Calling all Isochrysis Galbana Phytoplankton culture growers! Share your tips and tricks with us please! Isochrysis galbana growing guide

[Pepper Reefer]

ISOCHRYSIS GALBANA PHYTOPLANKTON

Hello,
The goal of this thread is to consolidate information, questions and answers for people looking to culture Isochrysis galbana phytoplankton
I appreciate those that have cultured isochrysis galbana sharing their secrets and knowledge with us
In this post I will write what I have learned so far - in the hopes that any wrong information can be corrected, and ask questions too

As I understand it there is
Isochrysis galbana T-ISO (Tahitian strain) (more nutritious and common)
Isochrysis galbana CCMP1323 (use in hatcheries)
Isochrysis galbana CCMP1850 (high growth rate / larviculture uses)
Isochrysis galbana strain S-ISO (colder waters)
Where each have different ideal growing conditions
However it appears (correct me if I’m wrong) that most hobbyists are growing Isochrysis galbana Tahitian strain, or it seems that this is the strain being sold by many vendors

I know that phyto can grow under a wide range of conditions, where some people can have a neglected, forgotten, half drank 2 liter of Mr. Pibb sitting in their basement that only gets hit by a patch of sunlight twice a year during the equinox, and they are successful at growing phyto in spite of the neglect; but if you had to ‘make it a science’, of growing Isochrysis galbana with the highest probability of success and lowest likelihood of crashing..

Ideal Isochrysis galbana (Tahitian strain) growing conditions:

Temperature:
68-78 degrees [however some threads mention that theirs may have been hotter in sunlight - others mention being much colder, but maybe they had S-ISO?) In general consensus seems to approve of room temperature for isochrysis galbana, that a heater is not necessary for success

Salinity:
35ppt 1.025/1.026S.G. seems to have the best success - however; the ‘official’ range is 20-35ppt - this is a very wide range, where I’ve seen some say it’s closer to 25-30ppt ~1.022 S.G. for isochrysis galbana (Tahitian), some say that slightly lower salinity is better; there doesn’t seem to be as much consensus on the ‘perfect’ salinity

Container:
Large glass jars / flasks are recommended, due to the ability to sterilize easier with boiling water, but any container can work - many use 2 liter bottles, others use large tubs or tanks. Protip was to use saran wrap instead of a hard lid to avoid lid contamination and cleaning, puncture one hole for gas exchange, the other for a hard acrylic tube to reach the bottom (or you can suction cup a soft airline tube in place at the bottom)
1-2 bubbles per second, not a roaring boil - just enough to keep the container moving [do not use airstone or will froth up]

Sterilization:
It appears that sterilization is extremely important for successful culture of isochrysis galbana compared to other commonly cultured phytoplankton - failure of sterilization seems to be the leading cause of iso culture crashes. You can either add boiling water to the container, pour it out, let it air dry; or you can add water + bleach and then use a bleach removing agent after. Any piece of equipment that touches the culture should be sterilized - bacteria/copepods/rotifers/other phyto species are all potential contaminants that can crash a culture of isochrysis galbana.
Consensus is to never use tank water or ocean water due to contaminants; to use freshly mixed salt water only for an isochrysis galbana culture. Many recommend to mix fresh saltwater, then boil the saltwater for 15 minutes to sterilize it, before adding it to the culture vessel (though this is ‘optional’) if boiling, to make the water slightly more diluted to account for the water that evaporates
It appears also that sometimes it may not be a failure of sterilization on your end, that it could be that the sample bought from various vendors may not be viable due to contamination on their end, and to try different vendors if one keeps crashing.

Nutrients:
What is needed 100% of the time is Guillard F/2 formula
Isochrysis galbana can benefit from supplements of the following, or can risk depleting these and crashing:

1. Silica
2. Iron
3. Manganese
4. Zinc
5. Cobalt for B12 synthesis
6. Amino acids
7. B12 + other vitamins
8. Detectable nitrates / phosphates (ranges I’ve seen are 5ppm nitrate 0.1ppm phosphate)
9. Seaweed extract for auxins/cytokinins etc

Ideal pH: 7.8-8.2

Lighting: 5000-6500K — cheap lights work fine; supposedly an adjustable LED light strip which you wrap around the container works well; any grow light, or light in this spectrum should work fine
Consensus seems to be that isochrysis galbana requires moderate to high lighting, ~200 PAR — in general requires more light than other phytoplankton species
However too much light can lead to photoinhibition / bleaching, and crashes

Ratio of start culture to seawater in vessel for a new culture:
It seems that isochrysis galbana is better to use 1-5% ratio, where if you had a 1 liter container of saltwater, to only place 10-50mL of isochrysis galbana, and allow it to grow and not start off very concentrated; this seems to differ from other phytoplankton species, where the starting ratio is much higher.

Misc:
On average, it should be harvested 50% taken out, 50% remaining, replace with sterile saltwater, every 7 days
It appears that isochrysis galbana can struggle to restart a culture if it has been placed in the freezer / refrigerator for any period - compared to other phytoplankton, where you can keep a reserve in the refrigerator to start up a culture if it crashes, isochrysis galbana does not work very well in this way to restart a culture if it has been chilled.


Questions:
Is there anything I’ve gotten wrong about culturing isochrysis galbana (Tahitian strain)?
What do you wish you had known at the start when you began culturing isochrysis galbana?
What has been the leading cause of crashes of isochrysis galbana cultures for you?
What change to your technique(s) led you to the greatest success?


Thank you very much for making it to the end of this long post!
I hope that you reefers out there successfully growing isochrysis galbana can share your tips and tricks here :^)
If you know anyone in the community who grows isochrysis galbana phytoplankton, please tag them here!

