Why PH Is Important When Cleaning Marble and Stone
When I first started cleaning houses, I noticed that some marble countertops had an etching pattern on them. It almost looked like scratches or a discoloration. Sometimes I would notice a circular shape - similar in size to a cup. In other places, there would be dots or “splashes” of discoloration.
I noticed this occurring shortly after some people would remodel their homes and install a marble countertop in their kitchen or bathroom vanity. Sometimes proper care instructions are not relayed to the homeowner in the remodeling process.
After enough conversations with contractors and due diligent research on this topic, I came to learn that marble contains what’s called calcium carbonate. When any acid comes in contact with the marble, the calcite in it dissolves. You’ll actually notice this on buildings and statues that are exposed to the elements - the material has broken down and the original formation of carved details are lost.
Essentially, when the reaction with marble occurs, metal salt, carbon dioxide, and water are formed. You might not notice this reaction however, because it’s happening on a small surface level and it’s likely you’re wiping up spills and messes on countertops on a regular basis. Each time you clean, you’re essentially wiping the reacted elements away.
While marble countertops are absolutely beautiful, they are high maintenance. Be prepared for this when moving into a new home that has marble countertops or making marble your choice of countertop material for a remodel.
Consider this article your marble cleaning manifesto. You’ll find cleaning and maintenance tips below on how to clean and care for your marble countertop.
Why is PH important when cleaning marble?
Anything that’s too acidic or too alkaline will cause a reaction when it comes in contact with marble.
The PH scale goes from 0 - 14
❌ 0-6 = acidic
✅ 7 = neutral
❌ 8-14 = alkaline
The window of PH is small for what is acceptable to come in contact with marble in order for it to maintain its pristine condition. You’ll want to use a product that is close to neutral as possible. A PH of 7-10 is acceptable (you can go a little alkaline). You’ll want to steer clear from any cleaning products that are outside of this PH window from coming in contact with your marble countertops. You’ll also need to be careful to not leave any low/high PH liquids sitting on the surface with regular activities in the kitchen. Some examples of different cleaning products that go low to high on the PH scale/spectrum:
❌ 2: Lemon juice, vinegar
✅ 7: Dish soap
✅ 8: Baking soda
✅ 9: Hand soap
❌ 11: Ammonia
❌ 13: Bleach
Image by Aleksandr Slobodianyk
Can citrus ruin marble?
YES. Citrus is acidic, making it low in PH, outside of the recommend ‘neutral PH’ window that’s acceptable for marble countertops. A short quick list of some acidic liquids that can ‘ruin’ marble or cause etching/stains:
Coffee
Soda
Lemon juice
Lime juice
Grapefruit juice
Orange juice
Tomato juice
Apple juice
Beer
Vinegar
Interestingly, some essential oils that are citrus based are safe enough when mixed in cleaning products.
Image by Karolina Grabowska
Can bleach ruin marble?
YES. Bleach is alkaline, making it high in PH, outside of the recommend ‘neutral PH’ window that’s acceptable for marble countertops.
What do I use to clean marble?
Our default countertop deep cleaning method at The Tidy People is making a soapy towel with dish soap, a terry cloth towel, and water to scrub the kitchen. That said, while dish soap is a neutral PH product, the water that you’re using to mix with the dish soap can vary greatly. This will depend on where you live — you might have “hard water” and get mineral buildup. If this is the case, use distilled water, which is neutral PH water.
For everyday cleaning (in between the deep cleans), The Tidy People All Purpose Spray is a great every day cleaner. It does have lemon and litsea essential oil in it, but is a neutral PH product when mixed with distilled water. You can also search for "marble safe” or “neutral PH” cleaners if you’re looking for something that’s pre-mixed. Beware, if it comes in a plastic bottle, the PH can change in time with storage and breakdown of the bottle due to changes in temperature.
When in doubt, you can use a PH tester or test strip to test your cleaners to ensure that the PH window is between 7-10 for the product that you’re using.
Can I remove or repair stains on my marble countertop?
Essentially, any interaction that’s happened on your marble countertop that’s caused a “stain” or “etching” is this:
There’s a part of the stone that’s disintegrated. The even, flat surface texture that it once was is now uneven. To the eye, this looks like a stain. In theory, it can be repaired but I would consult a professional who specializes in marble countertop repair. This will require sanding the uneven surface and then sealing the countertop again.
How do I prevent etching or stains from occurring?
Ensure the countertop is sealed. Seal the marble countertop upon installation. Then, set a schedule for the countertops to be sealed once every couple of years — the seal will eventually wear off. This will add a protective layer between the marble and any food, beverages, or cleaning products that you place on it with every day usage.
Clean up spills right away and don’t leave food (especially liquids) on the countertop. There’s naturally going to be things that you end up spilling on the countertops (such as coffee — highly acidic). Make a habit and routine of putting drinking cups/mugs on a coaster or another surface (maybe a tray) on top of the countertop. Cleanup with your PH neutral cleaner after cooking with a quick spray and wipe of the countertop.
Add a protective layer to “hot spot” areas on the countertops. When doing prep work, ensure you have large cutting boards that are easily accessible to protect any food or liquids from sitting on the surface that are too acidic or too alkaline. Also, these silicone mats provide an additional layer of protection and come in a variety of sizes and colors, giving you different options to protect the countertop.
