Three sealed bags in the window. A radish in one. Algae in one. Algae and brine shrimp in the third.

By Friday they look nothing alike, and the class works out why.

The bag with the animals in it ends up less green than the bag without them. Nobody predicts that.

The radish seed sits flat against the plastic, so the root grows down the bag wall in plain sight. Most classrooms never get to see that.

And then the tubes

A dozen small tubes turn the kit into an experiment instead of a demonstration. Radish in the light against radish in the dark. Algae in the light against algae in the dark. A row of tubes getting saltier until nothing will grow in the last one.

Every student gets a tube of their own and the teacher keeps the controls at the front of the room.

In the box

• 3 Beaker Bags, 500 mL, with a printed 1 mm grid
• 12 self-standing 50 mL tubes
• 3 petri dishes
• 2 tubes of live algae, 15 mL each
• Brine shrimp cysts
• Seawater salts and nutrients
• Radish seed and vermiculite
• Hand lens
• Secchi Stick
• Pipette
• Paper towel

You supply

Bottled spring water, not distilled. A light or a window out of direct sun. Chart paper. A flashlight for the light work, and some foil if you want to run things in the dark.

Lessons, and you can read them before you buy

What Eats Light? ships with the kit. Teacher, Student, Assessment and Administrator documents, written once for K-2 and again for 3-5, with standards mapped to NGSS, Texas TEKS and Florida NGSSS. All four are free to download right now.

Grades K-2: Teacher | Student | Assessment | Administrator

Grades 3-5: Teacher | Student | Assessment | Administrator

Editable Word versions are here. Change the wording for your own class, we do not mind.

If you are the one who has to justify the purchase, start with the Administrator Package. It lists every standard the week covers, and it says plainly which ones are a full match and which are a stretch.

More lessons run on the same box and we publish them free as they are finished. Light and dark. How salty is too salty. Where the salt goes when the water leaves. The brine shrimp life cycle, from cyst to adult. The parts of plants and algae. You will not need to buy anything again to run them. They go up on our lesson plans page as they land.

Good to know

One kit runs a classroom working in small groups. The first lesson takes seven days. The cultures keep going for months after that, and some teachers have kept one alive for years. Left to grow, the radish will flower and set seed inside a school term.

Keeping it alive that long is covered in How to Culture Algae.

Top up with fresh water only, never salt water. Water evaporates. Salt does not.

Nothing in the kit is toxic and the bags stay sealed. The radish is edible at every stage.

On the price

We know what a classroom supply budget looks like. If $78 is the thing standing between you and this kit, write to us and tell us what works. We would rather it was in your room than on our shelf.

Teachers fund these through DonorsChoose all the time. Ask us for an invoice and we will send one the same day.