TABLE OF CONTENT

What are Plankton Light and Plankton Reactors?

Getting Nutrients in the Water

Microalgaes and Zooplanktons

Growing Process in Both Reactors

Brief Introduction to Zooxanthellae

Setting up the Reactors

Conditions for Proper Operation

More on Microalgae Production

Marine Phytoplankton E.S.V.

Micro Algae Disk TM and Micro Algae Grow TM

Ferreal

Rotifers and Artemia Brine Shrimp Eggs

Plancto and Marine Snow (and Summary)

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What are Plankton Light and Plankton Reactors?

Above is a picture from Aqua Medic catalogue. The picture shows the completely set up Plankton Light Reactor (the big unit) and a Plankton Reactor (the small unit in the background).

On this page, we would like to introduce to you two pieces of equipment that we have not talked about so far. Although they seem to be the same product, a Plankton Light Reactor produces microalgaes, commonly known as "Greenwater" or Phytoplankton and a Plankton Reactor produces zooplanktons instead. Hence, they can be used individually depending on what you want, or they can be used together to provide a complete food cycle. As compared to other products such as protein skimmers and biological filters, the Plankton reactors are quite different devices. When you are setting up the reactors for the first time, there are specific steps that you must take in order to start the operation properly. Unlike the other products, you harvest on a daily basis. Furthermore, keeping the reactors clean at all times is very important in maintaining the efficiency of the devices. Since there are a number of related products that you should get familiar with before using the reactors, we will spend some time on the related products as well.

So what are Planktons? If you recall from previous pages, we said that Plankton is a family of organisms that float in the aquarium and simply follow the stream of the current in the tank. We also said that Brine Shrimp is a member of the Plankton family. However, as we will explain later that Plankton is not only necessary for invertebrates, but also for corals as well.

Getting Nutrients in the Water

Saltwater Aquarists are always interested in how the creatures obtain nutrients to support their own livings. From previous articles, we know that there is hardly any nutrients, particularly nitrogenous and phosphorous compounds in the water. We also know that nutrients are generally provided by plants through the process of Photosynthesis and provided by bacteria through the decomposition of dead organisms (remember the nutrient bombs?).

As you may have guessed, when the plants produce their own foods through Photosynthesis and when the other living creatures consume the "wastes", we are automatically talking about the food chain in the tank. This is exactly what we want to achieve by using the reactors. We want to grow our own foods for the fishes, shrimps, and corals. The end product of the Plankton Light reactor is microalgaes, which can be fed directly to the invertebrates. However, you can also feed the microalgaes to Rotifiers and allow them to grow in the Plankton reactor and get zooplanktons at the end.

Microalgaes and Zooplanktons

The above paragraph has introduced a few terms that may make the whole process sound complicated. For now, let us look at how the end products fit into the entire picture. First, with the Plankton Light reactor, we have microalgaes. We said that these microalgaes can be fed directly to the invertabates. Microalgaes are actually a type of Phyto- Planktons. If you are already using Marine Phyto-Plankton E.S.V., you have been doing the same thing already. The Marine Phyto-Planktons are dried microalgaes. However, it is recommended to feed living Phyto-Planktons to Rotifers in a Plankton reactor and grow zooplanktons for the 2nd stage of the food chain. Suppose that you have both of the reactors, what you can do then is to feed the microalgaes to the Rotifers in the Plankton reactor and allow Rotifers to grow. The end result is zooplanktons, which can be fed to corals, scallops, claims, oysters, sponges, sea squirts etc. If you are using plancto and Marine Snow, you are essentially doing the same thing.

Growing Process in Both Reactors

After we have talked about the end products and what you can do with them, let us talk about how to grow them in the reactors. The first thing you need in order to grow microalgaes in a Plankton Light reactor is to have the culture. There are about 5 different types of culture you can use. The types of culture that are commonly available come in the form of a disk (at least in North America). Regardless of the type of culture you use, follow the instructions from your algae disks and get the culture ready. Inoculate the Light reactor with the culture and feed nutrients to keep microalgaes alive. By the time to harvest, you will have the microalgaes ready. Similar idea with growing zooplanktons in a Plankton reactor, you need Rotifers, the "culture" in the previous case. Feed the Rotifers with the microalgaes and let them grow. Rotifers belong to the family of zooplanktons. So to produce zooplanktons is really to let the Rotifer babies to grow. Like the microalgaes, there is a choice over the type of culture used. The other popular option besides Rotifers is Brine Shrimp eggs.

