Phytoplankton - when to harvest?

[Mirkus]

Quick question for all you phytoplankton experts. When do I harvest it? Most of the guides say 7-10 days. I’m only on day 5 and my culture is really dark and has been for a couple days. Im using a Amazon “150w” led grow light. I think it’s closer to 50 watts.

 

[3sgterror]

open it and smell the phyto. I have heard of them going that dark early when the culture crashes.

If the culture smells bad, then I would think it died off. If it doesn't really have a smell, I would let it go to day 7.

 

[G Santana]

The only crash I had came when the culture turned to a muddy color.
You should be fine, I let my cultures go to 10 days but I have harvested dark green cultures at 6 and 7 days.
Yours look fine and healthy.

 

[Mirkus]

open it and smell the phyto. I have heard of them going that dark early when the culture crashes.

If the culture smells bad, then I would think it died off. If it doesn't really have a smell, I would let it go to day 7.

Smells fine, it’s just really dark.

 

[Pistondog]

I would say it's done. You might want to check the phosphate or nitrate to see if the fertilizer is used up. If it is, not much point in letting it continue, right?

 

[Mirkus]

Thanks for the input all!

 

[onlyfans]

There's no set time for harvesting. I've harvested some that became nutrient depleted in just 4 days. Others have taken weeks to get to become nutrient depleted. All things being the same as well. I've come to just accept that phyto is temperamental and just does its own thing.

Note that it takes a very long time for the culture to crash once nutrient depleted as long as you drastically reduce light and keep it bubbling. I experiment with mine all the time and usually 2 weeks it what it takes to start to loose color, but blooms again once more food is added. There's a few people on here that have legitimately good cultures that have been removed from bright light and have been going for a year and still bloom back to life once fed and lit up. This stuff is far more resilient than people give it credit for. Same with the whole "keep everything sanitary" nonsense. Just don't be an ignorant fool and the cultures will be fine lol. I encourage everyone concerned about cultivating to start reading the many peer reviewed scientific journals covering it. It's been researched to death so the info is out there.

 

[Anthony Scholfield]

There's no set time for harvesting. I've harvested some that became nutrient depleted in just 4 days. Others have taken weeks to get to become nutrient depleted. All things being the same as well. I've come to just accept that phyto is temperamental and just does its own thing.

Note that it takes a very long time for the culture to crash once nutrient depleted as long as you drastically reduce light and keep it bubbling. I experiment with mine all the time and usually 2 weeks it what it takes to start to loose color, but blooms again once more food is added. There's a few people on here that have legitimately good cultures that have been removed from bright light and have been going for a year and still bloom back to life once fed and lit up. This stuff is far more resilient than people give it credit for. Same with the whole "keep everything sanitary" nonsense. Just don't be an ignorant fool and the cultures will be fine lol. I encourage everyone concerned about cultivating to start reading the many peer reviewed scientific journals covering it. It's been researched to death so the info is out there.

Curious how you know yours has or has not become nutrient depleted? How are you measuring this?

Also there is somewhat of a set time to harvest phyto from culture start. It has to do with the cell count of the phytoplankton species you are culturing. There are ways to measure this and each species has a plateau density. Florida aqua farms sells a tool that will give you good estimates of your cell count. There is also a more involved way with a microscope and a hemocytometer. The 6-10 days is often cited because that is the typical range of when the culture has reached its plateau. Factors such as light, temp, and fertilizer can play a role. So having a tool to get an idea on cell count takes some of the guessing out.

For example: say at day 5 you measure and your cell count is approx. 1.3 million. Measure day 6 at 1.5 million. measure day 7 at 1.8 million. Maybe you go another day and find the measurement increases or stays the same. Once it stays about the same the plateau has been reached and its harvest time.

Once a culture has reached a plateau it will crash if left too long before being put into cold storage. If your phyto has lost color then you add more fertilizer and see more color. im willing to bet you are no longer culturing the phytoplankton you think you are. It is easy to grow green water but not as easy to culture solid phytoplankton. You would need a microscope to know for sure.

Yes phyto in cold storage will last up to 30 days for a good culture restart, even up to 90 days. Also, sanitation is actually quite important. Many other microbes and bacterias can out compete and take over a phyto culture. Like i said, growing green water is easy. Culturing a phytoplankton species you intended to grow isnt as easy. Still not that difficult but a bit more care is involved than you have expressed.

 

[Eldredge]

Curious how you know yours has or has not become nutrient depleted? How are you measuring this?

