Hard Water or Rust?

[CharlestonMatt]

What's up y'all!? Hope everyone is well.

Couple of things... first is, are these stains rust or hard water? Second would be how to clean this the right way? Third would be why is this happening? From water pooling up and drying leaving this? Is this something I should just deal with and clean occasionally or try to add some grout or matching caulk or something of that nature?

Pretty sure the subways are ceramic while the pebbles and slats are marble. Mapei Ultracolor Plus FA grout were used throughout.


Whatcha think?

[CharlestonMatt]

Correction: The wife informed me the slats and pebbles are dolomite.

[makethatkerdistick]

It could be rust if you have an old tank water heater. More likely, it is just this reddish biofilm I get as well in my showers, Best to remove it regularly. Depending on whether your grout is porous (cementitious) or not, this will inevitably grow into the grout. You can pull out the sealant and replace with fresh one, but you cannot grout over the old grout without removing it to a certain minimum depth.
Choosing white cement grout and a light natural stone on the shower floor, you have naturally set yourself up for this sort of trouble, but it seems this is just a visual distraction rather than a big problem.

[Davy]

Dolomite is similar to marble and likely a little more durable but you will still have to be careful when cleaning and avoid anything acidic like citrus, vinegar, etc.

There is a common orange mold found in showers. Not sure if that's what you have or not. I have used Krud Kudder cleaner on marble and is safe. You might try that. They make several types of Krud Kudders, I use the original. Spray some on the area, let it dwell about 10 minutes (very important), scrub it well with a brush and rinse it.

You probably need more ventilation in the bathroom. A small fan helps and be sure to keep the door open when the shower isn't being used (just a few inches will help).

[cx]

I'm thinking Davy meant Krud Kutter, but I can't prove that.

[CharlestonMatt]

Thanks for the tips.

[Davy]

Yeah, that's the stuff.