Growing Phytoplankton!

Im about to start culturing again, wohoo! Anyways, I made some notes on growing phytoplankton. I hope they will be usefull for those of you who are crazy like me.

Here are the common species. I personally like nannochloropsis and tetraselmis since they are sooo easy to grow. Nannochloropsis is also a VERY good source of EPAs

Nannochloropsis oculata  5 microns (EPA rich)– rotifers, brine shrimp, soft corals, most  other filter feeders, greenwater. Lacks chlorophyll b.  Probably the easiest to culture. Salinity 0-35 ppt.  2500-8000 lumens.  68-86 degrees

 

Tetraselmis sp. 9-14 microns– rotifers, shellfish, soft corals, copepods. This algae is mobile. Salinity 20-40 ppt. 5000-10000 lumens.  68-85 degrees

 

Chaetoceros gracillis (diatom) 15 microns – clams, urchins, rotifers, cucumbers. Requires silicate addition to culture water.  Salinity 20-35 ppt. 8000-10000 lumens. 77-95 degrees.

 

Isochrysis galbana 4-8 microns (DHA rich) -  clams, cucumbers, sea hares, rotifers, greenwater, copepods, soft corals. The strain collected near Tahiti is known as T-iso and is high in DHA. Salinity 10-30 ppt. 2500-10000 lumens. 77-86 degrees.

 

 

Lighting  - most 40W fluorescent bulbs put out about 2,500 lumens. Most microalgae do best with light in the red and blue spectrum. Actinic lights actually emit light at the same frequency as what chlorophyll A absorbs. A combination of daylight (6500K) and actinic is said to be a good combination for algae growth. I haven’t tried it but am going to shortly.

 

Culture medium – For dense cultures, the culture medium and culture vessel should be contaminant free. An easy way to sterilize water is 7 minutes in the microwave or treat with chlorine. ½ ml bleach per liter of water, or 1/8 teaspoon of granular pool chlorine per 5 gallons. Dissolve in cup of warm water first and make sure all of it dissolves. If your water contains ammonia, the addition of chlorine can form chloramines. Aerate the chlorinated water for 24 hours and then add a small amount of sodium thiosulfate (sold at fish stores) to get rid of any chlorine and chloramines. Don’t add too much though or it will effect the fertilizer. Chlorine test strips may be useful. After the water is clean, add fertilizer. Most microalgaes do well with Guillard F/2 Medium (ie Micro Algae Grow). Id bet most people in this club just use tap water and fertilizer and have good success without messing with the decontamination step. From experience, my cultures stayed darker longer when I tried to keep them clean.

 

Setup- Id say the easiest setup is using 2 liter bottles as the culture vessels. Supplies you will need..

 

             Silicone airline tubing

             Rigid airline tubing

             Airpump          

             Culture vessels (ie 2 liter bottles)

            

Drill a small hole in the top of the lid of the 2 liter bottles just big enough for the rigid airline tubing to fit through. The hole should be just a little bigger than the tube so air can still flow out when air is being pumped into the water. The rigid tube should go all the way to the bottom of the bottle and have about an inch sticking out of the lid. Connect the soft silicone tubing between the air pump and the rigid tubing. Place in front of a light, but not too close or you may have heating issues. 3-6” is good in my experience. Id suggest sterilizing the water inside the culture vessel so you don’t need to worry about contamination while transferring water between vessels. That’s it!

 

Growing -  Add a small amount of starter algae and you’re set. If you add a couple cups of greenwater, your culture should be ready to harvest in about 10 days. The color should be a dark green. If your culture is still light green after that time period then you probably didn’t add enough fertilizer, have a water quality issue, or contamination. Try adding some extra fertilizer and see if it gets darker in a few days

 

Harvesting – Most people do some form of a continuous culture. Just empty about ¾ of the bottle and add new culture water. This way is very easy but cultures kept this way will eventually become contaminated and give a low yield or may even crash. A good alternative that will keep cultures going stronger longer is known as batch cultures. It is a lot more work and I think most people will not want to spend the extra time. Its basically cleaning the culture vessels after each use and keeping small inoculant cultures in small glass containers to start new cultures. Id recommend the continuous method since its so easy.

