Go slowly with this, Jeff. If you are starting at 29%, and going to add a cup (4 oz) to a couple gallons of water (256 oz each), you are going to have a mighty diluted solution. Plain ol' vinegar (acetic acid) from the grocery store is 5% right out of the bottle. I wish I could advise you what ratio to use, but I honestly have no experience with acid cleaning a fuel tank.
I bought some muriatic acid for a swimming pool just a weekend or two ago. I thought this was closer to the 98% purity. I'm confident it was LOTS more potent than 29%. Then again, I have no idea what product you bought. Mine goes for about $5/gallon, as a benchmark.
With acid, add the acid to water not the other way around. It won't dissolve plastic containers. (I live where the soil is VERY alkaline. If I dilute acid to a very low concentration and pour it on the lawn, the grass greens up!) Probably the safest approach is to sprinkle in some baking soda into your reclaim- it will react with the acid, and you'll end up with a type of salt water. This is safely transported and disposed.
I'm sure there are folks plenty more smart about this than I am. Allow them to weigh in and get the benefit of their opinion and experience.
Bill
