Barley as an Algae Remover
- Re: "H" and the Peat solution
by brendafw/gte.net (Tue, 27 Jun 2000)
- Barley Straw
by "Dixon, Steven T. (BEn)" <stdixon/ben.bechtel.com> (Wed, 28 Jun 2000)
- Barley Straw
by brendafw/gte.net (Thu, 29 Jun 2000)
- Steve's Barley Straw experiment.
by IDMiamiBob/aol.com (Thu, 29 Jun 2000)
by "Thomas Barr" <tcbiii/earthlink.net> (Thu, 29 Jun 2000)
- Barley Straw revisited
by mickey/singnet.com.sg (Mon, 07 Aug 2000)
- Re: Re: Barley Sraw Revisited
by "Robert H" <robertpaulh/earthlink.net> (Tue, 8 Aug 2000)
- Fermented Barley Straw, Take 2...... (long)
by "James Purchase" <jpurch/interlog.com> (Thu, 6 Jul 2000)
- algae, H2O2, SOD, et al.
by George Booth <booth/lvld.agilent.com> (Mon, 10 Jul 2000)
- New email
by Thomas Barr <tcbiii/yahoo.com> (Sat, 12 Aug 2000)
Date: Tue, 27 Jun 2000
| Neil wrote:
| As far as I know, peat is not known to release chemicals which inhibit
| algae... so it is different than decaying straw. Peat can lower pH which
| can change the the conditions favoring certain microscopic flora and will
| encourage many vascular plants to grow which in turn can make life
| difficult for algae. Peat can also stain the water, at least temporarily.
and Wayne wrote:
| I read an article on this which appeared to be quite professionally
| and of course I can't seem to find it right now. I believe their thinking
| was that the action of sunlight alters humic acids released to form
| compounds that inhibit the growth of algae. So, I don't see why barley
| is not the same as peat in this regard except that the lighting in an
| aquarium is not usually as strong as sunlight.
I decided to look up the original article that explains how the barley straw
works and according to the article Wayne is correct. Decaying barley straw
releases humic acids which then react with sunlight to release hydrogen
peroxide which inhibits the new growth of algae. Here's a link to the
article which describes it much better than I can.
Hope this helps.
Watergardening in the Desert!
by "Dixon, Steven T. (BEn)" <stdixon/ben.bechtel.com>
Date: Wed, 28 Jun 2000
The recent APD references to barley straw, humic acid, and algae reduction
reminded me that I intended to report some time ago on my anecdotal
experiments with barley straw. I purchased about a cubic foot of barley
straw from one of the pond supply houses soon after the first report on the
APD that barley straw was used by pond enthusiasts to reduce algae.
I put about 2 handfuls of straw in a filter bag for a Eheim 2217 canister
filter used on a 125 gallon tank and about 1 handful of straw in a filter
bag for a Eheim 2213 canister filter used on a 40 gallon tank. In both
cases after about 3 months the barley straw had disappeared completely and I
placed new straw in the canister.
By and large I didn't change any of the other tank parameters-lighting,
water changes, fertilization regime, etc. I noticed no changes in the
presence of algae in either of my tanks during the test period. Neither
tank had a significant algae problem, but both had occasional spot algae on
the glass and some algae on older plant leaves which continued during the
period in which barley straw was used in the canister filters. The 40
gallon tank had and continues to have a slight problem with filamentous
algae. The use of barley straw appeared to have no effect on the algae
grown in these tanks.
Anyone else tried using barely straw to reduce algae?
Regards, Steve Dixon in San Francisco
Date: Thu, 29 Jun 2000
Steve Dixon in San Francisco wrote:
| I put about 2 handfuls of straw in a filter bag for a Eheim 2217 canister
| filter used on a 125 gallon tank and about 1 handful of straw in a filter
| bag for a Eheim 2213 canister filter used on a 40 gallon tank. In both
| cases after about 3 months the barley straw had disappeared completely and
| placed new straw in the canister.
| By and large I didn't change any of the other tank parameters-lighting,
| water changes, fertilization regime, etc. I noticed no changes in the
| presence of algae in either of my tanks during the test period. Neither
| tank had a significant algae problem, but both had occasional spot algae
| the glass and some algae on older plant leaves which continued during the
| period in which barley straw was used in the canister filters. The 40
| gallon tank had and continues to have a slight problem with filamentous
| algae. The use of barley straw appeared to have no effect on the algae
| grown in these tanks.
| Anyone else tried using barely straw to reduce algae?
The barley straw did work well in reducing string algae in my pond. Others
have said it didn't work for them. I think there are certain requirements to
make it effective. Such as: placing the straw near the top of the water near
or at the point where the water reenters the pond after being filtered. The
decaying straw also needs sunlight and oxygen to work effectively. I also
believe it may or may not work depending on other water parameters. There
are so many variables in different water environments that I'd be pretty
amazed if any solution worked for everyone. Barley straw is just one
possible solution that may work if conditions are right.
