What is the best way to keep grout in the bathroom from turning black?

Whatever you opt to do, avoid using vinegar on it as vinegar will damage, etch, and over time dissolve your grout.

Use a good quality grout sealer on it. Do an internet search on 'sealing grout' and you'll find lots of videos on the subject.

Vinegar kills the mold spores, bleach does not.

https://www.servicemaster-restoration-cleaning.com/2017/03/mold-myths/

A paste of vinegar and baking soda will do the trick. However, Becky is correct, as over the years, repeated cleaning can disintegrate the grout. To combat that, seal it, or pay for a professional to come in and do for you. Then reseal once a year thereafter.

My mom's house was built I the mid 1920's. The main hall bath still has some original tiling from when the house was originally constructed. My dad sealed it a couple times a year (For a bit it was the only bathroom in the house till my dad built a second one and powder room), and we always used vinegar and baking soda to clean the grout. I remember when it was one of my chores and my brother and I traded off and is still there to this day, even after all the earthquakes it has been through.

https://m.wikihow.com/Clean-Bathroom-Grout

https://www.bobvila.com/articles/cleaning-grout/

https://www.thespruce.com/grout-cleaning-and-maintenance-guide-4048446

First, you need to get it clean, then seal it. Also make sure that you have an exhaust fan that will handle the size of your bathroom. Be sure to run it at least 15 minutes after the bath or shower is done.

Hi Alvina - This is the shower cleaner that we use to help keep grout and tiles clean and minimize the mildew - it works on kitchen grout too. Hope this helps! Hugs, Holly

https://pinkfortitude.com/shower-cleaner-diy/

PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean

Spray with hydrogen peroxide full strength let sit for a few...then with an old toothbrush dip in Baking Soda + scrub...

Mold DOES disappear...

Black grout I have found means mold spores are flying around the hose most likely brought in by wind and animals..pure javex works well in my place.place a cloth over your nose and mouth, and use a spray bottle...after 24 hours do again...and then rinse with hot water....reducing the humidlty quickly after a shower...by wiping down the walls and putting the towels outside to dry..some molds thrive on the grout as a food source..others will turn a toilet bowl black over night..I now wash all fruits and vegtable in a vinegar bath before placing in the fridge..not only has the mold population gone down in my home, so have the gnats, and I don't cough as much...hope this helps...a tooth brush to get into mortar cracks also helpful..dipped in javex ...if javex objectionable - painter's vinegar can also work...but don't use that on food..

First, clean, clean and then give it a good paint on grout sealer. It works great !!

Your home store has all you will need.

Howi

Spray it down With Clorox Clean Up and leave the room. Be careful not to get it on chrome. Rinse the drain chrome before you leave the room. The bleach will pit the chrome.

Repeat this as many times as needed. I've had a couple of cases where this took a few times.

Remember to never mix cleaners. Rise everything well before you use another cleaner.

Squeegee or dry the walls when you take a shower to reduce mold. Run the fan for a while to dry the room out. Whenever you see a spot of mold - zap it with the Clean Up.