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lduncan

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Everything posted by lduncan

  1. First, only some soft corals have the ability to gain nutrients from phytoplankton. And of those that can, it only supplies a small part of their nutrition. Most corals can't digest phytoplankton at all. Second yes, these animals could be what you call "gut loaded" however the energy the coral has to expend to get this nutrients, is much more than if it had never been consumed by these animals. Chitin is not simple to digest. Think eating a crayfish with shell. As for corals not worrying about density of nutrients, your right, as long as it provides them with more energy than they previously had. But talking efficiencies here, you have a certain amount of food in the system, doesn't it make sense to maximise the nutritional value of this food? Encasing it in a thick chitin shell at the expense of easy to digest bacterial flock is not maximising nutritional value. No the mass in that example is not constant. It's more like eating a hamburger vs. eating a certain mass of that hamburger, with the remaining mass substituted for water. There's a significant difference there. Absolutly chitin is hard to digest, as is the cellulose of algae cells. But few corals digest phytoplankton. This is the kicker, this stuff takes more energy to digest, than the bacterial food that these critters eat to begin with. They're spending more energy to get the same nutrition, so the net gain is less with these chitin encased nutrient than with bacterial detritus. Bacteria don't need this delivery system. Water flow in the aquarium can deliver them in a more nutrient packed and easy to digest form than critters ever could. Layton
  2. I quoted more than a little part of the article. I followed Dr Ron's own writings. And there was nothing in there from Eric. I've already spelt out the weird part. Here it is again: And again without the quotes: First he says that bacteria are better than pods for providing nutrients. Bigger bang for your buck. Then he says that detritus is a good food source for this bacteria to colonise, and they do so quickly, and goes on to say that sand dwelling creatures (critters) are a big competitor to corals for this nutrients. But then goes on to promote the use of sand as a great way to provide food for corals. To me that's just a weird conclusion. Using something which actually eats one of the most nutritious forms of food for corals (bacteria), and converts much of it into a form which is harder for corals to digest, while providing less nutrition. Instead of trying to come up with cock'n'ball stories of how sand beds are great for this and that, they're little copies of natural systems etc etc. Why don't people just say I use sand 'cause I like the look of it? Instead of going to all the effort of pretending it does something amazingly useful for corals? Layton
  3. Sorry that should be early 1900's above.
  4. I have. That's the one which Cookie posted earlier. The one which comes to a weird conclusion.
  5. This isn't hobby literature, it's science. Coral researchers have been able to spawn and raise acroporids in BB systems science the mid 1800's. It's just hobbyists which had problems. You have to be careful when reading that stuff to see what they actually did, and what they actually observed. Sometimes they have enough information on why, but will present possible mechanisms or reasons, but that is clearly distinct from the data. It's this which will change, not the actual data and observations. Layton
  6. Wasp, you've missed the point. Here's a summary: The amount of food in your tank is virtually determined by what you put in it. The crap which is produced by fish and corals is food for bacteria, and corals before it hits the sand. The sand provides nothing. It can't possibly produce more food than what you put in to start with. Bacteria don't require sand to grow and reproduce. The sand harbours animals which are harder for corals to digest and require more energy to digest. So, using sand to provide food food reefs is backwards, it can't possibly create more food, or more nutritious food than would otherwise exist without sand. In short sand is never going to be better than having no sand in providing coral food. Layton
  7. I didn't realise they had and expiry date Seriously, what does it matter when they were done? Surely the important part is what was done and how. Layton
  8. The Food of Reefs: http://www.reefkeeping.com/issues/2003-01/eb/index.php
  9. Borneman. Refs are: Rublee P.A., Lasker H.R., Gottfried M., Roman M.R. 1980. Production and bacterial colonization of mucus from the soft coral Briarium abestinum. Bull Mar Sci 30: 888-93 Rowher F., Breitbart M., Jara J., Azam F., Knowlton, N. 2001. Diversity of bacteria associated with the Caribbean coral Montastraea franksi. Coral Reefs 20: 85-91. Linley E.A.S., Koop K. 1986. Significance of pelagic bacteria as a trophic resource in a coral reef lagoon, One Tree Island, Great Barrier Reef. Mar Biol 92: 457-464. Herndl G.J., Velmirov B. 1985. Bacteria in the coelenteron of Anthozoa: control of coelenteric bacterial density by the coelenteric fluid. J Exp Mar Biol Ecol 93: 115-130 Herndl G.J., Velmirov, B. 1986. Microheterotrophic utilization of mucus released by the Mediterranean coral Cladocora caespitosa Mar Biol 90: 363-369. Ducklow H. W., Mitchell R. 1979. Bacterial populations and adaptations in the mucus layers on living corals. Limnol Oceanogr 24(4): 715-725. Ducklow H. W., Mitchell R. 1979. Composition of mucus released by coral reef coelenterates. Limnol Oceanogr 24(4): 706-714. Di Salvo L. H. 1969. Isolation of bacteria from the corallum of Porites lobata (Dana) and its possible significance. Amer Zool 9: 735-740.
  10. Um yeah. We've already establish that corals need food long ago.
  11. And it's something I've never denied.
  12. Food of course. I may have already posted this, dunno:
  13. Who's dodging work. I work for myself. What's to interpret? Well first none of that text is taken directly from the reference, it is what a particular manufacturer of commercial phytoplankton suppliment has to say on the matter. Anyone can write something then stick a reference in there, sometimes it pays to read the references themselves and see what they actually say ;-) I've just read the intro of one of those references. Very interesting: So with all these methods available, why the huge focus on the one which is hardest to achieve? Zooplankton. It goes on:
  14. Be patient. I'm going to call it a night soon. I'll read that reference and see if the manufacturer of the plankton products it's promoting has interpreted it very well. But there is nothing particularly new there. I wonder what they are classifying as "plankton" here. Layton
  15. Umm, yeah i've been on about the critters from the start. So what's the bingo for? It's pretty common knowledge that bacteria are more nutritious than a critter encased in chitin, with a lot of water etc. Are you saying Ron's sources are wrong? Eric say the same thing. Well you can't create mass from nowhere, pound for pound is important, as is energy expenditure to digest this stuff. There are easier sources of food for corals than critters, they are not required at all. Why does it have to be a GREAT source, maybe it's just A source? One of many possible. Layton
  16. lduncan

