Revenge of the Algae

It’s day three of the algae treatment of my pond. The data are not that encouraging if you were rooting for algaecide as a quick fix for my swampy green problem. Here are the results:

Visible spectra of pond water over 3 days

The absorption spectrum looks fairly consistent over the three days. We have had temperature fluctuations of about 10-15 degrees in addition to rain, so there are many variables that can impact subtle variations in the shape of the spectrum. The water has not altered from its turbid, green characteristics, and the spectra support the claim that little has changed in terms of algae content.

Fluorescence spectra (excitation wavelength of 405 nm) of pond water over 3 days. The spectra have been normalized by setting the height of the peak at 405 nm to 1.

The fluorescence spectra are displayed slightly differently from the previous articles in that they have been normalized. Assuming that the excitation peak stays roughly the same regardless of conditions, normalizing the spectra allows for a better comparison of the peak at 690 nm. It looks like there was a big change between days 1 and 2; however there is little change, and possibly an increase, in the peak from day 2 to day 3.

The instructions on the algaecide bottle say to repeat the treatment every 3 days until the pond has cleared. I will do one more treatment of 15 mL and if I do not see any meaningful change in the water quality, I will bite the bullet and replace the water.

Black Lives Matter

The first 12 years of my professional life were spent at Chicago State University, a primarily minority serving undergraduate institution located in South Side Chicago. I remember very clearly my interview with the faculty, often being asked how I (a white guy) could contribute to the successful education of young black scientists.

Having grown up in a very monolithic community, the only honest answer I could give was to state that I was open to guidance, willing to learn and committed to doing what it takes to promote student success.

I experienced many joys when students became the first graduates of their families; I experienced great sorrow mourning the loss of students who were victims of gang violence. My students and I continued to challenge one another, learn from one another and become better because of one another.

I feel sorry for racists who do not value diversity. Their ignorance puts them at a disadvantage and makes them weak. It closes doors to them that would lead to remarkable experiences and growth.

The students of Chicago State opened my eyes and mind in ways that I still find difficult to express because they still impact me three years after leaving the college for another school. I consider myself fortunate to have had the opportunity to teach chemistry to the future black leaders of our field and to learn about learning in an environment very different from what I had known.

This is why Black Lives Matter to me, and why I stand by those who continue to fight against the injustice and inequality that should have been left behind in the last millennium.

Attack of the Algae Part 2

Yesterday I started an algae control protocol for my garden pond and decided to monitor the progress with spectroscopy. I’m simply measuring the absorbance and fluorescence (405 nm excitation) of the pond water using a Vernier Spectravis spectrophotometer. Here are the results, compared with yesterday’s spectra.

Fluorescence spectra (ex. 405 nm) of garden pond water following treatment of the pond with algaecide.
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Killing two problems with one spectrometer

I’ve got two problems. First, my ornamental garden pond is filled with algae. In the past, I have simply emptied it out and refilled, but I’m tired of doing that, and I also suspect there are some tadpoles growing in the pond and I’d like to let them do their thing, if possible.

Second, COVID has shut down summer research at my school, and I’m in need of a science project to keep my mind in the game. Since I work mostly with instrumentation design, I brought much of my lab home with me during the transition to on-line learning this semester. One of the instruments I brought back was a Vernier Labquest with the SpectroVis Plus spectrophotometer/fluorimeter.

With most of New York having recently entered Phase II of our return to normal – whatever normal will look like – my wife and I have been spending our stimulus checks at the local garden supply store. One of their products is an algaecide that “works fast”. That got me thinking; I don’t know “fast” means in the algaecide’s promotional language, but I need to clean up this pond and I can use the spectrometer to help me measure how fast is fast.

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3DP Point group set

I’ve been working on a set of 3D printed molecules for studying point groups. The set below contains 12 molecules that represent some of the point groups commonly taught in undergraduate inorganic chemistry classes. The structures are made using Mathematica’s curated data sets and a few molecules pulled from other sources. I split the set into two series for printing, each taking about 3 h to print.