Brief Introduction to Zooxanthellae

Now we see that the ultimate goal of the system (assuming two reactors are used together) is to produce your own zooplanktons. Do the zooplanktons worth the investment? This is your decision. But before you make your decision, let us have a brief introduction to Zooxanthellae, which is another key term in the saltwater domain. Zooxanthellaes are unicellular endosymbiotic algaes that live in the tissues of invertebrates. Most of the creatures in the tanks depend on Zooxanthellaes to live.

Earlier on, when we talked about living creatures facing a great difficulty in getting nutrients from the water, we said that nature finds its own way to get around the problem. The way the creatures survive is to form a symbiotic relationship with algaes, Zooxanthellaes. Same as the other types of plants, algaes go through Photosynthesis process. In other words, they need carbon dioxide and other inorganic wastes to survive. On the other hand, fishes and other creatures need oxygen and nutrients to live. The symbiotic relationship can then be understood as the mutual relationship in which fishes and algaes provide the necessary elements for each other in order to exchange for the necessary foods for themselves. The advantage of doing this is that in the regular food chain, although foods will be provided by the other species in the tank, there is a huge amount of energy loss in each step of the food chain. The symbiotic relationship reduces the loss of energy to its minimal level. An additional benefit of Zooxanthellaes is that they help dissolving Calcium in the water in day-time (when there is Photosynthesis). If you recall from the Calcium reactor page, Calcium is a necessary element for corals to grow. But Calcium does not dissolved into the water easily. Hence, Zooxanthellaes are particularly important to the growth of corals. Therefore, it is fair to say that corals depend on Zooxanthellaes for their livings as well.

Setting up the Reactors

If you compare a Plankton Light reactor with a Plankton reactor, they certainly seem to be the same product. The only difference is an additional fluorescent light attached to the side of the Plankton Light reactor. Also with the Plankton Light reactor you need a carbon dioxide source as well. This is obvious since we are trying to grow algaes, which need light and carbon dioxide for Photosynthesis. Therefore, it is to the advantage of those who already own a carbon dioxide unit (associated with the Calcium reactor) to include a Plankton Light reactor in the entire system. (However, we do have individual carbon dioxide regulators and everything else that you will need.) Given the optium supply of light, carbon dioxide, and nutrients, the biomass of the microalgaes can increase by 4 times within a day. Plankton Reactor is a little easier to set up. With the Plankton reactor, you do not want to supply carbon dioxide since zooplanktons require oxygen to live. Under the right conditions, biomass of zooplanktons can be doubled in 4 days. In other words, a quarter of the zooplanktons can be harvested every day.

Conditions for Proper Operation

The specific operational conditions for the 2 reactors are summarized here:

For the Plankton Light Reactor:
a) suitable illumination
b) suitable nutrient supply (*See section on Ferreal)
c) carbon dioxide (*Watch the pH level as carbon dioxide lowers your pH level)
d) good water movement
e) warm termperature - between 20 to 28 oC
For the Plankton Reactor:
a) suitable nutrient supply
b) oxygen
c) good water movement
d) warm termperature - between 20 to 28 oC

More on Microalgae Production

Here is a picture of a Plankton Light Reactor unit. The brush included is for cleaning purpose. The Plankton Reactor unit is very similar, except the illumination unit.

The main components of a Plankton Light reactor are

  • Reaction vessel, with an air injection port and a check valve

  • Wall mounting plate with clamps

  • Cleaning brush

  • Illumination unit, including external ballast

At the bottom of the reaction vessel, you can hook up a T-piece to connect a check valve (connected to the air pump) and a valve for harvesting the microalgaes. There is a similar opening at the top of the vessel for the air to escape and in an automated system the opening takes a pH probe. An automated system has a complete carbon dioxide regulating system and a pH controller to control the pH level. The recommended pH level is about 7.5 for microalgaes. However, such an automated system is not required, a general rule to control the pH level in the vessel is to shut off the carbon dioxide supply at night. However, this is only a rough estimate and there is no guarantee that your reactor is working at its most efficient point anymore. Please remember that the regulation on the pH level in the vessel serves a different purpose as in a Calcium reactor. The reactor is a stand-alone unit and it is not to be connected to the tank; but the carbon dioxide content must still maintained in order to support Photosynthesis of the microalgaes. Besides the carbon dioxide unit, light should also be regulated. The light should be on for only 16 hours a day because the marginal benefit for keeping the light to be on the whole time is simply negligible. The regulation of the illumination unit is done by a timer that you can purchase in any electronic stores.

Use of Distilled Water

The Plankton Light reactor is different from the Plankton reactor in that the vessel must be filled with boiled saltwater in the first run. This is to ensure that Planktonic organisms from tap water are absent. Remember that microalgaes are food for Planktonic organisms in a Plankton reactor. Therefore, this is a necessary step if you use a Plankton Light reactor. In all future runs, saltwater used in the Plankton Light reactor must be prepared with filtered water. You can use a Reverse Osmosis unit to do this, or you can simply use distilled water from any supermarkets to mix your salt with.

