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View Full Version : How to feed your Reef tank so your corals can grow Part 1 & 2



robalv
Sun, 23rd May 2010, 11:09 AM
I found this article on Reef Central thought it would be helpful.... and no Karin I am not the author.....http://reefcentral.com/forums/showthread.php?t=1843241

How to FEED your reef tank so that your corals will really GROW, instead of ho-hum...
With my fascination of reefs from watching tv, I have since been doing a ton of research (I knew I went to school for something!) on how to eventually have a nice reef tank. While I don't have the money to set it up yet, I do have the time to research how things actually work, and what will be needed for it. Lucky for me, a college buddy of mine was studying marine biology, and we have kept in touch ever since. He is now working with a group that is doing advanced research on coral reefs, and he was nice enough to give me some coral feeding info that they are putting together for hobbyists. He said I could post the info if I wanted, as it gets written. He also said they are trying to simplify it, to make it easier for us to understand (no complex numbers, references, researchers, etc.) So here is the first part... hopefully it will help you feed your corals, and mine too when I get some:

WHAT HAPPENS TO MOST CORALS: Reef aquariums are probably the most amazing thing you can have in your living room, and they really impress almost anybody, even if the tanks have only fake plastic corals. But reef tanks owners themselves are only impressed if they are successfully keeping real corals, which means of course, that the corals are not dying. Further, reef tank owners are even happier when their corals are actually growing and getting larger. The happiest moment for some hobbyists is when their corals are reproducing and showing up in new spots all over the aquarium where they never were before, just like corals do in the ocean.

In the real world of reef tanks, however, many corals die, or get covered with algae; they don't grow much (compared to the ocean), and hardly ever reproduce in remote spots in the aquarium (except for mushrooms, etc). If the corals grew like they did in the ocean, a three year old reef tank, started with only frags, would be packed to the glass and sticking out of the top from just the growth and reproduction of those original frags. Some hobbyists do know how to grow some corals, but they do so with lots of experience and equipment. No hobbyist, however, has been able to keep all coral types alive, much less keep them all growing and reproducing. So this info is designed to show you why this is, and maybe for the first time, to change it for the better.

CORALS NEED FOOD: If I were to tell you that I just bought a fish that lives on sunlight alone, and does not need food, you might be disappointed that someone lied to me at the fish store. But this is how many reef hobbyists think about their corals; they think that corals live on light alone, and that the corals do not need feeding. This is exactly the opposite of how it really works, and is the reason that their corals do not reproduce, grow, or even stay alive in some cases. In the ocean, there are no (zero) corals that live on sunlight alone. There are, however, corals that live on food alone, and which don't require sunlight. So, what exactly is this food that corals eat?

Corals eat PLANKTON. And the more plankton that is flowing in the water, the more that ALL the corals will grow. This is not the case with light: Corals need various amounts of light, but they will not grow more if the light increases past a certain point. With plankton, however, there really is no limit to the growth. Corals grow faster in the ocean when there is more plankton, and they grow slower when there is less. But most hobbyists have very little plankton in their tanks, if any at all, so sometimes the best they can hope for is that it's enough to keep the corals alive. Some hobbyists will mess around with the lighting, thinking it is the cause of slow growth, when actually it is just the lack of food.

WHAT PLANKTON IS: Plankton is the stuff that floats in the water. It's the stuff that looks like dust or dirt, or like little bits of trash. The bits can sometimes be so small you can't see them, or they can be as large as a pinhead. And they can be either alive or dead. The important part is, they FEED your corals. Yes, corals eat both the living AND the dead stuff that floats in the water. Here are some details on the types of plankton:

Zooplankton: These are little living animals, mostly little pods. Just remember "zoo", as in animals at the zoo. In the ocean, most of the zooplankton is copepods, which are as small as a grain of dust, or as big as the point of a pencil. Other zooplankton are rotifers and mysis. Ocean reefs are packed with zooplankton. Zooplankton is the major food of corals, and many small fish too (many baby fish eat only zooplankton).

Phytoplankton: Phyto mean "plant", and these tiny things are microscopic bits of plants that float around the top part of the ocean (about 300 feet deep, across 70 percent of the earth). They are actually algae, and they are the most important living things on the planet. They are 90 percent of all living life in the ocean (besides bacteria); they feed everything in the ocean, and they produce all the oxygen that you breath. Without phytoplankton, everything on earth would die (except maybe bacteria). Phytoplankton are so small that you cannot see even billions of them. Matter of fact, the crystal clear reefs that you think are "pure", are actually loaded with huge concentrations of phytoplankton in the water.

