<h4><u>Safety</u></h4>
<ul>
<li>Never drink the water used in this experiment!</li>
<li>Wash your hands after the process.</li>
<li>Gloves are optional but encouraged.</li>
</ul>
<p></p>
<p style="color: rgb(170, 170, 170); font-style: italic;"><cite>Photo by <a href="https://unsplash.com/@diana_pole?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Diana Polekhina</a> on <a href="https://unsplash.com/photos/z2SRfgmV1ZY?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Unsplash</a></cite></p>
<hr />
<h4><u>Preparation Instructions</u></h4>
<ul>
<li>Watch the videos we created for use of the Classbox throughout this lesson! </li>
<li>Label and separate filtration items. Place them on a table for easy access.</li>
<li>Obtain 1-2 water container bags of freshwater from a local river, stream, reservoir, or tap. There are 2 types of containers provided in the Classbox to be used at your choice. Alternatively, use a bucket on hand. </li>
<li><u>Optional</u>: obtain pollutant sources and distribute in provided plastic cups (making sure to leave at least 1 cup for each group) like <em>dirt, soil, soap detergent, open tea bags, food scraps, glitter, etc</em>. Label these so students know what pollutants they are putting into their own polluted water samples.</li>
<li>To avoid dark water that is filtered through, avoid coffee grounds and food coloring. Also, you may rinse activated charcoal and sand in water <em>before </em>starting the activity, otherwise the filtered water may come out dark the first few times.</li>
<li>Activated charcoal can stain hands and clothes temporarily. Wash out with warm water and soap.</li>
</ul>
<p><em>Click below to watch a video overview the lesson!</em></p>
<div style="padding:56.25% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://player.vimeo.com/video/739648667?h=43ace04897&badge=0&autopause=0&player_id=0&app_id=58479" style="position:absolute;top:0;left:0;width:100%;height:100%;" title="Water Filtration and Testing Classbox Video"></iframe></div>
<script src="https://player.vimeo.com/api/player.js"></script>
<hr />
<h4><u><strong>Performing the Chemical Strips Test Instructions</strong></u></h4>
<p><em>Watch the quick instructions video and read the instructions below!</em></p>
<div style="padding:54.79% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://player.vimeo.com/video/718780576?h=3bc69c5200&badge=0&autopause=0&player_id=0&app_id=58479" style="position:absolute;top:0;left:0;width:100%;height:100%;" title="Chemical strip testing"></iframe></div>
<script src="https://player.vimeo.com/api/player.js"></script>
<p> </p>
<ol>
<li>Take off the cap, press the “on” button and the “clear” button. </li>
<li>Submerge the sensor tip into your water and hold until the number on the meter stops moving. Press “on” again and take out the meter to read. The number shown indicates the amount of total dissolved solids using parts per million, or ppm. </li>
<li>To record <strong>salinity</strong>, press the “mode” button once and obtain the electrical conductivity reading in microsiemens per centimeter, or μS/cm.</li>
<li>Use the <i>TDS and Salinity Record Chart</i> on your <em>lab worksheet</em></a> to record your results and compare them to the <strong>EPA’s</strong> Recommended Range for Drinking Water.</li>
</ol>
<p> </p>
<hr />
<p> </p>
<h4><u><strong>Performing the TDS and Salinity Test</strong></u></h4>
<p><em>Watch the instructional video or read the instructions below.</em></p>
<div style="padding:54.79% 0 0 0;position:relative;"><iframe allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" frameborder="0" src="https://player.vimeo.com/video/718809398?h=44351f6a81&badge=0&autopause=0&player_id=0&app_id=58479" style="position:absolute;top:0;left:0;width:100%;height:100%;" title="iCloud Photos (1)"></iframe></div>
<script src="https://player.vimeo.com/api/player.js"></script>
<p> </p>
<ol>
<li>Obtain one strip and immerse the entire strip in water for 2-4 seconds and take out immediately. </li>
<li>Use a clean paper towel to absorb the excess water by holding one edge of the strip on the paper towel. </li>
<li>Hold the strip horizontally for 30 seconds and compare results against the color chart provided. </li>
<li>Check the final result within 30-50 seconds. It may be helpful to take a picture of the strip to use for later.</li>
<li>Use the <em>Chemicals Test Record Chart</em> to record and track your results on the <em>lab worksheet</em>. </li>
</ol>
<p> </p>
<hr />
<h4><u><strong>Vocabulary</strong></u></h4>
<ul>
<li><b>Filtration</b>: The process of removing solid particles from a liquid using a filter medium</li>
<li><b>Pollution</b>: harmful substances introduced into the environment</li>
<li><b>Quantitative data</b>: Countable or measurable data, relating to numbers</li>
<li><b>Qualitative data</b>: Descriptive data, relating to words or language</li>
<li><b>Turbidity</b>: Cloudiness or haziness of a fluid caused by numbers of individual particles. </li>
<li><strong>Total Dissolved Solids (TDS): A</strong> measure of anything dissolved in water that is not a water molecule <em>(minerals, metals, organic materials, etc)</em>.</li>
<li><strong>Salinity: </strong>The saltiness or amount of salt dissolved in a body of water. It is measured by electrical conductivity.</li>
<li><strong>Electrical Conductivity (EC):</strong> Measures the ability of a liquid to carry an electric charge. The higher the EC, the more salt is dissolved in water.</li>
<li><strong>Hardness: </strong>A measure of the amount of calcium and magnesium salts in water.</li>
<li><strong>pH: </strong>A measure of how acidic/basic water is. The range goes from 0 – 14, with 7 being neutral. Most water for use has a pH of somewhere between 6.5 and 8.5.</li>
<li><strong>EPA: </strong>Stands for Environmental Protection Agency, a federal government agency whose mission is to protect human and environmental health.</li>
</ul>
