Article on Phytoplankton

[Mando77]

I wanted to share this article I read and get some opinions because I have not heard anything like this before. Is there a benefit to using phytoplanton?

 

Phytoplankton - What Your LFS Isn't Telling You

 

Ah, the green stuff. The miracle cure, the lifeblood of a reeftank, the savior of fan worms and clams of all ages... Or maybe not so much. Could it be that phytoplankton actually does more harm than good in a reef aquarium?

 

In the ocean there is a lot of phytoplankton and it's crucial to the ecosystem. In the ocean. In your tank, however, phytoplankton dies and fouls up your water quality. I mean let's think about it, you're pouring live green stuff into your tank where chances are that only a miniscule part of it will be used for food. In fact, it is arguable if any realistic part of it will be used for food by your tank's inhabitants.

 

To lay to rest some of the myths: fanworms do not need phytoplankton, neither do pods, tubeworms, your rock, or clams. Or anything. It's quite possible, and by quite possible I might mean a 100% certainty (refer to disclaimer below), that nothing at all in your tank will notice the difference as to whether phytoplankton is present or not. In my system I haven't been using phytoplankton from day one, and I have walls of fanworms and tubeworms, tons of pods and mysid shrimp to the point that even my morbidly obese mandarins can't seem to eat enough to make a dent, and very tiny 1" maxima clams that grow 1/8-1/4" every few weeks with light alone.

 

There have been some questionable studies done, funded in part by phytoplankton growing companies, that make it seem like all small clams need phytoplankton to survive, and these studies are based on the fact that small clams (under 2") will consume phytoplankton for energy whereas larger clams tend not to. While it is true that phytoplankton is beneficial to some extent for very small clams, it has been shown that it is not essential for keeping small clams. Or any clams at all! (Editor's note: legitimate research has shown that Tridacnid spp. clams merely use the phytoplankton, as a nitrogen source and as we all know, our aquariums usually have an ample supply of nitrogenous products available!)

 

The fact of the matter is that very small clams, like any very small organism, do not adapt well to being moved, bagged, shipped, and acclimated. Unfortunately they have been appearing more and more in this hobby due to clam farms in the indo-pacific having very little supply of larger clams, and simply shipping out the juveniles at nearly the same prices.

 

Regardless, when small clams die it is often blamed on their lack of phytoplankton, which is in part erroneous since acclimation and shipping stress was the original issue. It has been shown that very small clams will do better when removed from the tank and placed in a bowl with a high amount of phytoplankton and sea water, called "target feeding", but it has also been shown that small clams will do well with light alone being that they already contain the zooxanthellae needed for photosynthetic growth. The more you read up on it, the more you'll notice that for every argument for phytoplankton there are about a dozen much better arguments for not putting it into your tank.

 

Unless you specifically plan on keeping a lot of small clams and target feeding them daily, which would be a bad idea in and of itself in my opinion, you can do without phytoplankton with no ill effects. When you go to a fish store though expect to hear that your tank will need it or it will not do well. The simple fact is that phytoplankton can and will compromise your water quality, leading to increased algae, more nutrients, slow or stopped coral growth due to increased phosphates, and definitely loss of coral color. Save your money for more productive things and don't let your LFS sell you things you don't need, this hobby's expensive enough already!

[trockafella]

Why do your posts end up in random forums.? Not saying its your fault, but every post is in the wrong section. Why?

[Brian Ward]

This feels like it's in the wrong place. Moving to General Discussion. If you wanted it in Mr. Coral's forum then let me know and I'll move it back.

[Incredible Corals]

I used Phyto about 6 months in with my first reef. I used as directed and every time I would get an algae bloom by the end of the week. I kept getting Cyno and my glass would be covered to the point were I couldn

[Brian Ward]

My take on the article:

The author has done no scientific research of his own and cites no peer-reviewed articles or studies to support his claims. While juvenile clams may do well in his tank without phytoplankton, that can be for a variety of reasons. His water may be "dirtier" than most so the addition of phytoplankton serves no purpose. He's also specifically talking about clams here and then generalizing it to the aquarium as a whole - what about non-photosynthetic corals such as sun corals or gorgonians? Phytoplankton (I believe) can also serve as a food source to synthetic corals that have bleached, allowing the hobbyist to nurse a coral back to health (don't confuse bleaching with RTN or STN. When a coral bleaches, it expels the zooxanthellae but the coral polyps remain. The coral is then not photosynthetic and will require target feeding until it reacquires a critical mass of zooxanthellae). I agree with the author that most people probably don't need to feed phytoplankton. But making a blanket statement that it's not useful in an aquarium is a bit obtuse.

[Coral Hind]

A. Byrnes, Where did the article come from?

 

I agree with the article as it relates to clams and most of the corals we keep. I tried dosing it in my reef tank and I saw no improvements. However in situations like Brian mentioned above I do see that it would be benificial as a food source to corals which may depend on it.

[Mando77]

Here is the site.

 

I get weekly emails on random stuff from them. Some of it is pretty good.

 

http://blog.captive-aquatics.com/captive_aquatics/2010/10/phytoplankton-what-your-lfs-isnt-telling-you.html?utm_source=feedblitz&utm_medium=FeedBlitzEmail&utm_content=554544&utm_campaign=Weekly_'2010-11-01%2006:15:00'

[bluce]

This contributer to WetWeb Media believes phyto has its uses

http://www.wetwebmedia.com/phytoplankton.htm See article below

I guess my opinion is that it is good with lite dosing.

