Table 1.

The density and related buoyancy of various materials and Marimo

Part	Material	Density	Diameter (Length) ∗	Weight	Buoyancy
		g cm −3	mm	mN	mN
Float (sphere)	Polypropylene (PP)	~0.9	25.4	71	7.8
Marimo (sphere)	Filamentous algae	~1.0	50 – 60	520†	-4.9
Bubbles	Gas (O2, CO2 & N2 mix)	0.001	0 – 5	0	0 – 20
Weight (sphere)	Polyoxymethylene (Delrin®)	1.42	11	9.0	-2.6
Link ∗	Nichrome wire	8.4	(75)	1.5	-1.3
Combined Overall					− 1 t o + 1 9

^∗Dimensions are given as diameters for spheres and as length for the ‘link’. ^† The Marimo ball has a weight of 88mN once desiccated