I live in the country and have a well. My water is hard and has iron,
but tastes good and does not clog pipes. The worst problem is that
orange ring in the toilet that I have to clean every so often. I can
live with that, compared to what is happening in a close by town.

The town has a large deep well that fills two water towers. From there
it's piped to the homes and businesses. Apparently that water is coming
from a source that contains lots of calcium rock. What is happening is
that people in town have to replace their water heaters every few years
because the heaters can and do completely fill with calcium deposits.

A friend in town called me last week to ask why his hot water is only
warm and not hot. I went there and tested the elements in this 3 year
old electric water heater. The lower element was dead. We bought
another element, and I proceeded to shut off the cold water, and
electricity to the tank, then attempt to drain the tank. The water came
out of the drain valve drip by drip. I tried to remove the plastic
valve from the tank, but it would not budge, and I hesitated to try
harder in fear of breaking it off. I suggested we get pails and just
remove the element and catch the water in the pails. This element was
very stubborn to remove, but it finally came out. What I found inside
the tank was shocking. The entire lower element was buried in calcium
sludge, and the electrode part of it. had broken off and remained inside
this sludge in the tank.

I grabbed a long thick screwdriver and began to dig out this sludge,
which eventually allowed to water to exit the tank faster. The water
looked more like milk in color. I asked him several times about the age
of the tank, and he insisted it was 3 years old. He finally went and
got the paperwork for the tank and showed me the receipt which showed it
was actually 3-1/2 years old. I was shocked. I've worked on tanks that
were 20 years old and never seem so much crud in them (in other cities
and towns).

The decision was to dig out as much of this sludge as possible, and
install the new element until he can afford a new water heater. This
worked for now, but is not the ideal fix. Just for the heck of it, I
phoned a local plumber, and asked him is this is a common problem in
this town. He said that closeto half of his calls are due to water
heaters that are filled with sludge, and need to be replaced. He said
most water heaters last 5 years at most.

My reason for posting this message is because I'm wondering if there is
anything that can be done to filter out this calcium before it gets into
the water heaters? I know little about water softeners, but from what I
do know, they are more intended for hard water, which would be more what
my water is, with the iron in it. Whether they will remove calcium is
something I dont know, particularly when the calcium levels are so high.

Is there anything else that can help this problem? I'm curious !!!

Lastly, I was thinking that when my friend gets a new water heater,
would it be possible to dump the old tank upside down to remove as much
of this sludge as possible from the pipe inlets, then to pour a gallon
of vinegar in the tank. Will the vinegar disolve and thus remove the
calcium? Or maybe a weak acid? It seems wasteful to trash a 3 year old
water heater if this sludge can be removed. Once he gets a new heater,
I'd like to take that old one and experiment to see what can clean it
out. I'm sure that tank could be used for many more years if that
calcium could be removed, and new elements installed.

I also think that the reason the lower element burned out was because of
that calcium coating it. The heat is not being dissipated fast enough
into the water and that sludge is acting like an insulation, which
caused the element to overheat and burn out. This is my opinion anyhow.

Has anyone successfully cleaned out a tank like this?

By the way, some of the water that did not go into the pail spilled on
the floor and it left a white coating on the floor after it dried, of
this calcium. It looks like chalk in many ways.