Also there is somewhat of a set time to harvest phyto from culture start. It has to do with the cell count of the phytoplankton species you are culturing. There are ways to measure this and each species has a plateau density. Florida aqua farms sells a tool that will give you good estimates of your cell count. There is also a more involved way with a microscope and a hemocytometer.

Once a culture has reached a plateau it will crash if left too long before being put into cold storage. If your phyto has lost color then you add more fertilizer and see more color. im willing to bet you are no longer culturing the phytoplankton you think you are. It is easy to grow green water but not as easy to culture solid phytoplankton. You would need a microscope to know for sure.

Yes phyto in cold storage will last up to 30 days for a good culture restart, even up to 90 days. Also, sanitation is actually quite important. Many other microbes and bacterias can out compete and take over a phyto culture. Like i said, growing green water is easy. Culturing a phytoplankton species you intended to grow isnt as easy. Still not that difficult but a bit more care is involved than you have expressed.

I completely agree with this.

 

[LgTas]

Curious how you know yours has or has not become nutrient depleted? How are you measuring this?

Also there is somewhat of a set time to harvest phyto from culture start. It has to do with the cell count of the phytoplankton species you are culturing. There are ways to measure this and each species has a plateau density. Florida aqua farms sells a tool that will give you good estimates of your cell count. There is also a more involved way with a microscope and a hemocytometer. The 6-10 days is often cited because that is the typical range of when the culture has reached its plateau. Factors such as light, temp, and fertilizer can play a role. So having a tool to get an idea on cell count takes some of the guessing out.

For example: say at day 5 you measure and your cell count is approx. 1.3 million. Measure day 6 at 1.5 million. measure day 7 at 1.8 million. Maybe you go another day and find the measurement increases or stays the same. Once it stays about the same the plateau has been reached and its harvest time.

Once a culture has reached a plateau it will crash if left too long before being put into cold storage. If your phyto has lost color then you add more fertilizer and see more color. im willing to bet you are no longer culturing the phytoplankton you think you are. It is easy to grow green water but not as easy to culture solid phytoplankton. You would need a microscope to know for sure.

Yes phyto in cold storage will last up to 30 days for a good culture restart, even up to 90 days. Also, sanitation is actually quite important. Many other microbes and bacterias can out compete and take over a phyto culture. Like i said, growing green water is easy. Culturing a phytoplankton species you intended to grow isnt as easy. Still not that difficult but a bit more care is involved than you have expressed.

What would make up the green water if not phyto? Cyano?

 

[Anthony Scholfield]

What would make up the green water if not phyto? Cyano?

sure, cyano could be one. Cant say i have all the answers for that. Green water doesnt always equate to phytoplankton or at least the phytoplankton youre intending to culture. There are alot of microbes out there and other little critters. Looking under a microscope is the only true way to know.

 

[LgTas]

sure, cyano could be one. Cant say i have all the answers for that. Green water doesnt always equate to phytoplankton or at least the phytoplankton youre intending to culture. There are alot of microbes out there and other little critters. Looking under a microscope is the only true way to know.

Thanks mate. Will have to fire up the old girl tomorrow and see what I've been dumping in my tank the last couple months.

 

[LgTas]

Double post

 

[LgTas]

Just to close the loop. I checked my samples and confirmed they appear to only have nannochloropsis with no cyano contamination.

I'm not super careful and don't decontaminate etc. and I've been producing for over a year now.

 

[onlyfans]

Curious how you know yours has or has not become nutrient depleted? How are you measuring this?

Also there is somewhat of a set time to harvest phyto from culture start. It has to do with the cell count of the phytoplankton species you are culturing. There are ways to measure this and each species has a plateau density. Florida aqua farms sells a tool that will give you good estimates of your cell count. There is also a more involved way with a microscope and a hemocytometer. The 6-10 days is often cited because that is the typical range of when the culture has reached its plateau. Factors such as light, temp, and fertilizer can play a role. So having a tool to get an idea on cell count takes some of the guessing out.

For example: say at day 5 you measure and your cell count is approx. 1.3 million. Measure day 6 at 1.5 million. measure day 7 at 1.8 million. Maybe you go another day and find the measurement increases or stays the same. Once it stays about the same the plateau has been reached and its harvest time.

