KH is important!
KH or carbonate hardness can be critical to the overall health of your trout. It's one of the most important compounds to measure, even before you get your eggs. Adequately high KH will be good for your trout's slime coat and will result in more stable pH. In low-KH tanks, pH can vary erratically, which will be very stressful for your fish. Here's an article from Maryland TIC coordinator Chuck Dinkel on the relationship between pH, KH, and GH. Check it out!
The geological conditions through which your school's water travels--the bedrock under your feet--greatly influence your tank's KH. Many of the schools in my area, the southwestern part of Vermont, sit on lots of limestone and marble. Think Proctor, West Rutland, and Dorset, all famous for their marble quarries. The presence of these calcium-rich rocks in the ground below our schools produces ridiculously high KH. Some of our schools will get KH readings of 250 or higher. Unusual, but not a problem. But in other parts of the state, extremely hard rocks (with little calcium) can produce water with low KH levels. That's something we need to address.
I've pasted below an image that shows the distribution of various types of bedrock across the state. You can access this image and others at this Agency of Natural Resources Web site http://dec.vermont.gov/geological-survey/publication-gis/VTrock. Ask your students to figure out what kind of rock your school is sitting on.
Soon after you've filled your tank, you should test the water for KH. If it is not at least 150, follow the instructions on page 78 of the Vermont TIC Manual for raising it.
Every year we try to use the experiences of Vermont schools to improve our methods and procedures. We can improve our processes only if teachers and their students keep good data. There are two Excel spreadsheets we want you to complete. The first page of one, the "Temp and DI record and swim-up calculator," looks like this.
Read the Instructions.
If you don't see four tabs at the bottom, you should go to the View menu and choose the Enter Full Screen command. You'll need access to Tab B and probably also to Tab C. (We'll discuss that in the next blog post.)
Once you can see the tabs, click on Tab B. "Temp. entry & DI record." Here's what that worksheet looks like.
On the day your eggs arrive, you should enter "Arrival Date" and "Developmental Index (DI) on arrival." Then enter the temperature of your tank in the yellow column (next to the correct date). Keep this chart up by entering temperature for every day, including days when you're not around to read the temperature. For those days, estimate or, worst case, guess! Once all your fish are swimming up, you can stop entering data into this spreadsheet.
The other Excel spreadsheet, Template for TIC data entry, looks like this.
You should enter data into this spreadsheet right up until the time you release your fish. As you will see (rightmost column), you should also use this spreadsheet to record observations, for example:
At the end of the TIC season, I will ask you to send me both of these completed spreadsheets. Once I've compiled the submissions from all of our schools, the other coordinators and I will pour over them, looking for patterns, relationships, and insights. Our discussion of these data will play a large role in the recommendations we make to teachers next year.
My friend Chuck Dinkel also provided this extensive list of all the TIC tasks you can perform with your baster:
I've compiled below a partial list of lessons we've learned--sometimes the hard way--from our past years of TIC experience. If you remember these and take appropriate precautions, you'll increase your chances of a successful year.
Next week I'll publish one more pre-break blog, this one focused on what temperature to keep your tank at prior to the swim-up stage.
Joe Mark is Lead Facilitator of Vermont's Trout in the Classroom program.
In June 2012, I retired after 40 years in higher education, having spent the last 32 years of my career as dean at Castleton. One of the first things I volunteered to do in retirement was to work with a parent-friend to help the Dorset School, where his kids and my Vermont grandkids attend, start a TIC program. Gradually that commitment grew into my current role, which is both demanding and highly rewarding.