Detritus: Pronounced similar to "just-TRY-us". Detritus is stuff that used to be alive (zoo, phyto, fish waste, coral waste), but now is dead. Reefs have more detritus floating around than any other part of the ocean, so detritus is a major food for corals.

Bacteria: The number one life form on Earth, including in the ocean. Bacteria is very active on ocean reefs, and it feeds lots of corals, although not as much as zooplankton.

HOW FAST DO CORALS GROW IN THE OCEAN: Fast-growing branching corals, like staghorn acropora, can grow 8 to 10 inches (20 to 25 cm) per year in length. Here is a sample report:

robalv
Sun, 23rd May 2010, 11:10 AM
Part 2....

Geoscience Research Institute
http://www.grisda.org/origins/06088.htm

"Most polyps at 66 cm from the tip will be approximately 7 yr older than polyps at 3 cm from the tip" [this equates to a linear growth of 9 cm per year; a frag that is small today would be 18 cm in diameter (7 inches) in one year.]

"Sewell (1935) reported 280 mm/year [11 inches] in the Andaman Islands in the Bay of Bengal, and Verstelle (1932) reported a maximum rate of growth of 414 mm/year [16 inches] in the Celebes."

"The fastest growth rate reported for any coral is the staghorn species Acropora cervicornis. Lewis (1968) found in Jamaica a maximum rate of 264 mm/year [10 inches]. Shinn (1976) studied the growth of this species following destruction in a hurricane near Florida. He estimated linear growth rates of 100 mm/year [4 inches]. He also found that because of the branching habit (several new branches added to a single previous one), much more than the linear growth of a single branch is involved in establishing a dense stand of this coral. Under these branching growth conditions, carbonate production [growth] would be more geometric than linear, and could contribute further to the carbonate mass [size] of the reef. Gladfelter, Monahan and Gladfelter (1978) report rates of 99 mm/year [4 inches] for Acropora palmata in the Virgin Islands."

And here is another study:

Growth Of Acropora Pulchra in Bolinao, Pangasinan, Philippines. Proceedings of the Fourth International Coral Reef Symposium, 1981:

"If mean monthly growth rates for all [test] sites are averaged, they can be extrapolated to obtain a mean annual growth rate of 18.1 cm/year [7 inches] for Acropora pulchra. 22.58 cm/year [9 inches] was obtained for the same species at Yap Island in the Western Pacific, in a study that covered only the cooler [slower growing] months of October to December."

Mean growth rates of Acropora pulchra control colonies:

Date -- Mean Growth Rate (cm/month)

10/80-12/80 Site A: 1.8 Site B: 1.6 Site D: -
12/80-01/81 Site A: 2.3 Site B: 2.0 Site D: 1.5
02/81-04/81 Site A: 1.4 Site B: 1.3 Site D: 1.2
04/81-05/81 Site A: 0.6 Site B: 0.8 Site D: 0.6


HOW TO FEED YOUR CORALS: To achieve growth like in the ocean, corals need to be fed like they are in the ocean. Most all corals do use sunlight, and this is called Autotrophic feeding. Auto means "self", and Trophic means "feeding". Sure enough, the corals use the sunlight to "make" some energy for themselves. Most all aquariums have enough light, especially reef tanks, so fortunately this is not a problem. Most of the energy from sunlight, however, is only used to keep the corals alive; very little is used for growth and reproduction, which is what we want.

The second type of feeding is call Heterotrophic. Hetero mean "different", and sure enough, corals also eat food that they don't make themselves. Matter of fact, this is how corals get most of their food, especially when it comes to growth and reproduction. This food can be any of the plankton listed above: Zooplankton, phytoplankton, detritus, and bacteria. It's the zooplankton that does most of the feeding; and since zooplankton is actually alive, the corals are said to be "predators" of the zooplankton. It's kind of weird to think of corals as predators, but if you ever get a chance to use a microscope to watch coral polyps (especially SPS) use their chemicals to zap and eat pods, you'll understand. A polyp senses a pod (some polyps actually chase pods), and then it stings the pod with chemicals; it then wraps around it with a sticky net and pulls the pod into the "stomach" of the coral where the pod gets digested over the next couple of hours.