There are also other possible solutions like "managing nutrients to control
algae" that is explained in this article:
as well as here:
Keep in mind that any solution one tries can also be detrimental, so always
proceed carefully with anything you try unless you don't mind the
possibility that all your fish, plants, other creatures may be affected and
you may even have to start all over again from scratch.
Watergardening in the Desert!
Date: Thu, 29 Jun 2000
Unfortunately, Steve, the barley straw trick reequires bright sunlight to
break the humics from the straw down into algicidal by-products. We didn't
get that piece of the puzzle until a couple days ago.
by "Thomas Barr" <tcbiii/earthlink.net>
Date: Thu, 29 Jun 2000
>>Anyone else tried using barely straw to reduce algae?
>Unfortunately, Steve, the barley straw trick reequires bright sunlight to
>break the humics from the straw down into algicidal by-products. We didn't
>get that piece of the puzzle until a couple days ago.
So we could isolate/concentrate the chemical by putting the mix of Barley
and water outside in sunlight in a tub? Or does the chemical(s) break down
too fast, evaporate etc? Would adding UV light at a low level do the
breaking down for us perhaps? What specific chemicals were they mentioning?
Inquiring minds want to know.
Also would adding a UV to the set up break the bonds since the humic I would
assume leach out slowly into the water and these humics would pass through a
UV sterilizer thereby breaking the bonds like sunlight might? What component
of sunlight does this breaking also?
Date: Mon, 07 Aug 2000
I have lurking for over two years now and so I thought that I should
finally contribute something to the list. This is the first time I am
posting, so be nice.
The previous mails regarding barley straw has lead me to believe that the
algae control by barley straw was largely due to the release of hydrogen
peroxide and super oxide radicals, under aerobic conditions with bright
light. After that, we see many people dumping hydrogen peroxide into their
Since then, someone directed me to this paper by N.C. Everall and D.R.
Lees, 1997 (The Identification and Significance of Chemicals Released from
Decomposing Barley Straw During Reservoir Algae Control, Wat. Res., Vol 31,
No3, pp 614-620) and it suggests that the anti-algae properties of barley
straw was attributed to a cocktail of phenolic compounds which are of known
phytoplankton toxicity, and some, are toxic to higher plants. This also
includes some unknown chemicals that are yet to be identified. He goes on
to described lignin as a promising source of "anti-algal precursory
oxidized phenolics" and suggested that you could use other alternatives (he
cited anti-algal studies done on oak leaves). Also, "Phototransformation of
phenolics results in the biproduction of potentially phytotoxic hydrogen
peroxide and super oxide radicals".
In an earlier paper by the same person, he stated that barley straw was
used because of a low phosphorous content.
Addressing the issue of Dulpa and their fermenting straw in dark reactor:
Since the anti-algal properties are due to phenolic that solubilize from
barley straw, it doesn't really matter what material the reactor is made
of. Dupla used dark plastic because decomposing barley straw is probably
not a pretty sight in a well- planted Dutch tank. In anyway, I suppose you
can throw a bale of barley straw in your sump and have the same effect as
Also, since the paper that I've cited is dated 1997, I was wondering if
anyone else to update on this.
by "Robert H" <robertpaulh/earthlink.net>
Date: Tue, 8 Aug 2000
> the straw began to break down 2weeks after. As the straw decomposed,
> so there was a lifting of the algae. It is now day 29 of that tank
> and it is almost "photo-clear" of algae. The exception is that
With such a strong effect on algae, is there any possiblity that it would
inhibit growth of higher plants as well? <<
I found a detailed scientific study on the use of Barley and it says the
1 Effects on other aquatic plants. No direct effect of straw on aquatic
vascular plants has been found in either laboratory or field experiments.
However, in several trials where straw has successfully controlled algae,
there has been a noticeable increase in the growth of submerged vascular
plants. It is likely that this is a result of the loss of competition from
the algae which has allowed the vascular plants to recolonise water in which
previously they were unable to compete with the algae. In some instances,
the recovery of the vascular plants has been so marked that they, in turn,
caused problems to water users and also required some form of management.
However, they are generally easier to control and less troublesome than the
algae and so are more acceptable in most waters. In some instances the
recovery of the vascular plants has been so strong that they replaced the
algal growth as the dominant plant form so that subsequent treatment with
straw was no longer needed.
Dr Jonathan Newman
Senior Research Scientist
IACR Centre for Aquatic Plant Management
Broadmoor Lane, Sonning,
Reading, Berkshire, RG4 0TH, UK
You can find the full article at http://www.execpc.com/~aqsys/barley.html
and soon on my WEB site.
