I think you should have rinsed off all that sand and dirt first. I figured that out my last go round. I think you only need about half of that water. You just have to cover the item you're cleaning and maybe a couple more inches. More water, means more diluted I'd think. But, it might be a good thing too. So it being an experimental process, leave it run with all that water and lets see how it does. If all your are using is that piece of rebar for an electrode, you're gonna need to clean it often, and slows the process. Its also going to clean closer to the electrode better than the other end. Great candidate for the process though. I am sure that will come clean, just gonna take awhile the way you have it set up. So you don't kill your charger, I think I'd bring it down to 10amp. I just wouldn't use my highest setting for this. I used 40amp last time, but it was a 40/160 charger/starter, so I figured the windings in the charger could handle the 40amp without a problem. And my other charger 2/10/50 had an internal breaker that kept blowing at 50amp, which told me, it was overheating. If yours don't have a internal breaker, you just might be overheating it. I'd bring it down to 10amp if were me. I had good results on that block at 10amp.