 

Phytoplankton: Use in Marine Aquariums

by Sara Mavinkurve

Help , gear is definitely available

What is phytoplankton?

 

"Phytoplankton" is a term that covers a broad group of autotrophic micro-organisms. Though not usually included in the aquarist's concept of phytoplankton, diatoms and dinoflagellates are also types of phytoplankton. The types of phytoplankton commonly used in aquarium feeding products are Chaetoceros, Nannochloropsis, Tetraselmis and Isocrysis species (among others).

 

These are commonly used in aquarium feeding likely because they are easy to culture and thought to be of the approximate size best for the organisms we want to feed with them.

 

3 Sources of Phytoplankton (for aquarists):

 

1) Phytoplankton in Your Tank:

 

Some phytoplankton is actually already in your system. In fact, when you wipe your glass clean with a sponge or Magfloat, and you see green clouds of green or brown released from the glass--that's phytoplankton (along with bacteria films, pods and other coral/invert yummies).

 

2) Culturing Phytoplankton at Home:

 

Phytoplankton can also be cultured at home. In my opinion, unless you need a very "pure" (containing only one particular species of phytoplankton) culture, culturing at home is not quite as difficult or cumbersome as it's rumored to be. I've done so on a windowsill in a simple 2.5 gallon tank with an airstone. I simply used DT's to start (which is a mix of phytoplankton

species). The resulting culture was likely only one of these species (when a mix is used to start a culture, one will almost always out compete the others). My culture was also likely populated with bacterias and other microbes. But for my purposes, this was just fine (if not a good thing). All you really need to culture your own phytoplankton is a dedicated tank (or other water holding container), airstone, light source, and "food"/fertilizer for the algae. (Note: For more step-by-step instructions: Melev's article on phytoplankton culture)

 

3) Store Bought Phytoplankton:

 

There are many different types and brands of phytoplankton products sold online and aquarium stores. They differ in concentration, mix of species and the form in which they are stored/distributed (i.e. frozen, refrigerated, spray-dried, etc). Phytoplankton won't survive in the freezer, nor will it survive at room temperature. Most will not survive under refrigeration. However, there are a few species that will. The freezer is too cold. At room temperature, the algae would need light and air to survive. However, in the refrigerator, a few species of phytoplankton can go into a kind of "dormant" state, which allows them to survive with little air or light.

 

"Live" Refrigerated Phytoplankton ControversyWhen it comes to refrigerated phytoplankton products, not all are created equal. This subject is highly "controversial" in the reef aquarium hobby. Regardless, I'll dare to say that, based on my knowledge/experience, I don't believe that all are quite as entirely live as they claim to be. That's not to say that all the cells are dead. These products might all have some live cells. It's simply that some contain species that are not of those known to survive under refrigeration. I believe that, of the refrigerated phytoplankton products sold as "live," DT's phytoplankton (when properly kept and stored) is likely the highest quality (most live cells). Personally, it's the only one from which I'd try to start my own culture. That said, the other refrigerated products, which likely contain fewer live cells, are not bad and can certainly be used for many of the same applications. In fact, for some applications, they might be better. As with most aquarium products, ultimately, it's best to judge for yourself (try different products and see what works best in your system).

 

Frozen and spray-dried phytoplankton products are certainly dead phytoplankton cells. Again, that doesn't mean they are useless. For spray-dried phytoplankton, you'll want to soak the dry phytoplankton first. If you don't, it will float (and likely get sucked down an overflow). While live phytoplankton is generally better and will feed more organisms more effectively, frozen and spray-dried phytoplankton still has its uses. Chances are, at least some critters in the aquarium will eat it. It can also be used to feed/raise brine shrimp, rotifers, etc.

 

Reasons to feed phytoplankton:

 

There are a few aquarium corals which feed on phytoplankton. The most common ones are Dendronephtya and ahermatypic (lacking zooxanthelle) Gorgonians. It's quite possible/likely that other ahermatypic, azooxanthelle corals also feed on phytoplankton, but the Dendronephtya and ahermatypic (lacking zooxanthelle) Gorgonians absolutely need phytoplankton.

 

Most the corals we keep in aquariums are Hermatypic (both autotrophic and heterotrophic). This is a fancy way of saying that they both eat food and use light for photosynthesis. For the most part, these corals don't feed on phytoplankton (or, if they do, not primarily). However, phytoplankton can feed these corals indirectly by feeding the "critters" in our systems. These critters, when well fed, can continually reproduce, providing a great source of "natural" food for hermatypic corals. Feeding corals in this way is beneficial also because it provides a more constant (vs. intermittent) food supply (which is closer to how corals feed in the wild). [Note: In most cases, it's best not to try to target feed your corals phytoplankton... especially if the phytoplankton is cold, concentrated store-bought product. The best way to feed phytoplankton is to either drip it in continuously or pour it into a high current area of your tank.]

 

Another argument for phytoplankton feeding is that phytoplankton feeds benthic and refugium/sump critters that help process waste. Keeping healthy populations of these organisms can help keep your tank "clean" and healthy all around.

 

Phytoplankton is also used in the culturing of zooplankton used to feed, among other things, fish larvae. [Note: For some further reading on this use of phytoplankton: The Breeder's Net by Frank Marini]

 

Arguments against phytoplankton feeding:

If unconsumed, the phytoplankton will degrade and just become another source of nitrogenous waste. This might be a concern in small systems without refugiums