After getting the anode replaced last week, I turned the tub faucet to full hot, and they were right - barely a trickle.

It's time to play with cleaning vinegar again.

So, I closed the master feed valve, opened the cold-water inlet and poured some 30% acetic acid into the hot water tank.

Two gallons of acid later, I replaced the pipe fittings, opened the cutoff valve and was relieved to see no water spurting across the room.

Next step was running the water in the tub until the acid-infused water reached the clog.

It should be easy to just run until I smelled the vinegar, but by now my nose was dead, and the whole house smells like an italian salad.

But, I remembered my experiment with juicing buckthorn berries.

My friend Randy Asplund demonstrated how you can use buckthorn for medieval dyes at the Ann Arbor Book Fest. Basicly, buckthorn berry juice turns deep purple when it's in an acidic solution, and green in basic solution.

I gathered a bunch of berries from the nearest tree, smushed them with a fork, moved a sample into a small juice glass, added water and a little baking soda, and presto - I've got a bright green slush of pH indicator.

I poured a little of that into another glass, added a little water from the tub, and it stayed green.

So I ran the water some more, and eventually when I added tub water to the green goop, it became cranberry red.

As a rule, I prefer Deep Purple to The Cranberries, but this was good enough for me.

So, I let it sit. A few hours later the hot water was gushing again.