What the Heck is a Mosquito Dunk?

Mosquito Dunks are little 'donuts' containing a bacteria called Bti which is toxic to mosquito larvae. The idea is to place these dunks in a shallow stagnant water body where mosquitoes lay their eggs, such as an old tire, birdbath, or even a coffee can partially filled with water. As the material in the dunk dissolves, it becomes a food source for the mosquito larvae. Over time, the Bti infects the larvae and it dies.

Effectiveness - I can personally attest that this stuff works, but it is important to remember that this is a food source. If someone tries to put a dunk in a pond that already has plenty of good muck for larvae to eat, it probably won't work very well.

Toxicity - These are safe to use around fish and wildlife (per the manufacturer). The Bti has undergone a lot of toxicity testing, and all the inert ingredients are all food grade and medical grade.

pH Meters and Calibration

ALL pH meters need to be calibrated using buffer solutions. The brand doesn't matter—you could use Oakton solutions with a Hanna meter or vice versa.

So what buffers will you need? Everyone will need a pH 7 buffer. Some of the economical meters say they have "one point calibration". In this case, all you need is the 7 buffer. For meters that have 2- or 3-point calibration you will need a 7 along with either a 4 or 10 buffer. You may need both, depending on the type of solutions you are testing. You'll want a lower range buffer (4) for solutions that are more acidic or have a low-pH range and a higher range buffer (10) for more basic solutions.