Robert Paul H
by "James Purchase" <jpurch/interlog.com>
Date: Thu, 6 Jul 2000
Tony's question regarding "fermented" straw caused me to do a little
surfing..... and I found some interesting things......while what follows
contains "speculation" on my part, the material I am quoting from seems to
be based on sound scientific research.... hope that doesn't bother too many
people..... <g> I've given the URL's for reference, should anyone care to
readd the full articles.
Extract from WWW
Microbial growth, oxygen and warm water temperatures activate the
decomposition of the straw. With sufficient water flow through the straw ,
lignins oxidize into homic acids and, with sunlight and oxygen, destroy
algae, with nodetrimental effects on higher plant and aquatic life.
How this controlling of algae by the decomposing straw isn't understood. The
straw needs to decompose in water while oxygen is available. It seems that
the chemicals released by the decomposing barley kills or inhibits the
growth of the algae.
Furthermore, the microbes involved in decomposition consume or compete with
algae and cyanobacteria. If oxygen becomes limited, many of the microbes
causing the breakdown of the barley straw are killed. Therefore, the straw
needs to be placed in shallow water, in a current or floated near the
Barley straw decomposes slowly so its oxygen demand does not cause problems
unless an excessive amount of straw is used. Stagnant water will go
anaerobic (without air) inside the straw bundle killing the microbes. Also,
too much straw can deoxygenate the water. It is best if the straw is applied
loose so that water can move freely through it. The more points that the
barley straw extract can emanate from, the better the control.
My comments: Is sunlight necessary for lignins to oxidize into homic
(humic???) acids, or is the common caution that the barley straw needs to be
close to the water surface only due to the increased availability of Oxygen
in surface waters? In the Dupla reactor, which appears to be dark plastic, I
can't understand how light enters into this process or if it is necessary.
Extract from Pond Algae and Its Control by Andrew Spear, Birdies' Backyard
A relatively recent algae control is barley straw. The use of straw to
prevent algae has been known for hundreds of years, but recent research by
the Center for Aquatic Plant Management in Berkshire, UK, has discovered the
means for its effectiveness. One-half pound of straw, loosely confined and
placed in moving water will control algae for up to a year in a 1000 gallon
pond. It takes 6 to 8 weeks for the straw to start working. As the barley
straw slowly decomposes, it releases a natural algaecide and provides a
source of food for your fish. This method will not kill already grown algae
cells, but it will keep new algae from growing. It will not, however, reduce
the cause, which is a buildup of nutrients. An ultraviolet light can be used
to control algae blooms. If properly sized and the proper flow rate is
achieved to provide a UV irradiation of at least 30,000 micro-watt seconds
per square centimeter, algae cells that pass through the UV light will be
killed. For optimum control, the light should be placed after the mechanical
filter but before the biological filter since cloudy or dirty water will
reduce the effectiveness and the UV light will kill your good bacteria. If
you only have one filter (a combination mechanical and biological), best
placement of the light would be after the filter for maximum effect. UV
light bulbs need to be replaced at least every year if used continuously as
they darken with age and reduce the available light output. Make sure you
read the manufacturer's literature and ratings to get the right unit for
your size pond and pump flow rate. Again, this method will not reduce the
available nutrients, but may prevent the buildup of algae in the spring
until your plants have entered their rapid growth state.
My comments: I notice that they say that it will have NO EFFECT on algae
already present, and also backs up Tom Barr's comments about balance and
proper aquarium managment. High fish loads and/or heavy feeding can prevent
you from ever being able to control an algae problem. The possible use of UV
light is interesting (for the technically inclined and equipment junkies)
with the usual warning that it will also kill any other water born organisms
Extract from Control of Algae With Straw [IARC Information Sheet 3]
When barley straw is put into water, it starts to rot and during this
process a chemical is released which inhibits the growth of algae. Rotting
is a microbial process and is temperature dependent, being faster in summer
than in winter. As a rough guide, it may take 6-8 weeks for straw to become
active when water temperatures are below 10 degrees C but only 1-2 weeks
when the water is above 20 degrees C. During this period, algal growth will
continue unchecked. Once the straw has started to release the chemical it
will remain active until it has almost completely decomposed.
Although the exact mechanism by which straw controls algae has not been
fully proven we believe that the process may occur as follows. When straw
rots, chemicals in the cell walls decompose at different rates. Lignins are
very persistent and are likely to remain and be released into the water as
the other components decay. If there is plenty of oxygen available in the
water, lignins can be oxidised to humic acids and other humic substances.
These humic substances occur naturally in many waters and it has been shown
that, when sunlight shines onto water which contains dissolved oxygen, in
the presence of humic substances, hydrogen peroxide is formed. Low levels of
peroxide are known to inhibit the growth of algae and experiments have shown
that sustained low concentrations of hydrogen peroxide can have a very
similar effect on algae to that of straw. Peroxides are very reactive
molecules and will only last in water for a short time. However, when humic
substances are present, peroxides will be continuously generated whenever
there is sufficient sunlight. The slow decomposition of the straw ensures
that humic substances are always present to catalyse this reaction.
