Macro Algae Jr High Science Project

[jabberwock]

I have a big batch of Red Grape Caulerpa. My kid wants to do a Jr High science project with it. So here are a couple ideas and questions. She wants to base her study on either light, or nutrients. So, start with the hypothesis, weigh out 4 samples of algae. Set them up in four mason jars with a bubbler, using tank water from a water change. Apply different lights, or add different nutrients to each. After a period of time, remove the samples and weigh them again to quantify growth. No test kits can be used. No animals can be used.

My questions are:

1. How much time would we need to show significant growth?
2. What lighting options are there to isolate red, blue, full spectrum, and zero light?
3. Or, what nutrients and how do I add them without using fish or bacterial biome?

Here is a full tank shot to thank you for looking! (ps - sample algae is growing in a smaller separate tank)

 

[Dan_P]

I have a big batch of Red Grape Caulerpa. My kid wants to do a Jr High science project with it. So here are a couple ideas and questions. She wants to base her study on either light, or nutrients. So, start with the hypothesis, weigh out 4 samples of algae. Set them up in four mason jars with a bubbler, using tank water from a water change. Apply different lights, or add different nutrients to each. After a period of time, remove the samples and weigh them again to quantify growth. No test kits can be used. No animals can be used.

My questions are:

1. How much time would we need to show significant growth?
2. What lighting options are there to isolate red, blue, full spectrum, and zero light?
3. Or, what nutrients and how do I add them without using fish or bacterial biome?

Here is a full tank shot to thank you for looking! (ps - sample algae is growing in a smaller separate tank)

Some quick thoughts

You can feed the algae ammonium chloride and phosphate daily. They can consume it very rapidly. In fact you can measure the consumption rate, like ppm/hr, for extra credit. Total ammonia consumption will correlate with algae weight gain.

The green algae will likely grow quickly. Depending on light intensity and scale sensitivity, you can measure change daily. If nothing is happening in a week something is wrong.

Use a strong bubbler to clear the oxygen and keep up a good supply of CO2.

Water changes would be a way to avoid trace element depletion and growth slowing.