Andy Pierce
Member
Thinking more about whether EI is still relevant and related considerations around algae, the idea occurs around limiting algae growth to look at what people are doing who are really trying to grow algae, and then don't do what they are doing.
In OPTIMIZATION OF GROWTH CONDITIONS OF DIFFERENT ALGAL STRAINS AND DETERMINATION OF THEIR LIPID CONTENTS algae likes temperatures between 24-28C, pH that is neither low nor high, so ideally 7.5, and prefers fluorescent light to sunlight - there is some data that intense light can be damaging to algae (multiple sources say this). Mixing and aeration are both beneficial to algae.
In Growth parameters and responses of green algae across a gradient of phototrophic, mixotrophic and heterotrophic conditions authors mention there is good data that algae does well with organic carbon - they used sodium acetate and commented this is commonly used to make 'synthetic wastewater'. To be fair, I have suspected that high levels of organic waste (organic carbon) promote algae growth and have tried reasonably vigorously to remove these.
In Algae Growth and Reaction Conditions algae growth is listed as being enhanced by temperature between 20-30C, by light that is neither too strong nor too weak, aeration/mixing, pH that is neutral to slightly alkaline.
Lots of good data in The Growth Factors Involved in Microalgae Cultivation for Biofuel Production: A Review as well, with similar conclusions.
Of course, some of the factors that optimise algae growth will also optimise the growth of the plants we want. I now more strongly suspect the contribution of organic carbon (rotting materials) to be part of the problem. I had thought good water flow would help prevent algae, but apparently algae likes that too. The light intensity thing is interesting as well. I have mitigated algae I believe successfully be reducing the lighting, but there is also the idea now that you could increase the lighting to have a similar effect. Whether algae would be more photosensitive that other plants is obviously a question. I have wondered how @Aquarium Gardens keeps their tanks looking so great - they have very intense (from my perspective) lighting, but maybe that is part of the secret.
In OPTIMIZATION OF GROWTH CONDITIONS OF DIFFERENT ALGAL STRAINS AND DETERMINATION OF THEIR LIPID CONTENTS algae likes temperatures between 24-28C, pH that is neither low nor high, so ideally 7.5, and prefers fluorescent light to sunlight - there is some data that intense light can be damaging to algae (multiple sources say this). Mixing and aeration are both beneficial to algae.
In Growth parameters and responses of green algae across a gradient of phototrophic, mixotrophic and heterotrophic conditions authors mention there is good data that algae does well with organic carbon - they used sodium acetate and commented this is commonly used to make 'synthetic wastewater'. To be fair, I have suspected that high levels of organic waste (organic carbon) promote algae growth and have tried reasonably vigorously to remove these.
In Algae Growth and Reaction Conditions algae growth is listed as being enhanced by temperature between 20-30C, by light that is neither too strong nor too weak, aeration/mixing, pH that is neutral to slightly alkaline.
Lots of good data in The Growth Factors Involved in Microalgae Cultivation for Biofuel Production: A Review as well, with similar conclusions.
Of course, some of the factors that optimise algae growth will also optimise the growth of the plants we want. I now more strongly suspect the contribution of organic carbon (rotting materials) to be part of the problem. I had thought good water flow would help prevent algae, but apparently algae likes that too. The light intensity thing is interesting as well. I have mitigated algae I believe successfully be reducing the lighting, but there is also the idea now that you could increase the lighting to have a similar effect. Whether algae would be more photosensitive that other plants is obviously a question. I have wondered how @Aquarium Gardens keeps their tanks looking so great - they have very intense (from my perspective) lighting, but maybe that is part of the secret.