[jocko]

Then again vinegar won't singe your nose hair. If you choose muratic acid, make sure to take all the precautions. It will eat through blacktop and is harmful if inhaled too much. I'd just go with the vinegar personally - then you don't have to worry about disposal either. Muratic acid is a different story, can be a major pain to get rid of it (properly). I've used it, probably won't again except for derusting small hardware - but there are many non-toxic products on the market now to choose from. I'm no tree hugger by any stretch, but I would not dump it on the ground or down the drain (not that anyone is suggesting that - but rinsing the tank will produce a large mix of water and muratic acid with nowhere to go).