I bought a 500mL Nannochloropsis culture from eBay and thought I'd see if I could keep it alive with a few things I had lying about the house. I couldn't easily get my hands on specific algae culture media, and I wasn't too keen on maintaining a perfectly sterile culture environment, so I wanted to see if the quick and dirty approach works. 3 months later it's turned out pretty well so far!
I thought I'd share my experience for anyone else interested in a less complex Nannochloropsis culture method. I wouldn't recommend this method if you're culturing at scale, or if you're concerned about putting extra nitrate or phosphate (or whatever else might be in the fertiliser) into your tank.
The key points are:
- I used standard plant fertiliser
- Tap water with dechlorinator
- No heater; average temperature about 12-15 degrees celsius (something like 54-59 degrees F)
- 12h photoperiod
Equipment I used:
10L tank
Cheap hang on back pump with filter media removed (similar to this)
Cheap freshwater light (something like this)
Timer (I've had a really good experience with the TP-Link Kasa series of smart plugs/powerboards)
Extremely cheap, no-name plant fertiliser
Blue treasure salt (I got 20kg for $50 AUD)
Refractometer
Dechlorinator
Off-brand fertiliser
Method:
I cleaned the tank with soap and water, then rinsed with boiling tap water.
I filled the tank with about 9L of tap water, and put in a few drops of dechlorinator
Added the marine salt to get a standard gravity of 1.20 (was about 200g salt to the 9L of water)
Added 100mL of Nannochloropsis culture
Added a pinch (probably 2-3g) of crushed up fertiliser pellets
Installed the HOB pump to get some water movement
Set the light to a 12h photoperiod
The (ghetto) setup
Harvesting:
I take about 2L per week of the Nannochloropsis culture. This goes in the fridge (and serves as a backup in case the main culture crashes).
After 2 weeks (i.e. 4L harvested), I add 4L of dechlorinated tap water made to standard gravity ~1.15 to replenish this.
With each top-up I add another pinch of fertiliser.
The end result
Results:
It took about 4-5 days to notice that the water had become a darker green
After about 3 harvests (i.e. 3 weeks), the green was about the same intensity as the culture from eBay
In my tank:
- I noted an increase in copepods, and especially mysid shrimp (literally thousands of these) in my refugium (dosing ~2L per week into a 200L system)
- Nitrate and phosphate remain 0
- Corals look happy enough, but it might be too early to tell whether they've responded
My main aim was to maintain the culture over time without crashing, rather than keeping production at maximum.
After a water top-up, it seems to reach maximum density after about 2-3 days - and stays that way for the next 11-12 days until the next top-up
It remains to be seen whether the culture can survive at this density during the warmer months (the end of the year in my part of the world), but I suspect it'll be OK.
Mysid shrimp hanging around my return pump. Had a population explosion a few weeks after dosing Nannochloropsis
I know that Nannochloropsis is pretty easy to culture, and is probably not the best phytoplankton strain available for our purposes.
What this demonstrates is that it's really easy!
What do you think? Have I just been lucky so far? Am I risking a disastrous contamination of my culture and tank? Or is this pretty consistent with everyone else's experience?
I thought I'd share my experience for anyone else interested in a less complex Nannochloropsis culture method. I wouldn't recommend this method if you're culturing at scale, or if you're concerned about putting extra nitrate or phosphate (or whatever else might be in the fertiliser) into your tank.
The key points are:
- I used standard plant fertiliser
- Tap water with dechlorinator
- No heater; average temperature about 12-15 degrees celsius (something like 54-59 degrees F)
- 12h photoperiod
Equipment I used:
10L tank
Cheap hang on back pump with filter media removed (similar to this)
Cheap freshwater light (something like this)
Timer (I've had a really good experience with the TP-Link Kasa series of smart plugs/powerboards)
Extremely cheap, no-name plant fertiliser
Blue treasure salt (I got 20kg for $50 AUD)
Refractometer
Dechlorinator
Off-brand fertiliser
Method:
I cleaned the tank with soap and water, then rinsed with boiling tap water.
I filled the tank with about 9L of tap water, and put in a few drops of dechlorinator
Added the marine salt to get a standard gravity of 1.20 (was about 200g salt to the 9L of water)
Added 100mL of Nannochloropsis culture
Added a pinch (probably 2-3g) of crushed up fertiliser pellets
Installed the HOB pump to get some water movement
Set the light to a 12h photoperiod
The (ghetto) setup
Harvesting:
I take about 2L per week of the Nannochloropsis culture. This goes in the fridge (and serves as a backup in case the main culture crashes).
After 2 weeks (i.e. 4L harvested), I add 4L of dechlorinated tap water made to standard gravity ~1.15 to replenish this.
With each top-up I add another pinch of fertiliser.
The end result
Results:
It took about 4-5 days to notice that the water had become a darker green
After about 3 harvests (i.e. 3 weeks), the green was about the same intensity as the culture from eBay
In my tank:
- I noted an increase in copepods, and especially mysid shrimp (literally thousands of these) in my refugium (dosing ~2L per week into a 200L system)
- Nitrate and phosphate remain 0
- Corals look happy enough, but it might be too early to tell whether they've responded
My main aim was to maintain the culture over time without crashing, rather than keeping production at maximum.
After a water top-up, it seems to reach maximum density after about 2-3 days - and stays that way for the next 11-12 days until the next top-up
It remains to be seen whether the culture can survive at this density during the warmer months (the end of the year in my part of the world), but I suspect it'll be OK.
Mysid shrimp hanging around my return pump. Had a population explosion a few weeks after dosing Nannochloropsis
I know that Nannochloropsis is pretty easy to culture, and is probably not the best phytoplankton strain available for our purposes.
What this demonstrates is that it's really easy!
What do you think? Have I just been lucky so far? Am I risking a disastrous contamination of my culture and tank? Or is this pretty consistent with everyone else's experience?
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