 

Are you getting some Chaeto?

I think I will only order Nannochloropsis right now because i just think its the best :)  The chaetoceros is much more difficult to grow. To be successful, you would probably need VHOs and maybe even an elcosed area where you can control the temperature (maybe by just doing 24 hr lighting). If i can find some used VHOs i'll try some. I made a post but nobody had any cheap one. Maybe i'll bump it...

Amie, the liquid fertilizer (either 2 part or 1) claims to have a shelf-life of over 2 years. I guess the vitamins become deactivated over time. I plan on using the powder from now on which has a longer shelf life. Im not sure if keeping it in the refrigerator will help. I think a cool, dark location would be good, thats what ive done in the past. Yes you can fertilize too much but I think the only bad result will be unused fertilizer when you feed your tank. I usually add a little extra to older cultures to help them along, although that may not be a good practice. If you are growing tetraselmis, high levels of fertilizer may cause them to drop out of solution. On the other hand, if you dont add enough, bacteria or a biological contaminant may outcompete the algae and your culture will turn a white/yellowish color.

What does your culture look like when it crashes? The cells generally fall to the bottom. If the temperature gets too hot, the cells may fall but still be green. In many cases the culture can adapt to the new temperature and will do well once acclimated. If the cells are still green, just give the bottle a shake.

Sun really isnt the best source unless it is filtered or not as intense (ie morning sun) because of heat. Amie, maybe you could move it to a different window or filter the sun somehow.

 

Are you sure its chaeto? Ive heard chaetoceros is pretty hard to grow without silicates.

I just get mine from FAFUSA.

Suzy, I was thinking about growing Isochrysis (maybe T-iso) since its high in DHA. Would you want some too?

BTW, what do your baby seahorses eat? I was thinking about either culturing copepods or rotifers using a mix of nannochloropsis and T-iso so it would be high in EPA and DHA.

I would love some T-iso!

I have a culture of copepods for my dwarf seahorses. The full sized fry
eat bbs. But, if I could get the copepods to grow faster, ther are much
more nutritious for the fry babies.

Man, I wish we could get chaeto! It grew so fast that I had copepods
growing like crazy!

Amie, I think Adam is going to order from FAFUSA.

But, if we could generate some interest, we might be able to get some
stuff from Andy Rhyne's buddy, Algagen Eric!

Adam, would you be interested in a really cool Rhodomonas if I can get
some?

Amie-

It is Frank Hoff's facility, http://www.florida-aqua-farms.com/

Adam

One thing that I found interesting is that the algaes high in DHA only last a couple weeks refridgerated. I think DTs actually put T-iso in thier product for a while but took it out because it didn't last (i think). Two of the algaes most used commercially for DHA enrichment are Pavlova and Isochrysis.

Suzy, have you used either one of those before to feed your copepods? Maybe a good mix would be T-iso and nannochloropsis.

The two easy algae to grow that store well in the refridgerator are Nannochloropsis and Tetraselmis.

And, I tried to get Chaeto from FAFUSA a few months back. They told me
on the phone they didn't have any...Do you know if they have it now?

Suzy, Algagen actually supplies some axenic (contaminant free) plates to www.aquaticeco.com but they are pricey $66. I would like to be able to make the agar plates at home without using an autoclave or other expensive equiptment. That way we could probably keep some of these harder cultures going for much longer. Using the plate method to isolate the algae can get rid of the majority of contaminants. It gets rid of everything but the bacteria that attach to the cell walls of the microalgae. Those require antibiotics that we probably cant get ahold of. Anyways if we could get some Rhodomonas that would be great. I just cant find much info other than that found on CCMP on how to grow it. Is the Iso culture the strain from Tahiti (T-iso)??