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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. � 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 � 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.
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