Science Buddies: "Ask an Expert"

:in my science fair project, I am seeing what way removes algae the most efficient way. First I make algae in 4 containers,then I put the 4 different ways which are put algae eaters, plants , keep away from light, and take 10% water out every day. What can I do to improve this project.

Hi,

This sounds like a really interesting project. The main thing I would say to make sure your project is really strong is to make sure you are including all of your necessary controls. In addition to your 4 experimental settings (alas eaters, plants, darkness, and less water), make sure you have a tank to serve as your control, with no changes so you can see how much algae you would expect to have normally. You will also want to carefully consider other possible variables and try to keep them as controlled as possible between your experimental tanks. For example, one of your tanks will not have any light, but how much light will the rest of your tanks get? It needs to be the same for all of them. Another of your tanks will have water removed each day. For the rest of your tanks, will you keep the amount of water consistent, topping it off with extra water when necessary, or will you allow the water level to decrease due to evaporation. You might want to research what other factors might affect algae growth/death? I'm guessing temperature and pH might be important, so you'll need to keep that controlled between all of your tests. To make your experiments really strong, you could measure the temperature and/or pH of your tanks daily and keep a log, in order to show that it didn't change between your groups.

Two other questions to think about:
1) How do you plan to measure the amount of algae present in the tanks to compare between groups?
2) Will you only do on final measurement of algae at the end of your experiment or will you plan to measure it periodically throughout the experiment so you can plot the decrease over time?

Finally, it may not be feasible depending on the number of tanks you have available to you, but scientists generally like to do more than one test of each experimental sample (i.e. replicates). In other words, if possible, it would be best to have two or three tanks for each condition (i.e. two tanks with algae eaters, two tanks with plants, etc.) This helps us to make sure that any differences we see are not due to pure chance.

This sounds like a really interesting project, and you are well on your way to a great science fair project. I hope this helps and please post again here with additional questions.

JMP

Thank you so much for your reply, it really helped me. I'll contact you if I need further help.