why feed plankton?

[shahramkel]

Hi, this is probably going to sound pretty stupid, but why is it that the plankton/phytoplankton level in a normal tank is not self-sustaining? I keep reading that sps corals need to be fed, and I don't understand why plankton and phytoplankton don't reproduce enough to keep up with demand; or do they, with a properly set-up refugium?

[Telgian]

I'm not the Doc, but here's my guesses:

Removal by filtration.
Not enough water volume for an adequate supply.
Not enough species present to produce larvae.

[enitnelaVeyaF]

Plus, phytoplankton is the bottom of the food chain.

Metaphoricly, it would be like trying to maintain a terestrial biotope without plants. Plants are a key component to the food chain.
If your tank has a refugium, that will certainly help. But they are food for many many many different organisms, like zooplankton, which is hard to see in a tank. The more zooplankton, the better off the next organism in the chain will be. Basicly, adding the phytoplankton will maintain your food chain/web and strengthen it. Sure, you dont have to, most people dont, but it would certainly help the biodiversity in the tank.

And yes, many many methods, expecially skimming, will take the phytoplankton out of the water. But even if nothing manually took it out, you would still want to feed it to grow the next organisms in the chain.

[rshimek]

Originally posted by shahramkel

Hi,

Hi, this is probably going to sound pretty stupid, but why is it that the plankton/phytoplankton level in a normal tank is not self-sustaining?

Actually, darn near nothing in our systems is self sustaining. :D

I keep reading that sps corals need to be fed, and I don't understand why plankton and phytoplankton don't reproduce enough to keep up with demand; or do they, with a properly set-up refugium?

Telgian's comments about why phytoplankton are not self-sustaining are well taken. [thanks]

In addition, corals are animals - just like you. And like you, they need to be fed. On the scale of food production, a refuge tank is rather like a 10 x 20 foot garden plot planted in turnips and tomatoes. Just as you would have a hard time living for more than a few weeks on the production of only what comes out of such a small plot of ground, particularly this time of year :D, so do corals have a requirement for more than the small, itty bitty amount of food that comes out of a typical refuge tank. On regular reef, all of the corals eat various types of plankton (see the 7 part series on the food of a reef by Eric Borneman in various issues of [rk] in 2002, and 2003), but these planktonic organisms (plant, animal, algal, and bactierial) are produced by a immense body of water. It is not an exageration to figure that it takes the plankton production from several cubic miles - CUBIC MILES - of water to fuel the growth of a few linear meters of coral reef crest for a year.

The largest captive reefs (aquariums) have been on the order of 2,000,000 gallons. They do not have enough water volume to sustain a population of phytoplankton.

Finally, what is an sps coral? The name is meaningless when actually describing the animals. It is rather like using the term, "animal with fur" to describe mammals (dogs, cats, cows, and people). Each species will have its own specific requirements.

Just as you probably wouldn't survive long on eating the diet of cows, or dogs, "coral species A" will need different foods or foods in differing amounts than "coral species F."

Feeding phytoplankton (and even better :D, not all phytoplankton is created equal with regard to food value) is a way of providing some of the needed diversity in the diets of the various organisms in our tanks.

[dwdenny]

how often should you feed your corals giving the different needs of differnt species. I am setting up a Caribbean biotope in a 46 gallon bowfront. with a single 250 15k coralvue retro kit. I was planning on coral species from this area only. However I know that some will not exactly be all from this area but will do my best to keep it this way. I know the brace in the center is going to give me a shadow over the tank so I was planning a dropping ridge type of rock work where I could put most of the lower light corals like mushrooms on one side and the higher light corals like cabbage leathers on the other. Please correct me if I am wrong here in any way. I might need to add some PC lighting to the other side but I will cross that bridge when I get there ever thing is in the planning stage and hope to get things up and going by april or so. I was also planning a close loop for circulation to help cut down on powerheads in the tank. I was thinking a mag 5 would be more then enough as well a bak pak 2r or remora not sure yet. Wel that it for now any suggestions or improvements are welcome.

[rshimek]

Originally posted by dwdenny

Him

how often should you feed your corals giving the different needs of differnt species.

Ideally, you should never quit feeding your corals. They get food continuously and they are adapted to getting a lot of it.

For information on the specific types of diets and flow regimes that these animals need, you should read the following references:

Heidelberg, K. B., K. P. Sebens and J. E. Purcell. 1997. Effects of prey escape behavior and water flow on prey capture by the scleractinian coral, Meandrina meandrites. In: Lessions, H. A. and I. G. Macintyre. Eds. Proceedings of the eighth international coral reef symposium, Panama, June 24-29, 1996. Smithsonian Tropical Research Institute. Balboa, Panama. pp. 1081-1086.

Heidelberg, K. B., K. P. Sebens and J. E. Purcell. 2004. Composition and sources of near reef zooplankton on a Jamaican forereef along with implications for coral feeding. Coral Reefs. 23:263-276.

Sebens, K. P. 1997. Adaptive responses to water flow: morphology, energetics, and distributions of reef corals. In: Lessions, H. A. and I. G. Macintyre. Eds. Proceedings of the eighth international coral reef symposium, Panama, June 24-29, 1996. Smithsonian Tropical Research Institute. Balboa, Panama. 2:1053-1058.

Sebens, K. P., J. Witting and B. Helmuth. 1997. Effects of water flow and branch spacing on particle capture by the reef coral Madracis mirabilis (Duchassaing and Michelotti). Journal of Experimental Marine Biology and Ecology. 211:1-28.

Sebens, K. P., S. P. Grace, B. Helmuth, E. J. Maney Jr and J. S. Miles. 1998. Water flow and prey capture by three scleractinian corals, Madracis mirabilis, Montastrea cavernosa, and Porites porites, in a field enclosure. Marine Biology (Berlin). 131:347-360.

[shahramkel]

Thanks Ron- so it's largely a matter of not enough real estate to cover the demand. Makes sense - I guess I'll proceed with the phytoplankton and plankton reactors as planned. - Shahram

[fgarbrec]

I batch feed my tanks rotifers, nanochloropsis and artemia as often as I have the stuff, usually about every 2 to 3 days. Would it make sense to run continuous production reactors to produce a small but steady supply of plankton? Seems like it wouldn't be too difficult to do; anyone have experiance doing this?
Fred

[McBeck]

Will Purina ever come out with Reef Chow? :lol:

[shahramkel]

Sounds like a good idea. No, not the purina. I'm thinking dosing pump, but maybe that would be too rough on the plankton. Gravity fed would be ideal.

[romunov]

And cheaper. :D I'll be using coke bottles + I/V kits you get at doc's or at the veterinary.

[orion76]

Originally posted by shahramkel
Sounds like a good idea. No, not the purina. I'm thinking dosing pump, but maybe that would be too rough on the plankton. Gravity fed would be ideal.

I don't think that matters, especially if it's about to be fed.

[rshimek]

Hi,

It won't be rough on the plankton at all. They are generally too small in relationship to the pump parts (consider, sorta like flies going through a revolving door). :D

[romunov]

Found an interesting link if any one is interested...
http://192.171.163.165/pil/plankton_image_database_homepage.htm

[shahramkel]

Hmmm... tasty. Good to know the pump won't bother plankton, always worried about that.

[rshimek]

Hi,

Larger planktonic animals can be blenderized, but the small things, such as phytoplankton and most small zooplankters just too small to be bothered. :thumbsup: