Take 10 grams of sawdust [see the woodshop teacher] and place it in 100ml of seawater. [Different woods will give different results, so be sure to record what kind of wood was used.] Bring the water/sawdust to a gentle boil and boil for at least 5 minutes. [You may have to add distilled water to make up for lost volume] [this can also be done in a microwave]. Filter the water/sawdust through a coffer filter. This is your stock solution.

All dilutions are made with normal seawater

1. Add one drop of concentrated eggs to each.
2. Swirl and let sit for one minute.
3. Add one drop of diluted sperm suspension and swirl briefly.
4. Wait 5 minutes.
5. Score eggs for fertilization. If time permits can also score for later development [Next period see if divided. Next day see if there are swimming blastula]