The chemical released by the straw does not kill algal cells already present
but it prevents the growth of new algal cells. Thus algae which die will not
be replaced when the straw is present and so the algal problem is
Activity is only produced if the straw is rotting under well oxygenated
The chemical does not appear to have any effect on higher plants.
There are no reports of harmful effects on invertebrates or fish except in a
few instances where excessive amounts of straw were applied to small ponds
and the water became deoxygenated.
My comments: H2O2 rears its head! Again, I wonder if sunlight (or other high
intensity light source) is required in this conversion, or is a high level
of Oxygen all that is required? Additionally, it doesn't seem to have been
discovered or decided if it is the H2O2 which is the "active ingredient"
here, but it does seem to point out the fact that the effect of H2O2 is the
same as the straw. And since it is the end result (supression of algae)
which seems to be the important thing, it might not matter - especially as
it is easier to dose a small quantity of H2O2 that it is to fiddle with a
mass of rotting straw.
But PLEASE, don't ANYBODY take this as a recommendation from me to pour a
cup of full strength H2O2 into your aquarium!!! Maybe it's time for me to
pull out an empty tank and innoculate it with algae and play around.....
by George Booth <booth/lvld.agilent.com>
Date: Mon, 10 Jul 2000
Karla had a slow morning, so she wrote up a few more thoughts regarding the H2O2 and barley straw discussion.
I won't even *try* to translate this into something common folk like me can
understand, other than to note that SOD stands for "superoxide dismutase".
You realize it has been 9 years since I did this stuff . . .
Superoxide is O2 with a full negative charge and an extra electron so it is
deisgnated as O2- with a dot above the -.
There are other oxygen free radicals such as hydroxyl radical (.OH). Damage
from free radicals is the current rage in anti-aging vitamins and
supplements to fight free radicals - vit C, vit E, selenium. People feel
that by protecting from free radicals they will protect organs from aging. -
There are some prokaryotes that do not have SOD available and thus are
susceptible to damage by superoxide, e.g. fungus. That is what allows your
white blood cell respiratory burst to produce superoxide, hydrogen peroxide
and ultimately HOCl to kill off infectious agents and not hurt you too
badly. We have catalase and SOD to protect us from hydrogen peroxide and
superoxide but the white blood cells do eventually succomb and form the pus
that is evident in infection.
Since the rotting of the straw prevents algae from developing, but doesn't
affect the growth of fish or higher plants, I figured that algae must lack
the protective mechanisms against oxyradicals such as catalase and SOD found
in higher organisms. Since I don't know plant physiology, I do not know
what enzymes algae may have for defending against oxyradicals.
If you want to start some more chatting you might bring up the subject of
reactive nitrogen species which have been shown to cause damage to cells.
In fact recently nitric oxide has been shown to cause some of the biological
effects that were originally credited to oxyradicals. Rotting straw could
certainly generate some of those from nitrogenous waste.
Karla Booth in Ft. Collins, Colorado (email@example.com)
by Thomas Barr <tcbiii/yahoo.com>
Date: Sat, 12 Aug 2000
Well, after much a do with an evil Mac update, I have
a new address for all those interested. If folks could
kindly update this new address on their list that
would be much appreciated since I know a fair number
of yens out dar.
Regarding straw etc et al.
Some folks are testing the straw mix in a bottle out
here in SF as we speak and some folks that have used
the straw in the past. Personally, I'm very skeptical.
Nothing can be substituted for gardening/pruning/good
nutrients/CO2 and lighting. A magic bullet, snake oils
and other one shot cure alls will not *ever* make up
for this. These types of product prey on the new and
frustrated plant keepers. This part bugs me. It
confuses and blinds the real issues to be learned by
the new person interested in plants and keeping them
The theory and why etc intrigues me. This part is
interesting to me. Many of us over many years on this
list have tried all kinds of stuff to help our tanks.
Each time it always comes back to the basics of
balance and management. Sure, a neat little trick here
and there surface but not enough to make too much of a
big deal over except as a quick cure,
sanitization(bleach,H2o2, ionic copper etc).
I think it should be noted that as far as I have
understood and read about this topic, it is green
water and hair algae that the straw effects, not the
other types of algae. There are many other ways that
can be used to get rid of both these algae.
Shrimps are very good at ridding hair algae. Manual
harassment, although laborious, does quite a lot of
damage especially combined with water changes
afterwards. Building the nutrients back up each time
you do a water change to their proper levels keeps the
tank in line and makes it very hard on the algae.
I remove, attack and scrape from the glass any algae
first -then do the water change.
Keep doing this and it will work for almost all types