs/4_1_Introduction_Turf_Algae.pdf
Your link doesn't go to any specific page that states what you supposedly quoted. Can you please include the correct link?
&
Competitive interactions between corals and turf algae depend on coral colony form
Abstract
Turf algae are becoming more abundant on coral reefs worldwide, but their effects on other benthic organisms remain poorly described. To describe the general characteristics of competitive interactions between corals and turf algae, we determined the occurrence and outcomes of coral"“turf algal interactions among different coral growth forms (branching, upright, massive, encrusting, plating, and solitary) on a shallow reef in Vietnam.
In total, the amount of turf algal interaction, i.e., the proportion of the coral boundary directly bordering turf algae, was quantified for 1,276 coral colonies belonging to 27 genera and the putative outcome of each interaction was noted. The amount of turf algal interaction and the outcome of these interactions differed predictably among the six growth forms.
Encrusting corals interacted most often with turf algae, but also competed most successfully against turf algae.
The opposite was observed for branching corals, which rarely interacted with turf algae and rarely won these competitive interactions.
Including all other growth forms,
a positive relationship was found between the amount of competitive interactions with neighbouring turf algae and the percentage of such interaction won by the coral. This growth form dependent ability to
outcompete turf algae was not only observed among coral species, but also among different growth forms in morphologically plastic coral genera (Acropora, Favia, Favites, Montastrea, Montipora, Porites) illustrating the general nature of this relationship.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4867736/
The researchers in this paper also recognize the role alga play in promoting bacterial infections in corals. From the first paragraph in the introduction: "Feedback processes exacerbate the decline of coral populations as algae provide refuges for coral pathogens and algal exudates fuel bacterial sources of coral mortality" I'm curious why you left that out?
Now, what does
Dana Riddle, a true Elite hobbyist, tim, say about Algae Turf Scrubbers, & algae filtration in general, in discussions I've had with him ? Unlike you tim, Dana ran commercial coral farms, and -
Dana Riddle, quote -
"œI ran a commercial coral farm back in the '90's using ATS technology."
"œMultiple frag grow-out systems (literally thousands of SPS.) 20 coral genera (hundreds of frags, perhaps a 100 species)."
"œThis 1,500 gallon system was filtered by 3 algal turf scrubbers (totaling about 3 m2 surface area) plus protein skimming."
"œNo nuisance algae were growing."
"œThe algae we grew were true turf algae and the pads were covered with various red, green, and brown types."
Did Dana have any concerns at all with the turf algae he was growing? Yes.
Quote
"This red alga would attack some of the corals (Acropora mostly) and bore into the skeletons. It made some sort of toxin that dissolved coral tissues."
Only one species of red turf algae did Dana have any problem with.
A what is Dana's opinion on algae scrubbers, tim ? How long ago was this written? Has Dana Riddle read the current research showing how alga promote pathogenic processes in the coral holobiont?
quote
"I'm a proponent of algae scrubbers if they use the right algae and are maintained correctly."
Now that I've covered "turf algae", lets consider algae on a coral reef in general.
This is a quote from a Ron Shimek article you may find interesting, tim?
"Upon examination of the material of a coral reef it becomes apparent that corals are only one component of the life on such a reef, and although they appear large and evident, their contribution to the actual amount of living material on the reef is relatively small.
In their pioneering study of the reef at Enewetak atoll, the Odums in 1955 showed that the majority of non-bacterial biomass on a "coral" reef was actually in the form of algae. They found that various types of algae were everywhere. There were algae growing in the coral tissues, of course, as zooxanthellae, but additionally there were algae growing freely and widely across the coral reef. The algae on the surface of the reef were diverse in form, and belonged to many groups, from large green algae such as Codium, to coralline red algae, to coralline green algae, to diatoms and dinoflagellates.
In point of fact, they found enough algae on the reef to consider it far more reasonable to call such reefs algal reefs instead of coral reefs. I wonder how many aquarists would be hobbyists today if these biogenic structures were named after their most abundant life forms and called "algal reefs" rather than coral reefs.
In addition to the algae growing visibly on the surface of the rocks, the Odums were surprised to find that algae were growing INSIDE of all the substrates on a reef. Algae, primarily filamentous green algae, lived inside of coral heads, inside of dead coral skeleton, and inside of all coral rock and rubble. In fact, on an old coral atoll such as Enewetak where all evidence of the volcano that gave the reef its start has vanished with subsidence (the volcanic basis for the reef at Enewetak is found under some 5,000 feet (1515 m) of coral reef deposited over several million of years coral growth), virtually all of the rocks are riddled with algae and contain a lot of algal growth and biomass.
The Odums found that in the average coral head, in the region of the polyps, the density of the algal component was about 0.004 grams/cm3 and the animal component was about 0.021 g/cm3, while among the bases of the polyps the filamentous algae had a density of about 0.022 g/cm3. Below the polyp zone of the coral head the algae had a density of 0.037 g/cm3.
In other words, in a coral head with living coral tissue on it, the animal component accounted for about one-fourth of the total, 0.021 g/cm3, while the various algal components amounted for 0.063 g/cm3.
Interestingly, as well, the filamentous algal component of a coral head had a much greater biomass (about 16 times greater) than did the zooxanthellae in the coral.
The algae in the coral heads do not die when the coral animal does, and the amount of the coral algae in various rock components of the reef is shown in Figure 1. This figure, modified from the Odums' 1955 paper, shows the relative biomass of several rocky areas on the reef. I have colored the algal biomass amounts green, and the biomass inside rock that could be collected as live rock in yellow. The amount of algae living inside the various components of coral rubble and rock is quite significant, and those algae are quite important to our discussion of live rock porosity. If corals are grown in environments free of the algae that colonize their skeletons, those skeletons are typically quite porous. However, the algae growing within the rock add to the porosity by dissolving fine holes for their filaments."
.
http://reefkeeping.com/issues/2004-0...ture/index.php
Yup. Science has moved on though and you haven't posted anything that shows the labile DOC from alga does not promote pathogenic processes on corals .
:lolspin: :lolspin: :lolspin:
Triton Base elements CORE 7, (o) four channel peristaltic pump, (p) multi chamber container for individual element corrective dosing, 
