Just curious. Is that a good idea to use an impact wrench on an old anode rod? Would it knock debris from it into the tank?
The alternative would have been to not removed the old anode. The WH was about 12 years old then. I actually broke a HF 1/2 inch impact wrench, returned that with the socket set, and bought 5/8 instead. That seemed to have barely made it, although my compressor was only good for maybe 50 PSI.
I put in a full port ball valve instead of the plastic drain. I flushed the WH out extra well... I used the anode hole to spray water into the top during the repeated flush process. I alternated that with turning on the supply valve. I did not have a pressure washer, but if I did, I would have sprayed inside with that.
I got rocks. Sand. And dark water. I added laundry detergent. I added phosphoric acid in a later attempt. I kept going until things were as clean as I could do . I might have been better to replace the WH, if I placed a value on my time. A new WH would t have been more efficient. A new water heater might have been less reliable due to electronics. I don't know.
I drained into a plastic tub rather than put rocks into my plumbing. I used a utility pump to pump water outside, and I emptied the tub of solids by dumping it. I think the rocks may have been pumped up before the softener was installed. I cannot be sure of that. They could have come from the softener, but I don't think so. The distributor basket was intact when I took that softener out of commission. I suspect they came in while the softener was in bypass at some point. No rocks can come in now, since I have the backwashing filter followed by cartridges.
One of my objectives was to replace the anode with a powered anode. That does not contribute to producing H2S. Some people remove the anode and put in a brass plug. I did not want that. I had ordered that anode before I decided to get the iron+H2S filter. Anyway, now no H2S smell. No iron.