Pool Filter Sand. Coarse-textured sand for use in aquariums housing digging and/or sifting fish. Heavy sand not prone to being taken up by filter intake like the lighter, fine-textured sands.
(Particles and Fields Subsatellite) Subsatellites released from Apollo 15 and 16 into lunar orbit to collected data on particles and fields in the Moon`s vicinity. Spacecraft Release date Mass (kg) PFS, Apollo 15 Aug. 4, 1971 36 PFS, Apollo 16 Apr. 24, 1972 36
Purge Flow Sensor