i'm debating whether or not i want tahitian moon sand for my 10 gal tank. i want the tank to be planted (low light). i really like darker substrates. any thoughts? will tahitian moon sand be ok with plants? i've heard it looks bad because you can see every spec of dirtiness on it. is this true? can tahitian moon sand be vacuumed like gravel? i heard that PFS can be vacuumed just like gravel, which is one reason why i was going to go with it. some cons with PFS--the light color, and i can only seem to find giant bags of it and i only need enough for a 10gal. i don't mind paying a little more for black or dark sand. any suggestions for similar priced (to the moon sand) dark substrate?