After the inoculation of the culture from your algae disks, the light should be on and microalgaes (or their substitutes) must be provided in order for the culture to grow. Once the operation has begun, the green color of the culture should become stronger and a few days later, you can harvest your microalgaes. In the preparation of the saltwater, please be caution that the container you used must be perfectly clean. Failing to do this leads to zooplanktons destroying the algal culture in a few days.

Other Issues

Another issue with maintaining the operation is to keep the vessel clean. Same as any other equipments cleaning is a necessary task. If there is no Filamentous algaes bother with the operation, the old culture can be reused. If you believe that Filamentous algaes present, please consult with the manual for proper treatment.

One final comment: If you decide to use both of the vessels, please set up the Plankton Light reactor first since rotifers should be fed every day. For the details of the amount that you can harvest and the completely automated system using dosing pumps, please consult the manual.

Marine Phytoplankton E.S.V.

The Marine Phyto-Plankton mentioned earlier on comes in a form so called Spray-Dried Phyto-Plankton. There are useful guidelines that you can find in the package that explains the amount to use every time. There is a very interesting point in the guidelines. It says that the product is lack of highly unsaturated fatty acids so that the air bubbles used to skim the Phyto-Plankton are made collapsed. (We talked about the same idea when we mentioned the specific tips in using Turboflotor skimmers.) This gives a longer residence time for the Phyto-Plankton to stay in the aquarium.

Micro Algae Disk TM and Micro Algae Grow TM

Earlier on, we said that there are 5 types of culture that you can use for growing microalgaes in the Plankton Light reactor. Aqua Medic actually recommends 2 of them: Nanno Chloropsis and Dunaliella. The Micro Algae Disk TM shown here is the Nanno Chloropus. Please consult with the instruction enclosed with the Algae Disks. To feed the culture, you can add Micro Algae Grow TM. The Micro Algae Grow TM is only one of the products available; feel free to choose the type of nutrients you want.

Ferreal

Now that we know Rotiters are fed on microalgaes. What do we use to feed the culture in the Plankton Light reactor? The product that we mentioned before is Micro Alage Grow TM. However, Aqua Medic recommends Florreal and Ferreal. (As of this writing, we only have Ferreal in stock. So we will only focus on Ferreal here.) Both of the products are fertilizers. Floreal is a water plant fertilizer, whereas Ferreal is an iron fertilizer. The essential components of Ferreal are iron and molybdenum. Generally speaking, in order for algaes to grow in the reactor, algaes require ammonia. However, we know that ammonia is unwelcomed in the tanks, and hence, algaes cannot rely on the ammonia in the water to grow. Instead, algaes take nitrate and use iron and molybdenum as catalysts to reduce nitrate to ammonia. Therefore, it is recommended to use Ferreal to enhance the microalgaes' growth in the reaction vessel. Besides iron and molybydenum, Ferreal also contains trace elements like manganese, boron, zinc, and cobalt that are essential to aquatic plants.

Rotifers and Artemia Brine Shrimp Eggs


Click on the Brine Shimp Eggs picture to see another similar product - Artemia Cysts.

Rotiters, or zooplankton, are eggs that are previously obtained in controlled laboratory. Once the Rotifers are in the Plankton vessel and proper conditions are met, hatching begins in a period from one to three days. We said that Artemia Brine Shrimp Eggs are another popular choice. However, there is a difference between Rotifers and Brine Shrimp Eggs. The advantage of Rotiters over Artemia is that Rotiters begin reproducing after 18 hours since hatch and will continue to reproduce every 4 to 6 hours. Hence, Rotifers are usually recommended for the use of growing zooplanktons. (Of course, there is a limit of how much the Rotiters can reproduce!)

Plancto and Marine Snow (and Summary)

The last 2 products that we want to mention here are Plancto from Aqualine and Marine Snow from Two Little Fishies. They are similar products and generally used for plankton and invertebrates. The point that we want you to remember is that the Plankton System (Plankton Light and Plankton reactors) represents one simple thing - to grow your own zooplanktons. However, it is not a necessary piece of equipment, you can do just fine with using Marine PhytoPlankton E.S.V., Plancto, and Marine Snow.

What we want to achieve on this page is to highlight the importance of microalges, and zooplanktons. Their roles in the food chain. We have also shown a set of complete system to illustrate how to grow your own microalgaes and zooplanktons and the major issues associated with the system. If you are interested in learning more about the system, please drop by our shop for a talk.


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