Sulfuric acid

[John McShane]

I have 55 gal durms that had Sulfuric acid in them. thay have been rinsed out are thay safe to used for plants and or fish

[Bob Terrell]

I bet they would.  After they are washed the ppm of the acid would be very low, if any.  Might affect your ph but don't think their would be enough of any residue to affect fish or plants.  Bit that is just my guess. Try them and see.

[Jeffrey Ihara]

sulfuric acid is the stuff of at least one major "pH down" product. Unless you're fighting with low pH already, I wouldn't worry.

[Vlad Jovanovic]

I agree, not much to worry about there. You can wash them out with some baking soda to neutralize the acid if you want to...but I doubt that would even be necessary unless maybe you have very soft, aggressive, low pH source water (most people don't seem to), or if you will be starting with all rain water, or RO water...

[Alex Veidel]

And it might make your water smell like rotten eggs for a few minutes... ;)