Thanks folks for the replies. Got an added problem to the stink. Bottom line is that I have to drill a two to 3 inch hole into top of tank..right above the drain/fill tube. Something is obstructing the drain/fill tube. Took all the valve assembly off, used air hose to blow back into tank to dislodge where the water drains at bottom of tank. It drains good for a bit, until it clogs up again. Access to top of tank, wet\dry shop vac with attachements, suck up whatever is clogging the line, and should be able to suck out sediments and various other ickies! Plug hole with a rubber thingamagigger..sanitize garden hose, tank, fill..drain and repeat. I'll let ya know how it went! Thanks again!