We find ourselves entering the ‘dog days’ of summer as temperatures soar and algae bloom. It is during this time of the year that those of you who are constantly on the look out for blooms should consider how a chlorophyll monitoring system could help you. Systems such as the AlgaeWatch On-Line Fluorometer have been designed to assist you in avoiding algal bloom issues by providing sensitive and accurate real-time data on the algal growth in any water body. The availability of real-time data will allow you to track diurnal changes as well as longer trends in algal biomass.

If you are involved in water resources, you will be able to witness the onset of a bloom and take appropriate action before it reaches damaging levels. Additionally, the data will enable you to make efficient use of treatment chemicals, utilize the best possible water source, investigate the potential presence of taste and odor causing species, and predict filter rates. For those of you interested in monitoring coastal areas, bays or lakes, real-time algal biomass data can provide an informative data set to an existing monitoring program, detect the potential presence of harmful algal blooms, and provide a measure of the effectivity of algal treatment. We are committed to offering you simplified solutions for difficult monitoring problems.

See the article: "Simplifying Fluorometer Calibration" for information on the products and services available from Turner Designs that will ensure you collect valid data - in the lab, or in the field. Plus, our new e-support for chlorophyll a measurements section of our web site is designed to provide the background and step-by-step instruction to transform anyone into a chlorophyll monitoring expert!

Are you interested in monitoring Cyanobacteria? We would like to hear from you, and in appreciation for your responses, we'll send you a Starbucks card for completing our cyanobacteria survey.

And of course, if you still want to speak to someone, we're here to help. For sales assistance or quotes please call our sales team at (408)212-4017 and for technical assistance please call our technical support team at (408) 212 4016. We look forward to hearing from you.

Yours truly,
Rob Ellison
Director of Sales and Marketing

P.S.
August will be the last month to take advantage of our AlgaeWatch special.

Affordable Fluorescence Solutions in the Palm of your Hand

The AquaFluor Handheld Fluorometer provides affordable fluorescence solutions for those that need a lightweight and easy-to-use fluorometer out in the field. This dual channel instrument comes in the following models:

· In Vivo Chlorophyll a & Turbidity (8000-001)
· Rhodamine WT & Turbidity (8000-002)
· Extracted Chlorophyll a & Ammonium (8000-007)

Measurements for the first two models are taken by discrete sampling with 10mm x 10mm cuvettes, while the 8000-007 model utilizes 12mm test tubes. The intuitive push button layout of the AquaFluor makes this unit very easy to use, while the rugged waterproof design makes it hard to abuse. For more detailed specifications on this instrument, please view our AquaFluor datasheet.

First introduced in 2000, our handheld fluorometers have been meeting the fluorescence needs of thousands of customers throughout the world. Universities, research institutions, and environmental consultants are among the customers that have benefited from the use of our handheld fluorometer with their research projects. A few example customers that utilize the AquaFluor Handheld Fluorometer for their research includes:

· University of Arizona - Water Resources Department(chlorophyll/turbidity)
· USGS - Menlo Park, CA - Water Resources Department (rhodamine dye/turbidity)
· Moss Landing Marine Labs (chlorophyll/turbidity)
· University of Connecticut - Marine Science Department (chlorophyll/turbidity)
· Malcolm Pirnie - Environmental Engineers (chlorophyll/turbidity)
· USGS - Tampa, FL (rhodamine dye/turbidity)
· Smithsonian Institution Marine Station (chlorophyll/turbidity)
· GE Betz (chlorophyll/turbidity)
· USGS - Ann Arbor, MI (chlorophyll/turbidity)
· University of Maryland - Horn Point Lab (chlorophyll/turbidity)
· USGS - Moundsview, MN (rhodamine dye/turbidity)
· Naval Research Laboratory - Stennis Space Center, MS (chlorophyll/turbidity)
· JC Headwaters, Inc. - Environmental Consultants(chlorophyll/turbidity)
· US EPA - Philadelphia, PA (chlorophyll/turbidity)
· University of Texas at Austin - Marine Science Department (chlorophyll/turbidity)
· USGS - Rolla, MO (chlorophyll/turbidity)
· US EPA - Port Orchard, WA (rhodamine dye/turbidity)
· Southern Ute Indian Tribe - Ignacio, CO (extracted chlorophyll/ammonium)

To learn more about how the AquaFluor can assist you with your research, please don't hesitate to contact us.