    tank design

    The mods surely need to bring back the edit. I guess the low iron thing only really matters when your looking at 50mm glass
  17. What do you mean bingo? You were disagreeing a second ago.
  18. Anyone here subscribe to Coral List? Here is a recent posting by Charles Delbeek, a name which is probably familiar to many.
  19. There's no free lunch.
  20. What do you mean by bingo? The critters come at the expense of bacteria. Layton
  21. Eric thinks they do, that's why they can get it from inorganic sources. That's why they actively farm bacteria in their mucus. Are you sure that's the reason corals can stop growing, lack of nutrients in our tanks. I'm not so sure. Layton
  22. But we also know that sand isn't required for this to stuff to exist. We also know that sand introduces critters into the equation, which are less nutritious, and require more expenditure of energy to digest. Not to mention the other pitfalls of sand beds. Layton
  23. Not at all, it just becomes less available, than if it never hit sand. I don't think you get it. The fact is is that by introducing large populations of critters into the equation, you are actually reducing the available food for corals, than if it is left to bacteria alone. Then why bother going to all the trouble of culturing all these critters in the first place? Why not just leave it to bacteria? I don't think you get it. What matters is what's in the water column. That where the corals can get it. Higher concentrations of food in the water column, means more food available to the corals, which also results in more stuff skimmed by the skimmer. A tank with the same skimmer and lower output means that there isn't as much food in the water for corals. That dynamic is the key. But why bother going through the critters? What's the point? When if the critters aren't there to compete for this stuff, it gets to the corals in the most nutritious form, without going through all those other processes? The sand doesn't create anymore food than what you put in. Why do you need it? Bacteria are more than capable of living without sand, and providing corals nutrition. They don't need critters, it just makes life harder for them. Layton
  24. Dr Ron told us that: And this from Eric is interesting: Layton
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