Phytoplankton culture

[mikebusc]

I've recently been interested in culturing my own phyto. I studied up on it and tried my first batch but it never grew. I think I may have been a little lax on my sterilization technique.
But after some more reading I found info saying I need to start with a starter culture. And a single strain also. Is a "starter culture" different then the phyto I've been using from BRS? Or is this company just trying to make their sale?

 

[DaJMasta]

Any live algae culture can be a starter culture, and usually you do go with a single strain because they will compete with each other and end up mostly that way in the end - single strain makes sure you get what you're intending and that it's easy to know if contamination has happened.

While sterilization technique is important to keeping a culture going healthy in the long term, you basically only need live algae cells, water, fertilizer, light, and agitation to get it to grow reasonably, the requirements are pretty broad and basic. It's possible to salinity shock and kill live phyto, so it's important to take a few hours acclimating it if you know it's from a different salinity culture, and it's essential that the starting culture is live and not a concentrate. Beyond that, a suitable fertilizer isn't hard to find (and while most fertilizers will grow it, many don't have the right proportions or things you want to ultimately put in your tank, so get one for marine algae specifically), then get a reasonably bright looking light (doesn't have to be crazy par, but if it looks dim, it's not going to do well), and run some air bubbles through it for agitation/gas exchange.

 

[mikebusc]

Any live algae culture can be a starter culture, and usually you do go with a single strain because they will compete with each other and end up mostly that way in the end - single strain makes sure you get what you're intending and that it's easy to know if contamination has happened.

While sterilization technique is important to keeping a culture going healthy in the long term, you basically only need live algae cells, water, fertilizer, light, and agitation to get it to grow reasonably, the requirements are pretty broad and basic. It's possible to salinity shock and kill live phyto, so it's important to take a few hours acclimating it if you know it's from a different salinity culture, and it's essential that the starting culture is live and not a concentrate. Beyond that, a suitable fertilizer isn't hard to find (and while most fertilizers will grow it, many don't have the right proportions or things you want to ultimately put in your tank, so get one for marine algae specifically), then get a reasonably bright looking light (doesn't have to be crazy par, but if it looks dim, it's not going to do well), and run some air bubbles through it for agitation/gas exchange.

Thanks for a very concise answer. I just ordered Nannochloropsis starter and I used F2 on the last one. I do have a pump and good light on a timer. I definitely wasn't aware of the salinity factor. I never thought of acclimating. Will try this in a couple of weeks when it comes in?
Also, to keep the culture going, once if grows, do I take out half of it and then add more saltwater and fertilizer? And potentially never need to buy it again?

 

[JTP424]

Thanks for a very concise answer. I just ordered Nannochloropsis starter and I used F2 on the last one. I do have a pump and good light on a timer. I definitely wasn't aware of the salinity factor. I never thought of acclimating. Will try this in a couple of weeks when it comes in?
Also, to keep the culture going, once if grows, do I take out half of it and then add more saltwater and fertilizer? And potentially never need to buy it again?

Potentially correct. You'll need to buy fertilizer and provide saltwater and ensure a sterile environment etc. But it should be self sustaining.

 

[mikebusc]

Great! I'll give it another go.

 

[DaJMasta]

For acclimation, you'll likely be able to smell in the first 12 hours if it needed it and didn't get it, but for me, by default now, I just take the new culture, add about 50% of that culture's total volume worth of new seawater I intend to use, wait a few hours, add another 50-100%, wait a few hours, then add as much as I want to fill out the culture. For fertilizer, F/2 or its derivatives are the standard, and you just need to add about as much as it says on the formulation (for the Fritz stuff I use, it's around 0.5mL per part per gallon.)

A timer is not strictly required - they can live and grow with a 24 hour photoperiod, but you can slow that growth or just give yourself a little darkness with a timer without issue. I wouldn't go under 8 hours a day of lighting, but they likely could get by with less. I like to keep my cultures a little under a rolling boil in terms of agitation, it does help keep some of the more sinking prone algae in suspension, but it also makes sure there's plenty of gas exchange to get more CO2 to every cell that can use it.

I wouldn't call nannochloropsis the hardiest of strains, especially when it comes to keeping contamination out, but meeting the basic needs of any algae should get you to reasonable density without much effort in a week or two, so if it all dies or something, there must be something critical being overlooked.

 

[mikebusc]

Are there any recommendations on what strain of phyto is better than another? Or are they used for different things?