Science Buddies: "Ask an Expert"

HI! I'm doing this project for my science fair that involved small pond snails. Since I was ding a whole new project made up on my known finding sources online to use I wasn't to worried about something going wrong until I began to fill the SRC form. As I was filling the SRC form needed to fill I wondered, does Bromothymol Blue do something to animals, this is because in my project the snails would be in a water where Bormothymol Blue was mixed in. I was trying to see effects on snails or any aquatic life if they had contact the the Bromothymal BLue but ended up empty handed. I hope the experts who will see my post can help me out. Thank you and have a nice day.

Hi KFHH, its good that you're checking this.
The search I did was 'bromothymol blue toxicity'. It looks like its an irritant to mucous membranes (which snails have on their whole bodies). The severity is based on concentration. I assume you're wanting to monitor the pH of your water, or CO2 content? What is your question/hypothesis?

I'm thinking that if you try to dye the whole tank, you may need a lot of bromoblue to see a color change, and that might perturb or kill your snails. If it were me, I wouldn't risk adding it to the whole tank. At the very least its effect on the snails will be an additional variable, possibly making your results more difficult to analyze.

If you're doing pH tests, an option would be to take water samples out of the tank before adding the blue.

If you're looking at CO2, this appears to be the way to go: http://www.theaquariumwiki.com/wiki/Bromothymol_blue
So that you're monitoring only the CO2 present in the water, and not any from the air. This doesn't release the bromoblue into the water.

Let us know what your experimental plan is, and we can help you brainstorm!