Question:
We plan to use your Model 10-AU Fluorometer to perform a mixing and dispersion study using Rhodamine WT dye at a wastewater plant that discharges into a river. What is the best way to store and retrieve the 10-AU data as we perform continuous flow through monitoring on transects in a small boat?

Answer:
The 10-AU allows you to capture data several ways. The most popular way is to use the Internal Data Logging option, if your 10-AU has this option installed. The second way is to use the Serial Data output from the 10-AU connected to a computer running a Data Acquisition (DA) program. The HyperTerminal program that is included with the Windows operating system will capture serial data, but may limit the total time data can be saved continuously in a file. Another DA software program is made by Windmill Software Ltd. and they offer some versions free of charge. For more information please visit their website. The Windmill SW can also allow the capture of GPS data to correlate position to the 10-AU readings.

The third way to collect data is to use the Analog output of the 10-AU connected to an external datalogger. Refer to Appendix 11 of the 10-AU User Manual for more details.

Simplifying Fluorometer Calibration

"How often should I calibrate my fluorometer?"
"How can I tell if my fluorometer needs re-calibrating?"

Turner Designs has significantly simplified the calibration process as well as the process of validating whether a re-calibration is required. To determine if a calibration is required, Turner Designs has developed a series of secondary standards. Use of these standards eliminates the need for primary standards (a pure solution that has a known concentration) since, once a relationship is established, the solid standard simulates a concentration of the primary fluorophore being measured.

This secondary standard is much simpler to use because it has the advantage of being instantly ready for use, and it is easy to transport and store. Plus it is essentially independent of other environmental variables such as temperature. However, it is a secondary standard because it is not of the same substance as is being measured, (normally chlorophyll, or a tracer dye), and can only be used in place of a primary standard if it has previously been correlated with a primary standard.

Turner Designs also sells Primary Standards for calibrating fluorometers when making extracted chlorophyll measurements. With the emphasis again on ease of use, the liquid Chlorophyll standard is supplied in an ampule ready to use, and comes with a certified concentration, and certificate of analysis.

When performing in-vivo sampling, using Solid Secondary standards is the most logical approach for calibrating. Then when you extract samples you will determine the correlation of the Secondary Solid standard for a given "in-vivo" Chlor a concentration, visit our website for more details.

Likewise, when you perform extracted chlorophyll analysis, initially you will calibrate with a Primary Standard in the appropriate solvent, and at that point will determine the correlation of the Solid Secondary standard on a freshly calibrated instrument.

This gives you the convenience and cost savings of using the Solid Secondary standard on a routine basis for doing your Calibrations for both the in-vivo and extracted Chlor measurements, so that you can calibrate for either situation quickly and repeatedly.

To obtain further information on Turner Designs Primary and Secondary Standards please visit our website, or email our support team.

St. Anthony Falls Laboratory Utilizes 10AU & SCUFA for Hydraulic Experiments

The St. Anthony Falls Laboratory (SAFL) is a teaching and research facility of the Department of Civil Engineering, University of Minnesota. Their goal is to advance the knowledge and understanding of environmental hydraulics, turbulence, earthscape evolution, and climate/ecosystem dynamics via high quality experimental, theoretical and computational research. As a group, they are committed to transferring that knowledge to the engineering community and to the public through applied research and outreach activities.

Ben Erickson is one of the scientists at SAFL, and is considered the "fluorometer guru" of the laboratory due to his extensive experience with the Turner Designs line of fluorometers. Ben and his colleagues utilize the 10AU and SCUFA fluorometers to conduct hydraulic experiments using rhodamine WT dye as a fluorescent tracer. The information learned in their dye tracing experiments is then applied to solving real life hydraulic issues.

