Hello -

I'm a desperate condo-owner (in a 100 unit building) looking for someone to help me with an intractable problem with building hot water.

Long story short, I have black debris in my hot water (from all faucets) in my unit for more that six months, and the HOA has been unable to fix it.

The black flecks are solid but if I rub them between my fingers they tend to disintegrate.

The debris is ONLY in the hot water.

The only people who have reported this problem are a couple of the units that share the same plumbing stack with us (the building is 10 stories tall, and we're on the 4th floor).

All the pipes in my unit and the building are copper; I've replaced any and all gaskets, valve catridges, braided hoses, supply hoses etc. The building replaced the hot water heater less than a year ago. The hot water tank itself was relined about three weeks ago.

And the problem still occurs...

I've come up with a potential explanation of this and would appreciate any feedback to see if I might be on the right track - any and all thoughts are appreciated.

My potential explanation is that:

1. The black dirt is magnesium sulfide created as the magnesium anodes in the hot water heater corrode.
2. The water heater is on the roof of the building. The main hot water feed for the building enters through the roof immediately above our stack. My thought is that the magnesium sulfide "dirt" collects toward the bottom of our stack since gravity will cause the "dirt" to settle at the bottom of the stack. This would explain why only one stack in the building is reporting this problem, since for other stacks the pipes branch off horizontally, giving the black dirt an opportunity to settle out before reaching the vertical stack.

Questions:


1) Am I right that the magnesium anode is causing the problem? If so, what do we do? Are aluminum anodes really safe for drinking water, considering the (reported) health risks of aluminum?

2) If we stick with magnesium anodes, is there any way to prevent the magnesium sulfide from getting out of the hot water tank and into the water supply? I.e. is there a way to filter the hot water to get rid of the debris so we can still use a magnesium anode rod?

Thank you so much in advance for any advice or insight you might be able to share.

Best,

John

Have the owner change out to another type of rod,they make different ones...good luck..