 

[Stephers]

Hey Stephen’s,

I wasn’t able to find a ton of information on it as to why the t-iso turns green, but from what I found the researchers stated that it was either salinity or an imbalance of trace elements within the source water used to make the F2 fertilizer or the source culture water (my guess is an overload of iron or some form of trace metal because those are usually the suspects for “greening” in a reef tank).


Before I go further though, are you certain it’s still a pure strain? T-iso and nannochloropsis cells look very similar to one another. Typically even a drop of nanno being introduced into a t-iso culture is usually the beginning of the end for the culture because eventually the nanno will catch up population wise to the iso, and sometimes it will take months for people to notice the color change.

If you’re certain it’s a pure strain, then, a couple of questions:

What brand of f2 fertilizer are you using?

Are you using rodi I water as your source for making the culture water, and, are you sterilizing the culture water before use?

Whatever salt you are using to make the culture water, try and find out if it is high in iron or any other trace metals (I personally use reef crystals / Red Sea pro in a 75/25 ratio).

Also, during your time culturing, did your t-iso culture ever get to a nice dark brown color before you split the culture, or did you get it to a strong tea color then split (I’d always recommend getting your culture to a nice dark brown color at least a couple of times a year because from what I’ve read the lipid content of the iso increases once it has reached a high population density and turns a dark brown color (it slows down in growth then and begins fattening up apparently).

Thanks so much for responding.
I'm pretty certain it's a pure culture. Pretty much all of the cells are moving. I've checked the culture several times since it started turning green, because I was certain it was contaminated, and I've never seen anything that looks out of sorts, but I'll attach a video of it from today and you let me know if you think differently.

I'm using Mercer of Montana F2.

I'm using RODI and I'm sterilizing with bleach and then dechlorinating with sodium thiosulfate.

Salt, I'm using the regular Instant Ocean (purple bag). I do 1.024 sg.

I always let it get very dark before harvesting. In fact, it still gets very dark now. It's just not much of a brown color anymore.

Do you think too much light could do it? Too much light turns porphyridium green, which I had porphyridium going for a bit and I did accidentally turn it green within a week... I didn't know my lights were so strong. I gave porphyridium up, but mostly because I hated how chunky it was.

 

[RSNJReef]

Thanks so much for responding.
I'm pretty certain it's a pure culture. Pretty much all of the cells are moving. I've checked the culture several times since it started turning green, because I was certain it was contaminated, and I've never seen anything that looks out of sorts, but I'll attach a video of it from today and you let me know if you think differently.

I'm using Mercer of Montana F2.

I'm using RODI and I'm sterilizing with bleach and then dechlorinating with sodium thiosulfate.

Salt, I'm using the regular Instant Ocean (purple bag). I do 1.024 sg.

I always let it get very dark before harvesting. In fact, it still gets very dark now. It's just not much of a brown color anymore.

Do you think too much light could do it? Too much light turns porphyridium green, which I had porphyridium going for a bit and I did accidentally turn it green within a week... I didn't know my lights were so strong. I gave porphyridium up, but mostly because I hated how chunky it was.

It is very possible with the light, what kids of light is it? And how many watts?

For reference everything else you’re doing is pretty much the same thing I do except for the salt, but don’t think io is the issue.

 

[Stephers]

It is very possible with the light, what kids of light is it? And how many watts?

For reference everything else you’re doing is pretty much the same thing I do except for the salt, but don’t think io is the issue.

I'm using 6500k strip LEDs around the container. I can't find anywhere that lists the watts.... but from what I could gather, I'm guessing it's getting about 40 watts, give or take. It's the same exact lighting I have on my Tetra and nanno, which are both doing fine.

It's not SO green. Next to the tetra, it's an obvious more yellow color, especially right after harvest, but definitely as it darkens, it doesn't have that nice brown color it used to have, just more of a dirty yellow-green color.

 

[RSNJReef]

I'm using 6500k strip LEDs around the container. I can't find anywhere that lists the watts.... but from what I could gather, I'm guessing it's getting about 40 watts, give or take. It's the same exact lighting I have on my Tetra and nanno, which are both doing fine.

It's not SO green. Next to the tetra, it's an obvious more yellow color, especially right after harvest, but definitely as it darkens, it doesn't have that nice brown color it used to have, just more of a dirty yellow-green color.

What are you using for lids for your containers? When you harvest, is there any moisture or droplet buildup on the lid? If so, what color is it? I are the droplets greener than your culture?

 

[Stephers]

What are you using for lids for your containers? When you harvest, is there any moisture or droplet buildup on the lid? If so, what color is it? I are the droplets greener than your culture?

Thanks for trying to help. I discovered that the bottom half of my LEDs were not working. I have no idea how long it was like that, but now a week later, the culture is pretty yellow. So I guess perhaps lack of light did it. We'll see where it goes from here.

 

[RSNJReef]

Thanks for trying to help. I discovered that the bottom half of my LEDs were not working. I have no idea how long it was like that, but now a week later, the culture is pretty yellow. So I guess perhaps lack of light did it. We'll see where it goes from here.

Awesome news Steohens, glad to hear it recovered. It’s interesting that the lower light seemed to make it get the green hints to it. Guess that proves the original theory of light affecting its color.

 

[Littlesquishy]

If the culture turned white, is it salvageable if you reduce the light intensity or should I start over?

 

[RSNJReef]

White still has a chance. I’ve had a culture go from brown to yellow to white to nearly clear and come back quite a few years ago. Try and transfer a partial amount of the culture into a new sterile culture vessel (try not to move any particulates in the water over to the new vessel, if need be, turn off all aeration and let the culture site for 2 hours to let the particulate settle, the. Transfer the culture water from the top), then put more f2 fertilizer and put it under low light for a couple of weeks (just leave it alone), and it can come back. Not a 100% chance of it coming back but there’s a chance it can.