One of the recent issues that the SAFL is currently working on is the feasibility of an emergency sewage storage system for overflows caused by above average amounts of rain runoff in an urban location. To investigate the feasibility, Ben and his team conducted experiments on a smaller scale system that resembled the location under investigation. The key questions that required the use of our fluorometers was how to best set up an aeration system for sewage treatment. The fluorometers were used to quantify diffusion and dispersion in and around a deep bubble column.

To investigate the aeration set-up, the SAFL placed submersible aerators at strategically placed locations on the bottom of the experimental water system. Slugs of rhodamine WT tracer dye were then released at the bottom of the system, while the 10AU and SCUFA Fluorometers monitored its concentration at various points in the water column. With the data from multiple trials, estimates were made on the rate that a bubble column would entrain the surrounding water.

To address the gas exchange questions, the experiment took the data from the previous entrainment experiments and decided on a reasonable flow rate to inject of the test solution. Known flow rates of the conservative tracer rhodamine WT and a volatile tracer were then added at the bottom of the water column. Once at a steady state, water samples were collected and analyzed utilizing fluorometers and gas chromatography yielded data indicating how much tracer gas escaped from solution into gas. The flourometers were used both in the final analysis and during the course of the experiments. They proved quite valuable by allowing the researchers to look at the real time data as the experiment progressed.

With the amount of useful data generated from these experiments and the fluorometers, Ben considers the research project to be an overall success. This information will soon be transferred to the engineering community to enable them to make sound decisions on the emergency sewage storage system project. To learn more about the exciting research that goes on at SAFL, please be sure to visit their website.

Technically Speaking, It All Adds Up...
is a series of articles for people who want to obtain the best possible results from their fluorometer. Last month Technically Speaking described how to improve measurement repeatability by determining and implementing a cleaning schedule for the sample cell.. This month's article will describe how ambient light affects fluorescence when measuring in vivo chlorophyll, and how to compensate for it.

Effect of Light on in vivo Chlorophyll Fluorescence
Light history, (the amount and type of light environment of a particular environment preceding an in vivo fluorescence measurement), can have significant effects on the fluorescence in living algal cells. At low light levels, algal cells can optimize the light uptake by pushing chloroplasts to the outer edge of the cell and/or by producing more chlorophyll per cell. At high light levels ,near the surface, non-photochemical quenching can result in a decrease in fluorescence. Both of these responses can alter the in vivo fluorescence signal without a corresponding change in the algal biomass.

In Figure 1, the bottom of the photic zone (lit zone of the ocean) is characterized by very low light levels. This results in a lower level of fluorescence due to low algal biomass. However, the fluorescence:biomass ratio may be higher in the darker zones due to the cells acclimation to the ambient light field.	Figure 1
In Figure 2, higher in the photic zone the cell growth is still inhibited by lower than optimal light but fluorescence:biomass may remain high and algal biomass is increasing.	Figure 2
Figure 3 depicts an optimal environment for growth with sufficient levels of light and nutrients. In vivo fluorescence will most accurately measure algal biomass in this environment due to the lack of low or high light effects on fluorescence.	Figure 3
Figure 4: Near the surface with high levels of solar radiation, non-photochemical quenching can often inhibit the fluorescence. This phenomenon occurs when there is too much light for the algal cells to process. This state causes a decrease (quenching) of the fluorescent signal that is un-related to the photosynthetic rate or algal biomass.	Figure 4

Two steps that can be taken to avoid false chlorophyll readings are:
· Conduct profiles at night
· When using a flow-through fluorometer, use an opaque hose when sampling natural waters. (The transport time of the water in the hose will dark adapt cells to an extent, reducing light history effects).

For more information on environmental factors that can impact in vivo chlorophyll measurements, please visit the Turner Designs e-support pages.

Next month's article will explain why the Calibration Solution reading may change immediately after calibrating the fluorometer.