This digestion part is important, because a polyp cannot eat again until the initial food is digested. This is why you want to supply food to corals 24 hours a day, especially at night, which is when most feeding occurs in the ocean. If you just try to target-feed your corals by blasting them with (any kind of) food, only the first few particles that hit the coral will get eaten and digested, and all the rest will go to waste. So if you are going to limit coral feeding to certain times, make sure it's at night, or else the polyps won't catch enough. But by far the best technique is 24 hours a day, just like they eat in the ocean.

SUMMARY: With some slight changes in your feeding techniques, you can multiply the growth of your corals many many times, and even get them to multiply/reproduce in remote parts of the aquarium where they never were before. And maybe you can also help save corals from extinction, starting with the Acropora cervicornis "Staghorn Coral", and the Acropora palmata "Elkhorn coral", which are already almost gone (95 percent extinct, due to environmental changes) and are not expected to be around much longer in the ocean.

Lastly, here are two plankton videos that we found on youtube, which do a pretty good job of describing what plankton is:

http://www.youtube.com/watch?v=LuXMz3j9E8k
http://www.youtube.com/watch?v=A9AKf6OnuPg

Europhyllia
Sun, 23rd May 2010, 11:55 AM
Interesting article. Thanks for sharing Rob. It makes a lot of sense.
I turn off the return pump for a few hours when I dose phyto but don't really have a 24-hour system. Any suggestions how to provide nutrient input round the clock?

StevenSeas
Sun, 23rd May 2010, 12:05 PM
i missed the meeting was working :( was there anything in Ace's speil about how to culture live food for coral? would it be applicable to input this to a tank environment/setting?

robalv
Sun, 23rd May 2010, 12:28 PM
Interesting article. Thanks for sharing Rob. It makes a lot of sense.
I turn off the return pump for a few hours when I dose phyto but don't really have a 24-hour system. Any suggestions how to provide nutrient input round the clock?

Here is an link I found The Reef at Night....
http://seacamel.livingoceansfoundation.org/index.php?option=com_content&view=article&id=22&Itemid=72

As far as a 24 hr system on your tank I think you may have to provide it every 12 hrs....?

robalv
Sun, 23rd May 2010, 12:29 PM
i missed the meeting was working :( was there anything in Ace's speil about how to culture live food for coral? would it be applicable to input this to a tank environment/setting?

Didn't make the meeting....sorry

tebstan
Sun, 23rd May 2010, 01:23 PM
Cool. Thanks for posting.

I like the SF Bay Plankton vid

I want to see this:


. . . since zooplankton is actually alive, the corals are said to be "predators" of the zooplankton. It's kind of weird to think of corals as predators, but if you ever get a chance to use a microscope to watch coral polyps (especially SPS) use their chemicals to zap and eat pods, you'll understand. A polyp senses a pod (some polyps actually chase pods), and then it stings the pod with chemicals; it then wraps around it with a sticky net and pulls the pod into the "stomach" of the coral where the pod gets digested over the next couple of hours.

robalv
Sun, 23rd May 2010, 01:36 PM
Cool. Thanks for posting.

I like the SF Bay Plankton vid

I want to see this:



You are Very Welcome

Ping
Sat, 29th May 2010, 08:28 AM
Most aquarium corals die due to the stress from transportation or poor water quality. Now that most systems have enough live rock and refugiums, sufficient plankton usually exists in the system to feed the corals when enough random current is present. If you ask long term aquarist’ what they feed their corals, the preponderance will reply…fish poop. Feed the fish and the system should do the rest, no marketed coral food is required for photosynthetic corals in most systems.

Notes:
Phytoplankton farming requires fertilizer – if we put it in, the excess or waste must be removed.

If Phyto is added, it should be dosed to a refugium that can be shut off from the main system for a few hours. This will give the plankton time to consume the Phyto.

MH lighting does not even come close to providing the energy natural sunlight provides corals at the latitudes the coral we keep come from.

Long term health of our systems can be aided with the bi-annual addition of a small piece of freshly cured live rock, annually exchanging of a cup of sand from an established system, occasionally exchanging algae from a fellow aquarist, and a yearly rearrangement of some of the live rock.

