"Mold" in a Tile Shower - Can I use Calcium Hypochlorite?

[UnderWaterVanya]

I have some persistent "mold" (perhaps black algae?) in my shower that needs to go away. Bleach sprays and mold sprays don't seem to really get rid of it. A lot of the mold is in the caulk - so my plan is to treat around the caulk, strip the caulk and then treat again with no caulk - and finally add new caulk.

I was thinking and wondered if I could safely use calcium hypochlorite and make a high concentration chlorine paste to spot treat this stuff.

Previous treatments have been over a month or two ago and used sodium hypocholorite as far as I know.

Thoughts?

 

[duraleigh]

Re: "Mold" in a Tile Shower - Can I use Calcium Hypochlorite

Cal Hypo would be fine but, more importantly, we know that chlorine, in any of it's forms, kills algae. The issue with shower mold is the chlorine can't get to it.....not that there is some super resistant strain growing in showers.

So, stripping the caulk to expose the algae to chlorine is essential. IMO, chlorine in liquid form penetrates the best......you simply have to provide a path so you can make direct contact and then do some physical brushing to expose the algae surfaces.

In short, I don't see any benefit to Cal Hypo in that application.

 

[openpool]

Re: "Mold" in a Tile Shower - Can I use Calcium Hypochlorite

I'm often faced with this problem too. But just like the shock process for a pool, don't forget you need to keep hitting it with Bleach spray hard, not just once or twice.

 

[Richard320]

Re: "Mold" in a Tile Shower - Can I use Calcium Hypochlorite

If the black is around the seam where the tile meets the tub, I have a solution for you: paper towels. I found that rolling a paper towel into a tube then wetting it with household bleach and packing it along the seam will leave the caulk gleaning white in a couple hours. I got in the habit of re-wetting it with bleach at least once while it sat there. When you peel them up, it's scarcely better than paper mache, but the caulk sure is clean.

 

[UnderWaterVanya]

Re: "Mold" in a Tile Shower - Can I use Calcium Hypochlorite

If the black is around the seam where the tile meets the tub, I have a solution for you: paper towels. I found that rolling a paper towel into a tube then wetting it with household bleach and packing it along the seam will leave the caulk gleaning white in a couple hours. I got in the habit of re-wetting it with bleach at least once while it sat there. When you peel them up, it's scarcely better than paper mache, but the caulk sure is clean.

That's a great idea - but in this case the black goes through the caulk also. I'm going to rip it out - and maybe use your idea to make sure I keep bleach in contact with the area. Thanks. I just liked the simplicity of a paste but since I only have sodium hypochlorite, dichlor and trichlor I don't see the benefit of running out and buying some calcium hypochlorite too. The dichlor and trichlor came from before I knew any better... luckily I bought small quantities.