YSI EXO Total Algae Sensor
Features
- Dual channel sensor
- Measures and outputs both chlorophyll & blue-green algae
- Options for ug/L and RFU outputs
- Expedited repair and warranty service
- Lifetime technical support
- More
Image | Part# | Product Description | Price | Stock | Order | |
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![]() | 599102-01 | EXO freshwater total algae sensor (chlorophyll & phycocyanin) | Request Quote | More On The Way | ||
![]() | 599103-01 | EXO saltwater total algae sensor (chlorophyll & phycoerythrin) | Request Quote | Check Availability |


Image | Part# | Product Description | Price | Stock | Order | |
---|---|---|---|---|---|---|
![]() | FNRH125-P | 125 mg/L Rhodamine WT solution, 500mL bottle | $39.42 | More On The Way | ||
![]() | 106023-01P | FWT 25 Rhodamine WT dye, 2.5% active ingredient, 1 pint | $29.95 | 6 Available |
The YSI EXO series sondes utilize TAL-PC (total algae – phycocyanin) sensors in freshwater systems which detects chlorophyll and phycocyanin.
The total algae sensor reads chlorophyll and either phycocyanin or phycoetherin at the same time. Both chlorophyll and blue-green algae parameters have proved useful in monitoring for harmful algae blooms, so YSI decided to integrate both parameters onto the same probe.
There are a few different options for calibrating this sensor which are outlined in this guide: https://www.fondriest.com/pdf/ysi_exo_ta_manual.pdf
The EXO total algae sensor has two excitation beams. The first one (470 nm) directly excites the chlorophyll a molecule while the second one (590 nm) excites the phycocyanin accessory pigment found in blue-green algae. The sensor generates and outputs two independent data sets.
The total algae sensor is two sensors in one, which gives you more space for other parameters. It is also less sensitive to common interferences, has a faster response time, and a deeper depth rating.
The depth range is 250m for the EXO total algae sensor.
A base solution (the first dilution) will last a couple of months. The second dilution should only be used for a couple of days.
In The News
Lake Superior Algal Blooms Surprise, Highlight Need for More Monitoring
In 2012, for maybe the first time, Lake Superior got scummy. 
 
 Visitors to the Apostle Islands National Lakeshore reported algae washing up on shore around the park. 
 
 It was a marked shift for the park, made up of a portion of the Lake Superior lakeshore and nearby islands. The water surrounding the park is cold, clear and typically low in nutrients: a combination unlikely to result in algal blooms. 
 
 But, in 2012 and again in 2018 after violent storms, major algal blooms—ones observed over multiple days—washed ashore and clogged the beaches with unsightly, scummy algae. 
 
 Not the usual suspects 
 
 The algal blooms of Lake Superior are not the algal blooms of warmer, more nutrient-rich lakes like Lake Erie.
Read MoreDissecting the Algae Blooms of Montana’s “Unique Gem” the Smith River
An unusual nuisance is slowly growing into an inexplicable problem for researchers at Montana’s Department of Environmental Quality . 
 
 For the last five years, a native species of algae called Cladophora has covered large portions of the Smith River, one of the state’s most popular waterways for boating, fishing and recreating. And scientists don’t know why. 
 
 “It’s just unusual. I don’t know if it’s extreme for the state of Montana as other systems have had Cladophora problems as well. But it’s most unusual due to the lack of land use changes,” said Chace Bell, a water quality assessment specialist with the Montana DEQ.
Read MoreA Lesson in Persistence: Taking On Cyanobacteria in Florida
As we hear more and more about algal blooms of different kinds across the United States, teams of scientists are working hard to ensure that they don't become our new normal. One project in Florida is taking a multi-disciplinary approach to the problem—including genetic analysis. 
 
 The team's work is part of a full-court press in Florida recently, making a serious push to understand what is triggering more frequent blooms. Jose Lopez, Ph.D. , of Nova Southeastern University , the primary investigator on the genetic analysis portion of the project, spoke to EM about the project and his work on it. 
 
 “This is a very good project,” explains Dr. Lopez. “We're excited about it, and it's a lesson in persistence.” 
 
 Dr.
Read More