Microalgae (Phytoplankton: Rotifer / Reef Food)

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• MATERIALS
• CULTURING
• STORAGE / USAGE

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Like most other aquarists that I have spoken to, I got into messing around with Microalgae (Phytoplankton) because of necessity. When my Hippocampus Reidi seahorses suddenly spawned, I found myself with a bunch of hungry little mouths to feed and with no idea what to do. Those of us who know anything about Reidi know that their fry are notoriously small and hard to raise for the first few weeks of life. Long story short... i ended up with a bunch of rotifers and as a result, was haplessly sucked into microalgae farming.

Sure, there are lots of good quality frozen instant algae products out there on the market. Nothing can beat the convenience of frozen microalgae, but those of us who have tried to by that stuff know how expensive they can be, not to mention having a 3-6 month shelf life. When they go bad, you'll have to fork out another $$ to get new ones delivered. This is fine if you have the $$, but for the rest of us, the cheapest way to go would be to grow our own microalgae.

Besides the relatively low cost of home grown microalgae, there are a couple of benefits.

• Live microalgae can be fed directly into the aquarium for luscious coral growth and for feeding various little critters and invertebrates within a reef tank. The very fact that they are "live" and are naturally found in thier native ecosystem means that you'll have less of a chance of them fouling the water as compared to dosing the "dead" stuff. In fact, in a healthy reef environment, it may even help (temporarily) to reduce nutrients in the water column. This means that you don't have to worry too much about dosing too much in your tank. The excess will simply "live" in your tank until they get eaten. Dead stuff that doesn't get eaten... well... rots.

• Secondly, they can be used to replicate "greenwater" nurseries for notoriously small or delicate fry such as H. Reidi. The greenwater is eaten by rotifers and / or copepods and are in turn eaten by the fry. While at the same time acting as a live filter by removing nutrients from the water column. If you pour dead phyto into your fry tank... you'll know exactly what you did wrong the next day when all your fry die from ammonia poisoning.

• Thirdly, i'm convinced that live phytoplankton is the key to breeding "impossible" critters and inverts that have pelagic larvae stages such as amano shrimp, nerite snails and even mandarin dragonets. I'm still experimenting with breeding these right now and the initial results are extremely good. (Don't send me any e-mails regarding this right now... the results will be published when they get published.)

• Fourthly, they are relatively easy to culture with a relatively low time commitment. Just leave it alone and split it whenever it gets dark enough.

There are several types of live phytoplankton available to the hobbyists. Although SW microalgae being the more common, you can also grow your own FW species for feeding FW rotifers and Daphnia. The methods for growing SW and FW phyto are the same. For this article, my focus will be on a very common SW phyto "nannochloropsis", but the methods can be used to culture almost any microalgae.

Don't know what kind of microalgae you need? Reed Mariculture has a pretty nifty table to help you choose.
http://www.reed-mariculture.com/microalgae/choice.asp

MATERIALS
If you are using the same method I use, here are the things which you will need to culture your microalgae.

• Marine Salt Mix (not used for FW phyto).
• Starter culture or swab of microalgae of your choosing (Hint... try E-BAY).
• Clear plastic or glass jars with a capacity of at least 2 liters and a plastic lid (metals tend to corrode in salt water).
• Miracle Gro liquid fertilizer (the blue colored kind) + some way to measure 3 - 4 mL (perhaps a syringe or disposable pipette).
• A standard aquarium air pump.
• Rigid Airline Tubing
• Standard Airline Tubing (I like the silicone kind but that's a personal preference).
• Standard Fluorescent Shop Lamp with 5,700K bulb or close to it + automatic timer.
• Bleach for disinfecting. (Optional by HIGHLY recommended).

CULTURING

The first thing to do is to prepare the hardware. I start out with a plastic jar with a large mouth. Try to get a jar where you can stick your hand into it to clean. Some people culture in a 2L bottle with a tiny opening. Good luck trying to clean all the gunk that builds up inside over time......

Plastic Jar:

Drill a hole through the center of the lid such that when you thread the rigid tubing through it, it will be just snug (if memory serves me right, a 1/4" dia bit should do). Drill another smaller (1/8") hole into the lid somewhere closer to the edge. This second hole is to allow air to escape from the jar. Test to see that the rigid tubing goes through it ok.

Drill 1/4" hole + another 1/8" hole:

Cut a piece of rigid tubing such that it is about 1" - 2" taller than the jar itself. Connect a piece of soft tubing to one end of the tubing. Most aquarists should recognize this to be the "suck the gunk off the bottom of the fry tank" tool. But this time instead of sucking, it will be blowing (air into the jar).

Thread rigid airline into hole:

Make a mild bleach solution in a 5 gal bucket and soak the hardware (jars, lids, rigid tubing) before you start. This is to reduce the possibility of contamination from foreign algae spores which might spoil your culture.

Mix a saltwater solution to an SG which is the same as your rotifer / fry / greenwater tank. This is so that your zooplankton doesn't get osmotic shock when you pour in a bunch of phytoplankton with a wildly different S.G. I keep mine at around 1.017 - 1.019.

Assemble the hardware and connect the airline tubing to the air pump. Pour in the prepared saltwater and add some miracle gro liquid. I use about 3mL per 2L of salt water. Then inoculate your culture with the microalgae which you received.

Adjust the airflow so that you get a pretty turbulent agitation of the water. This will help to keep the microalgae in suspension and keep it from falling out of suspension.

Place in front of the fluorescent light to brew. So far I get the best results with 16hrs of light and 8 hrs of darkness. Set the timer to 16-8hrs and leave it alone. Hopefully soon you will notice the water go cloudy and then take on a green (or brown for isochrysis) tint to it. The green will intensify until eventually be opaque. Congrats! You have successfully cultured microalgae!!

My cultures:

I like to keep at least 2 jars going at the same time. This is so that if one crashes, there's backup. Also, it would be handy to have 2 more extra jars on hand when you split the culture. This is because the old jars with the phyto will undoubtedly have some nasty stuff growing on the sides which you want to eventually wash and bleach out.

the way i split the culture is that when the cultures are ready, i transfer the contents of one jar into a 2L soda bottle and store in my fridge. I split the remanding culture into two new jars and then top off with saltwater. Add 3mL of Miracle Gro to both jars and then back in front of the lamp.

STORAGE / USING

Phyto stores quite well in the refrigerator. I store mine in 2L soda bottles. I've no idea how long they keep in the fridge, but at least a week or two I imagine. But mine never lasts that long. Just remember that without movement, the phyto will fall out of suspension and settle at the bottom of the bottle. Just remember to give it a good shake once or twice a day to bring it back into suspension. Otherwise the phyto at the bottom of the bottle will compact and start dying, forming clumps.

Usage is simple... If you are feeding your reef, simply pour directly into your tank such that the water takes on a slight green tint. Feed once or twice a week for visibly healthy coral and vibrant inverts & clams.

If you have a greenwater tank / nursery or are growing rotifers, simply siphon out the water from the main tank and replace with equal parts of greenwater. This can be done when vacuuming the bottom of a fry tank or when harvesting rotifers.

Happy Phyto Pharming!

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PLUG

On the urging of my friends, I started this website by putting together the original (and quite successful) B. Macrostoma pages. Since then it has grown by quite a bit. All this time I've provided all this info and lots of free e-mail support to anyone who needed help. The advertising on this page helps out a little to offset the cost of webhosting. So if you see something that you may be interested in listed within the Google Ads banners, then please don't hesitate to check it out.

I thank you all for your great interest in my articles and I hope to keep hearing from you guys, even if it is just dropping me a note to say hi. God Bless!

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