Wow! Just wow! I have like 4 nassarius, 4 trochas, 4 astreas and 2 tiger conchs. But my tank is much smaller than yours at 32g.100+ Zig Zag Periwinkles, 6 Limpets, 100+ Dwarf Ceriths, 6 Trochus Snails very small, 10 Nerite Snails, 8 Marginella Snails, 3 assorted smaller Conch's, 3 fuzzy Chitons, 12 Nassarius Vibex snails, and a Brittle Star. Seems like a lot but most are small and some do not survive. I must have a couple hundred snail eggs on the back glass, some have hatched. The zigzags are .15 cents each, Dwarf Ceriths are .17 cents each. I get them at ReefCleaners.com, they are great.
Almost forgot, NO crabs!
I’ve been wondering what else I could put in my tank that would clean the sand. The only snail I believe that actually cleans the sand in my tank is the tiger conchs.