Water changes, water changes, water changes.

Ping
Sat, 29th May 2010, 08:43 AM
Another huge problem with reef aquarist’ is adding sensitive higher life forms too soon and too fast. A six month old tank is only just beginning to become stable. Things look great for awhile, then a large algae bloom or a partial to full coral crash.

allan
Sat, 29th May 2010, 07:28 PM
Pete, Really good to see you chiming in! ;)

After reading the articles and Pete' comments I'm tempted to turn off the uv sterilizer. It is after all the fuge that feeds the dt as well as filtering for the dt.

Ping
Sat, 29th May 2010, 08:42 PM
I am one of those who feel a U.V. unit makes for a healthier tank. It should be run as a stand alone unit. Pumped from the sump into the unit and back into the sump.

Europhyllia
Sat, 29th May 2010, 08:59 PM
won't it kill anything that goes through it (including beneficial stuff)?

Ping
Sat, 29th May 2010, 09:21 PM
yes, it kills most of the life forms that pass through it if the flow is slow enough. They do raise the ORP and lower the PPM of pathogens in the water column. The dead items will be consumed by the systems inhabitants.

I have found that running a U.V. eliminates many ICH outbreaks.

kkiel02
Sun, 30th May 2010, 12:36 PM
I am going to give UV a shot when I transfer everything to the new tank. I plan on running it in the sump like you mentioned though. This is just another reason everyone should have a fuge- Pretty much free fish and coral food.

Europhyllia
Sun, 30th May 2010, 01:48 PM
I have a UV sterilizer but have only ever used it on my quarantine tank.
After reading the above I tried to find some more info on it.
Here's an article by Steven Pro that I found kind of interesting:
http://www.reefkeeping.com/issues/2003-10/sp/feature/index.php
and from it:

Treatment Option 9: U.V. Sterilization
Ultraviolet sterilizers work by damaging most anything in the water column that passes through them. Their effectiveness is dependent on the wattage of the unit, the flow rate through the unit, the age of the lamp, the volume of the water being treated, the cleanliness of the sleeve, the clarity of the water, and the decorations (potential hiding spots for tomonts) in the aquarium (Moe, 1989). Colorni & Burgess (1997) discuss the use of UV. They extrapolate from a previous study done on freshwater Ich, Ichthyophthirius multifiliis, and UV (If you are so interested, the original article is Gratzek, Gilbert, Lohr, Shotts, and Brown's 1983 piece "Ultraviolet light control of Ichthyophthirius multifiliis in a closed fish culture recirculation system." It can be found in the Journal of Fish Diseases volume 6 pages 145-153). In the study, they showed UV could prevent the spread of Ichthyophthirius multifiliis when used on a central system, but could not affect a cure within an individual aquarium. Colorni and Burgess believe the same would hold true with Cryptocaryon irritans. I would concur with them as my own personal/professional experience has demonstrated the same. I have found UV's to be very effective in bare bottom tanks, primarily in retail and wholesale operations. In display aquaria, the volume of the tank, the substrate and rockwork, the flow rate of the UV, and the wattage all work against its effectiveness. In commercial operations, many times, employees wipe down bare bottom tanks daily to maintain a clean appearance for customers. This has the added benefit of knocking loose the cyst stage of the parasite. The bare bottom, minimal decoration, high flow rates, and massive UV units on these systems ensure that most all the cysts and theronts pass through the sterilizer and are neutralized.
Please note that while I have drawn a comparison between freshwater and saltwater Ich, there is no taxonomic relationship. They may appear superficially similar to aquarists and they do in fact share some common features such as life cycle, mode of reproduction, and dispersal mechanism, but they are different and distinct organisms. This is a case of convergent evolution; when different organisms evolve to have a similar appearance because they occupy similar niches. There is a very nice example illustrating this phenomenon located at this website (http://www.waypoint1.aone.net.au/converge.htm).

nubz
Sun, 30th May 2010, 03:28 PM
very nice!!!! im gonna go feed my corals right now!!!!

dclegern
Tue, 8th Jun 2010, 10:13 PM
robalv.
Assuming the dosing of phyto and need for high nutrient content for growth.
Is turning off the skimmer at certain times a good idea?
and how about running a no-sponge/filter system(other than skimmer)?