jflow:
Please post specific gravity as three decimal places.
1.9 could be 1.009 or 1.090, probably the latter, but I'm pretty sure that it isn't 1.900 (which is what 1.9 means).
0.9 isn't 0.900 (which is what 0.9 means). It could be 0.990 or 0.999.
1.090 to .990 in 5 days is doable with the right conditions. .990 means fermentation is complete. .999 probably means fermentation continuing slowly.
Steve