Algae culture, a good reference for understanding how they grow...........

[Tom Barr]

and what Influence their growth rates:


Algal cultures and phytoplankton ecology - Google Books

I have Andersen's book, but this one is not bad.

This one gives good detail to the growth phase of algae, the lag, the exponential, stationary and death phase of cultures. How might the stage of the life history affect results if you tested algae and "cures"?


Also, there is a nice graph about the effects of light on growth rate and uptake in algae.

Differences between species in competition etc.

Regards,
Tom Barr

[Tom Barr]

ANOTHER PAPER:

http://isis.ku.dk/kurser/blob.aspx?feltid=199535

Regards,
Tom Barr

[Philosophos]

Nice link, Tom; I've got the first one bookmarked. That second link is giving me timed out connection.

-Philosophos

[dutchy]

Thanks Tom, some more good reading. The second link worked ok here.

Regards,
Dutchy

[Tom Barr]

Nice link, Tom; I've got the first one bookmarked. That second link is giving me timed out connection.

-Philosophos

It's a dowloadable pdf
Takes longer to load.


Regards,
Tom Barr

[Philosophos]

It's working today. My pdf's respond fast; foxit .pdf reader does a good job of things.

I gave the entire thing a first pass. Here are my primary notes:

pg 137 - LOW nutrient availability causing algae? Being written about in a paper back in 1991? Interesting.

pg 142 - CaCO3 is precipitated by algae? is it a byproduct or was the same CaCO3 present before the algae, too?

pg 145 - The 550:30:1 CNP from Atkinson and Smith is interesting next to the more common 106:16:1, and actually shows that less complex algae requires less PO4 than macroalgaes. How did we become so confused as to say PO4 causes algae?

pg 147 - If light levels effect the algae type present, is it possible that low light would not only slow growth, but induce possibly less competitive types of algae? Are there any studies on inducing algae types through altering light levels? More unicellular algae perhaps?

151 - Regarding the loss of dissolved organic compounds, if the first hypotheses is true, wouldn't it become apparent that algaes biomass does not increase in direct proportion with light levels, if light were the only altered variable? Does this same process happen with macrophytes?

154 - So does this page explain why we end up with a little hair algae near the base of large clusters of stem plants in the aquarium?

159 - High plant density may reduce algae through released organic substances. Need to read more on this

161 - Horrible graph

163 - What prevents algae from being temperature limited? Is a hotter tank (presuming it does not stress the plants) better for out-competing algae?

Overall I found the paper a more productive read than most of what I dig up. I'm going to give this paper a 2nd pass in a couple of days and see if I can't get my hands on some of the source studies they list.

Nice find, Tom.

-Philosophos

[Tom Barr]

[QUOTE=Philosophos;41561]It's working today. My pdf's respond fast; foxit .pdf reader does a good job of things.

I gave the entire thing a first pass. Here are my primary notes:

pg 137 - LOW nutrient availability causing algae? Being written about in a paper back in 1991? Interesting.

pg 142 - CaCO3 is precipitated by algae? is it a byproduct or was the same CaCO3 present before the algae, too?

pg 145 - The 550:30:1 CNP from Atkinson and Smith is interesting next to the more common 106:16:1, and actually shows that less complex algae requires less PO4 than macroalgaes. How did we become so confused as to say PO4 causes algae?

[quote]

Easily, folks focused too much on marine algae and Redfield's ratio rather than looking at specific algae and their specific ratio.

Called being too lazy to do a comparative analysis to see if they could make a more general conclusion about warmer water freshwater periphytic algae.
I've looked quite a bit over the years, but I can make few generalizations myself, have no clue how these other clowns can They still try to say a lot more than they can based on the support.

CaCO3 is a common by product and many species use it to form shells, coraline algae, many marine species use it and a great deal of it actually.

Low nutrients cause shifts in the species compositions typically, often going from nice big algae to smaller microphytes, same deal for FW systems, lower nutrients => less plants.
Difference in FW systems, access to sediments via roots.

So you have to test.measure the sediments+ water column BOTH.
Hobbyist do not do this.

pg 147 - If light levels effect the algae type present, is it possible that low light would not only slow growth, but induce possibly less competitive types of algae? Are there any studies on inducing algae types through altering light levels? More unicellular algae perhaps?

Sounds reasonable to me.
Weakens them and slows growth rates generally, some have a better competitive advantage than others at lower light, the same is true for many aquatic plants. A Big deal in aquatic weed studies.

151 - Regarding the loss of dissolved organic compounds, if the first hypotheses is true, wouldn't it become apparent that algaes biomass does not increase in direct proportion with light levels, if light were the only altered variable? Does this same process happen with macrophytes?

154 - So does this page explain why we end up with a little hair algae near the base of large clusters of stem plants in the aquarium?

163 - What prevents algae from being temperature limited? Is a hotter tank (presuming it does not stress the plants) better for out-competing algae?

Overall I found the paper a more productive read than most of what I dig up. I'm going to give this paper a 2nd pass in a couple of days and see if I can't get my hands on some of the source studies they list.

Nice find, Tom.

-Philosophos

Well, it's just one study.
You need to look at how/why, does it seem reasonable, does their data support their conclusions etc yada yada yada.........

Most of the papers I post tend to be thought provoking, rather than models. Get the brain questioning, then see what we can say, do with aquariums/plants.

Regards,
Tom Barr

[Philosophos]

Thanks for the reply, Tom; it's nice getting a little clarification on something like this. I really enjoyed this paper more than most; dealing with concepts rather than specific data about the limnology of some backwoods lake made it almost like reading a text book.

If I can't get any of the more frequently sourced papers, I'm definitely going to look around and see what other information supports it. Or better yet, what information contradicts it.

-Philosophos

[Tom Barr]

Old trick: read the citations of good papers.
Look those papers up

Also, work google scholar with different key words, example, you'll get much more from something like "periphyton" vs say..."algae and nutrients".

Be specific as you can, research is/tends to be.

Use the species/genus name, use a narrow focus if there's too much stuff.

Trim it down, use "macrophyte", not "aquarium plants".

Also, see what google books pulls up.
I have a lot of books.
I read them too.

Over time, and continuously looking, you gain a lot.

Regards,
Tom Barr

[shoggoth43]

I was recently reading someone having issues with hair algae and they referenced EI and several other methods. Accordingly he went into the CO2 and whatnot he used and how he could never quite get it under control and that the idea that once the plants get going the algae will subside wasn't the whole story. His theory was that this algae actually used large amounts of silicates and due to the high amount in his water as well as the silica sand in the tank may have been a large contributing factor for the plague.

Any thoughts on this? I haven't really had time to chase that down any further but from all appearances his efforts were a step up from the usual "EI is bunk" naysayers.

-
S