To be economically feasible, open ponds simply will not work. Too many variables can occur making production erratic. Providing an optimum environment in a closed reactor seems much more feasible. My company is working on a road transportable reactor which can promote the conditions that will create a "super-bloom" condition on a continuous basis. A distributed system of many small tanks, versus a few big tanks, will allow for sterilization and re-inoculation when the inevitable colony collapse occurs without shutting down all production. Water will become as valuable as oil soon, the areas that provide the best potential for growth are mostly short of water. The evaporation loss on open ponds will be huge. Water will have to be conditioned, recycled, and reused, locally; where ever that may happen to be.

Most of the thoughts and ideas in this group are turning around the production of bio fuel. Here are some facts:
For the oil-industry it seems to be economical feasible if algae-bio-diesel is being produced for 0,48 $ per litre in an ordering amount of 210 million litre – which equals the yearly requirement of 2000.000 standard model factory car. For such a production a floor space of 85 square kilometre would be necessary. The liquid volume would be 17.2 cubic metre. This amount of liquid has to be kept floating steadily, daily harvest of at least half of the reactor has to be undertaken daily, the biomasses have to be dried, and, and and ……
All this for keeping the good old combustion engines running. They are antiques, inventented in 1862 (by Nikolaus August Otto, remember!?),in a sophisticated package with a lot of electronic gimmics around. This technology is out-dated and it`s about time to invent something new.
Algae are the feedstock for a number of biomaterials including food and feed that are more important to produce than bio fuel.

1.The most cost effective way to prevent contamination in open pond is to use no open ponds! Use covered ponds.
2.Continious harvesting methods which return species too small, thus ensuring an undisturbed breeding cycle is possible. With the same process nutrients and CO2 can be applied.
3.Taking algae from the ocean. What is with the rest of sealife, - zooplankton? - you skim that off too and ther is no way to prevent that, you disturb the food chain of a lot of other inhabitants.
4.Fertilising the seawaters. What are the consequences?
The same goes for ideas to add mutant species for better lipid production. How can one controll such action in the open sea?

I don't believe preventing contamination by unwanted species of algae is possible.
I think it is more feasible to use local species even if it is not the most productive in open ponds.
I like originoil's method of removing 90% and leaving 10% of the algae in a closed system for replenishment. In their system control can be maintained of contamination, nutrients and lighting.
Too bad we can't look at a system like that to validate its operation. Any Ideas?

During the Carter adminstration (1977..81) it was estabished that preventing contamination in open ponds was almost impossible. It was one of the main conclusions after a lot of research during that time.

Cyanotech and Earthrise have been making money for 20+ years producing algaefor nich markets (nutraceuticals).

My question about preventing contamination in open ponds is about the comparison between genetically engineered high-yielding species and species that are cultured naturally. It may be better to accept presence of other species in the mix if a desired species is dominant. So the challenge is to continually select and cultivate the most robust natural strain, to encourage rapid adaptation towards high yield and ability to thrive together with wild strains of algae.

I agree with Solgaribay.

Duration of culture is important, I think contamination can be prevented if you shorten the culture period!

Not sure what type of contamination are we talking about.. I would assume organic or metal contaminant.. if that is the case, most metals are biologically reducible, and most organics are also biodegradable given the correct environmental conditions (nutirents and electron acceptors which is oxygen in this case). What if we create a hybrid pond of algae and bacteria? The algae would provide the oxygen and the bacteria would clean-up the contamination and provide CO2 to the algae, not sure if such systems have been tested.. I would like to hear some thoughts on that.. Thank you

Ocean based algae production, contained and managed within floating polymer bags of fresh water, can breed strains of oil-producing algae that will compete with wild strains. If an ocean pond has multiple parallel tracks, the track that gives the best yield can be fed back to seed the system. Robust natural adaptation using plant husbandry is the way to go. I don't trust genetic engineering.

I think that the only way to use marine algae. And may be not effective

1.using marine strains that can grow in high salinity
2.Using algae like diatoms which are less prone to contamination
3.when upscaling for higher volumes if we transfer cultures with high cell density will minimize contamination
from my experience it is highly difficult to maintain algal cultures with zero contamination in open ponds

I think it might be a way out if we use DSP of various metabolites present in the bottom of the pond..by extracting them....

Water chemistry and light spectrum dominance, it is all about - after spending the best part of 5 years, working researching in this field it all about what compounds are sharing the space with the algae. Difference species dominance require specific nutrient requirement , after looking in a vast number of wild effluent ponds and the species breakdown, nutrient and seasonal (relating to light) variations are the defining factor in the oil/fat sugar contents of algae bloom.

I think, strain selection(wild) and usage of salt and natural pesticides like cow urine and cow dung in the surroundings, will help in the process

I think that for now I have to agree with "4algae" to some degree at least. I agree that it is impossible to use open ditch
technology to remediate medium to large CO2 stationary plants.
In our case it would take 21 square miles of open ditch area.
Think of all the piping, the surface evaporation, the temperature control problems, the constant battle against contamination, leaks, replace plastic every 5 years, the list goes on and on!! And all of this for a system that only works less than half the time.

I think the best way is to choose the best native strain for the open system under consideration...this way, contamination can be prevented to a very large extent "naturally"

if we use sea weeds for fuel production, lot cost may reduced. cultivation cost as well as contamination and maintenance cost may reduce by setting cultivation in the open sea.

Using sea water and marine algae also puts an end to the food vs fuel debate.

Well I am convinced that the production rate for open pond will not meet the return on investment.

No one has yet to publish any business that has turn any level of profit in open and closed systems that I am aware of. Even just a standard accounting showing the percentage of costs and profit is what we need to all try to show. Investors want return on investment. How can we expect this to a business if no one can show the profit potential.
Does anyone know of a business that is making oil from algae that is willing to show there numbers ?

The easiest way is to use salt water and marine algae. The further inland one is located the better this should work.