How to avoid Phytoplankton crashes
- Thread starter melev
- Start date
The commercial guys selling concentrated bottles of phyto use a centrifuge to concentrate it. Filters would clog far too fast to be practical. IME, just getting it to that point of max growth is good enough for most of us. No worse of a nutrient addition at that point than feeding dry foods to the fish 
F/2 sold commercially only has 0.88 mM NaNO3 and 0.0362 mM NaH2PO4*H2O in the final medium. The exact recipe is given on the NCMA website.This means the medium contains 56.45 mg/L nitrate. Dosing 100 mL of that solution directly into a 50 gallon/189.271 L tank would add 5.645 mg nitrate to the tank, which over 50 gal would increase the nitrate concentration by about 0.03 ppm.
That isn't a a big dose, and those calculations do not even account for the fact that the microalgae will consume a large proportion of the nitrate.
My calculations are below in case I made a mistake. I don't do stoic often.
[NO3] = 0. 882 mM
NO3 moar mass = 64.0049 g/mol
64.0047 g/mol * 0.882 mM = 0.05645 g NO3 per L of F/2.
0.1 L * 0.05645 g/L = 5.645 mg NO3
5.645 mg / 189.271 L = 0.0298 mg/L increase.
That isn't a a big dose, and those calculations do not even account for the fact that the microalgae will consume a large proportion of the nitrate.
My calculations are below in case I made a mistake. I don't do stoic often.
[NO3] = 0. 882 mM
NO3 moar mass = 64.0049 g/mol
64.0047 g/mol * 0.882 mM = 0.05645 g NO3 per L of F/2.
0.1 L * 0.05645 g/L = 5.645 mg NO3
5.645 mg / 189.271 L = 0.0298 mg/L increase.
Last edited:
When replacing evaporated water volume, use RO.
When splitting a culture, use salt water.
I found that taking out no more than about 50% of the phyto to use and then adding the new salt water and fertilizer gave me fewer crashes than any other way.
Pretty hard to NEVER have crashes unless you have a sterile room and equipment as ever-present bacteria can play havoc with your cultures. For that reason, the more culture containers you use, the better the odds are of always having enough when you need it. I maintain ten 2 litre bottles of nanno in constant culture and probably have 1 or two of those bottles crash each month or two.
When splitting a culture, use salt water.
I found that taking out no more than about 50% of the phyto to use and then adding the new salt water and fertilizer gave me fewer crashes than any other way.
Pretty hard to NEVER have crashes unless you have a sterile room and equipment as ever-present bacteria can play havoc with your cultures. For that reason, the more culture containers you use, the better the odds are of always having enough when you need it. I maintain ten 2 litre bottles of nanno in constant culture and probably have 1 or two of those bottles crash each month or two.
I use open ended rigid airline tubing and for two litre bottles I have a low flow, just enough to keep the culture in some motion.
When I was doing large scale production, the larger the container, the more the flow rate to be able to keep the nanno in suspension as nanno is a non-motile algae.
I used to use 5g pails as well as 26g Rubbermaid containers when my needs were greater, and, I was selling to others.
Now, it's hard to use the 26g containers anymore because I cannot buy SPOT LIGHTS that were critical for light to reach depths of the container. Flood lights just don't have the penetration power of the old spots.
http://www.angelfire.com/ab/rayjay/phyto.html
When I was doing large scale production, the larger the container, the more the flow rate to be able to keep the nanno in suspension as nanno is a non-motile algae.
I used to use 5g pails as well as 26g Rubbermaid containers when my needs were greater, and, I was selling to others.
Now, it's hard to use the 26g containers anymore because I cannot buy SPOT LIGHTS that were critical for light to reach depths of the container. Flood lights just don't have the penetration power of the old spots.
http://www.angelfire.com/ab/rayjay/phyto.html
16 hours of light daily seems excessive, phyto splits and multiplies quickly, you need to harvest it daily if you want to give it 16 hours light. If you don’t need to harvest it everyday, then you should adjust your food source for phyto to grow slower. Maybe 8 hours of sun. As little nitrogen...
FWIW, I light the cultures 24/7 and I definitely don't harvest daily or even close to it these days with sometimes two weeks or more before getting back to a replenished bottle. I have had in the past, times when a culture continued over a month before being used.
My cultures can be split many times and still have the same dark appearance as the original. Customers thought I had a centrifuge to concentrate the nanno but all it takes is more time and fertilizer.
In over 24 yrs now I've never had a culture ready for harvest in even a couple of days, at least to get the same intensity on the density stick which I consider ready when it reads 2.5 cm or less.
My cultures can be split many times and still have the same dark appearance as the original. Customers thought I had a centrifuge to concentrate the nanno but all it takes is more time and fertilizer.
In over 24 yrs now I've never had a culture ready for harvest in even a couple of days, at least to get the same intensity on the density stick which I consider ready when it reads 2.5 cm or less.
This might help you
http://www2.ca.uky.edu/wkrec/PhytoplanktonAlgaeCulture.pdf
It’s basic plant keeping, just make it simple.
http://www2.ca.uky.edu/wkrec/PhytoplanktonAlgaeCulture.pdf
It’s basic plant keeping, just make it simple.
That's hard to say when I don't know what the starting density is, and what it is now. Appearances are deceiving when going by sight.
I much prefer using a density stick so I actually know what I have at any time.
https://www.youtube.com/watch?v=3FAVUfYrV0g
http://floridaaquafarms.com/shop/microalgae-density-measurer/
As I say, this is my preference, but many others do well WITHOUT a density stick so Akram could advise on that method.
One that video, the segment showing the comparison of left and right cultures and their related densities shows how hard it can be to know the darker cultures which for me is nannochloropsis.
I much prefer using a density stick so I actually know what I have at any time.
https://www.youtube.com/watch?v=3FAVUfYrV0g
http://floridaaquafarms.com/shop/microalgae-density-measurer/
As I say, this is my preference, but many others do well WITHOUT a density stick so Akram could advise on that method.
One that video, the segment showing the comparison of left and right cultures and their related densities shows how hard it can be to know the darker cultures which for me is nannochloropsis.