Once a culture has reached a plateau it will crash if left too long before being put into cold storage. If your phyto has lost color then you add more fertilizer and see more color. im willing to bet you are no longer culturing the phytoplankton you think you are. It is easy to grow green water but not as easy to culture solid phytoplankton. You would need a microscope to know for sure.

Yes phyto in cold storage will last up to 30 days for a good culture restart, even up to 90 days. Also, sanitation is actually quite important. Many other microbes and bacterias can out compete and take over a phyto culture. Like i said, growing green water is easy. Culturing a phytoplankton species you intended to grow isnt as easy. Still not that difficult but a bit more care is involved than you have expressed.

I primarily only worry about Iso and Porphy, so if there is ever green in my system something is very very wrong. But yes, I know about the potential of other 'things' growing in it. Literally anyone that cultivates should know this already.

Yes, you are correct about cell count and all of that. I was simply dumbing it down because the 95% of people cultivating do not understand any of that and want the easiest set and forget setup they can have. So, from a generalization standpoint, a simple vinegar scrub and RODI rinse is plenty for your standard person that doesn't want to put the extra effort in. This may be showing "careless ness" as you've expressed, but again, to the typical person it is normal because it is easy.

Your statement about plateau and culture crash and how it needs to be put into cold storage is simply false. A very small amount of f/2 and low light with constant aeration is all it takes to keep them happy for a long time *assuming everything is sanitary, perfectly set up, and it's checked on periodically*, felt I needed to add that for clarification for you. Or you could keep believing the big name brands telling you to refrigerate it that harvest well in advance of shipping and put it into cold storage themselves starting the decay process of the cells, aka death. But hey, what do I know.

We could get super nerdy about it and discuss different methods on how to increase cell density and lipids through light intensity, light color spectrum, nutrients, how many micro mols of what will effect what etc etc. But again, most people don't understand nor care about all of that, only those of us in science fields do.

To answer your question, the cool nerdy way is with a centrifuge plus other laboratory equipment and processes. It's not that difficult but involved, and again, it's in peer reviewed scientific journals as well as detailed information on the typical length of time it takes for Guillard's f/2 to deplete under different conditions. Or if you're low tech just have some pods or other organisms that don't eat the f/2 nutrients eat all the phyto and take a small sample from that. I'm sure any number of test kits will help to approximately determine nutrient levels with this method.

 

[Mirkus]

Uh oh, what is this?!! It is moving all over the place. I thought nann does not move.

 

[Mirkus]

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[Mirkus]

More magnification.. I think it’s tetraselmis, not nannochloropsis

 

[britnicole1724]

Curious how you know yours has or has not become nutrient depleted? How are you measuring this?

Also there is somewhat of a set time to harvest phyto from culture start. It has to do with the cell count of the phytoplankton species you are culturing. There are ways to measure this and each species has a plateau density. Florida aqua farms sells a tool that will give you good estimates of your cell count. There is also a more involved way with a microscope and a hemocytometer. The 6-10 days is often cited because that is the typical range of when the culture has reached its plateau. Factors such as light, temp, and fertilizer can play a role. So having a tool to get an idea on cell count takes some of the guessing out.

For example: say at day 5 you measure and your cell count is approx. 1.3 million. Measure day 6 at 1.5 million. measure day 7 at 1.8 million. Maybe you go another day and find the measurement increases or stays the same. Once it stays about the same the plateau has been reached and its harvest time.

Once a culture has reached a plateau it will crash if left too long before being put into cold storage. If your phyto has lost color then you add more fertilizer and see more color. im willing to bet you are no longer culturing the phytoplankton you think you are. It is easy to grow green water but not as easy to culture solid phytoplankton. You would need a microscope to know for sure.

Yes phyto in cold storage will last up to 30 days for a good culture restart, even up to 90 days. Also, sanitation is actually quite important. Many other microbes and bacterias can out compete and take over a phyto culture. Like i said, growing green water is easy. Culturing a phytoplankton species you intended to grow isnt as easy. Still not that difficult but a bit more care is involved than you have expressed.

What tool does Florida aqua farms sell? I have no idea how to use a hemocytometer but I do have a microscope just curious for my own knowledge if I’ve been harvesting too soon

 

[Anthony Scholfield]

What tool does Florida aqua farms sell? I have no idea how to use a hemocytometer but I do have a microscope just curious for my own knowledge if I’ve been harvesting too soon

It’s a micro algae density meter. A dip stick if you will. It isn’t 100% accurate but will give you a good estimate of your cell count. If you go to their website you’ll find it there. It’s about $9.00.