Why Refrigerate Live Phytoplankton?

[Eldredge]

I have had a couple of conversations lately that made me think it might be helpful to explain why live phytoplankton should be refrigerated. This applies to live phytoplankton NOT dead phytoplankton.

The phyto species that we dose to our systems generally thrive in temperatures in the mid 70's, do well in temperatures from 70-85, and survive from 35-100. The reason for refrigerating is to slow down their metabolism and reproduction so that the culture doesn't continue to grow quickly and crash. At lower temperatures, everything is slowed down, and it will typically take weeks instead of days for the phyto to exhaust the resources available in the bottle and die.

So, if you forget to put your bottle back in the fridge right away on occasion, there is probably no harm done - might just shorten its time remaining slightly.

 

[tzabor10]

Good to know.

 

[Reef Puncher]

I have had a couple of conversations lately that made me think it might be helpful to explain why live phytoplankton should be refrigerated. This applies to live phytoplankton NOT dead phytoplankton.

The phyto species that we dose to our systems generally thrive in temperatures in the mid 70's, do well in temperatures from 70-85, and survive from 35-100. The reason for refrigerating is to slow down their metabolism and reproduction so that the culture doesn't continue to grow quickly and crash. At lower temperatures, everything is slowed down, and it will typically take weeks instead of days for the phyto to exhaust the resources available in the bottle and die.

So, if you forget to put your bottle back in the fridge right away on occasion, there is probably no harm done - might just shorten its time remaining slightly.

i know this is old, but when you say, drain the resources, what resources? is there some resource or additive we can put in a bottle to make them last longer?

 

[braaap]

i know this is old, but when you say, drain the resources, what resources? is there some resource or additive we can put in a bottle to make them last longer?

The food that is in the bottle. Be it fertilizer(that should be exhausted but isn’t always) or other organics.

No need to try and extend it. You shouldn’t keep it more than a couple weeks in the fridge anyways. It keeps losing its benefit due to die off.

I sell it. And I can keep gallons for a couple of weeks. Checking by microscope you can see the cells losing mass/density.

 

[Eldredge]

i know this is old, but when you say, drain the resources, what resources? is there some resource or additive we can put in a bottle to make them last longer?

Hello! When the phyto is harvested, there is likely a small amount of nutrients left in the culture. Once this is consumed, the phyto will crash. Some strains can survive longer than others, but if they are growing rapidly, they will all crash eventually. The cold temperatures slow them down considerably, so they don't crash for a long time.

Fresh live phyto will keep for quite a while in the fridge. The longevity may depend upon the health of the phyto at the time of harvest, and how well it is maintained during storage, but in my experience, for the first month, there really isn’t any noticeable change. During the second month, the motile cells become less active, but there is still a fair amount of activity. By the end of the third month, there isn’t really any activity, but the cells are still intact. If a new culture is started with the three-month old sample, it will grow and some of the cells will be motile. So, using the phyto within a month would be ideal, within two months is fine, and even three months is probably okay. It is best to have some air in the bottle, give it a little shake and open the lid every day.

Please let me know if you have any other questions.

 

[Reef Puncher]

Hello! When the phyto is harvested, there is likely a small amount of nutrients left in the culture. Once this is consumed, the phyto will crash. Some strains can survive longer than others, but if they are growing rapidly, they will all crash eventually. The cold temperatures slow them down considerably, so they don't crash for a long time.

Fresh live phyto will keep for quite a while in the fridge. The longevity may depend upon the health of the phyto at the time of harvest, and how well it is maintained during storage, but in my experience, for the first month, there really isn’t any noticeable change. During the second month, the motile cells become less active, but there is still a fair amount of activity. By the end of the third month, there isn’t really any activity, but the cells are still intact. If a new culture is started with the three-month old sample, it will grow and some of the cells will be motile. So, using the phyto within a month would be ideal, within two months is fine, and even three months is probably okay. It is best to have some air in the bottle, give it a little shake and open the lid every day.

Please let me know if you have any other questions.

wow thanks! another question. is there an advantage to more motile phyto in a reef aquarium?

 

[Eldredge]

wow thanks! another question. is there an advantage to more motile phyto in a reef aquarium?

That's a good question! There are some pods and other organisms that will only eat motile phyto, so if you have some of those organisms then it is definitely an advantage. My approach is to offer a variety of different nutritional profiles, cell sizes, and motility in hopes of providing food for as many different organisms as possible. Some don't care, and some have fairly strict requirements. We really aren't sure about the specific needs of many of the organisms in our systems...

 

[SinkyShippy]

That's a good question! There are some pods and other organisms that will only eat motile phyto, so if you have some of those organisms then it is definitely an advantage. My approach is to offer a variety of different nutritional profiles, cell sizes, and motility in hopes of providing food for as many different organisms as possible. Some don't care, and some have fairly strict requirements. We really aren't sure about the specific needs of many of the organisms in our systems...

Old post but if I decide to remove it from the fridge and put it into a container with a bubbler and light, can i cultivate it myself?

 

[Eldredge]

Old post but if I decide to remove it from the fridge and put it into a container with a bubbler and light, can i cultivate it myself?

Yes you can. It would probably be better to start with a single strain though. When staring with multiple strains, they will try to outcompete each other. Either one will win and you will have a single-strain culture, or the entire culture will crash. Odds are better with just starting with a single strain. I would probably go with tetraselmis. It's fairly easy to cultivate, is nutritious, and is motile.

 

[Randy Holmes-Farley Verified Community Expert]

I dose live phyto directly from a mini fridge through a hole in the bottom, straight down into my sump. There is a dosing pump and a mag stirrer also in the fridge. :)