Solution for the yellow spiders: Move spider 2 to A; 3 to B; 1 back to 1.
Solution for the blue spiders: Move spider 2 to A.
Take the RECIPE HALF (D).
Put down the RECIPE HALF (E); pour the SODA into the test tube (F).
Shut the test tube (G); take the GLOW STICK (H).
Throw the GLOW STICK down the drain (I).
Go down the drain.