Apt manager or apt. maintenance should be able to replace the toilet tank or the whole toilet. This may be your only option. Your water quality could be an issue, also. You could try bleach by it itself, but if the mold is coming right back, it's probably in-bedded into the tank. If you're handy with the tools, swapping the toilet out may cost around $100, depending on where you get it. I had someone tell me they swapped one out by apt. maintenance, in an apartment, because they wanted an elongated toilet/seat instead of the small circular seat. That could be an option. Good luck with your project!- Mike

@@mikesdoityourself Tank you. Haha

Well, anywhere there is sitting water in a damp area, there is a potential for mold to grow, either from the air surrounding it or from the water quality itself. Tankless can be beneficial, depending on the frequency of use. Cleaning the area, once in a while, is probably unavoidable. - Mike

The vinegar will kill the mold, thus preventing any spread of mold spores. Good luck with your project!- Mike

I had dropped a cleaning tablet in there and it sat for over and hour. It was easy to toothbrush away I was afraid to combine vinegar with the already blue cleaning solution

@horatio_ I would never recommend mixing any cleaning products, so spraying a hydrogen peroxide solution or bleach solution are good products to get rid of mold and, of course, rinsing with clean water afterwards.- Mike

@@mikesdoityourself agreed. I had dropped one of those blue tablets in same day (reason why I opened the tank) and saw the mold. It has an active cleaning agent which I’m hoping did a good job impacting the mold. When I cleaned with the toothbrush I dipped in the blue tank water.

The water in the tank is clean. Not gross or dirty

I would replace the whole toilet myself or have someone replace it for me if you're not able to. All you'll need is to be able to shut the water off at the wall next to the toilet, then you're able to replace it. The tools needed are sockets, socket wrench, or an adjustable wrench, and a flat head screwdriver. You might need a new hose or fill tube leading from the water supply going to the toilet. There are many videos showing how to replace a toilet. Good luck with your project!- Mike

Definitely! That's why I made sure to wet down the toilet tank walls with the vinegar solution before starting. That way, the scrubbed mold would fall down into the tank easier. Good advice on the PPE to wear and use. Thanks!- Mike

Vinegar would help sanitize and eliminate some of the mess, also- Mike

I would suggest adding a cup of vinegar to your tank about once a week. Make sure you regularly flush your toilet. I would scrub your toilet tank and bowl using bleach or vinegar once a week. All this should keep the mold from reappearing. Good luck with your project!- Mike

@@mikesdoityourself Thank you!! It’s funny because it doesn’t happen to our other 2 toilets.

@Tess-he3qg If regular cleaning doesn't help, a last resort could be replacing the toilet with a new one, especially since your other two toilets are not experiencing any issues.- Mike

@@Tess-he3qgI’ve got the same problem. It only happens in one of our toilets. Very strange. I still want to find out why it’s happening because I’ve never had this issue before.

Mold spores are in the air, which when introduced into a dark, damp environment is the perfect place for mold growth. - Mike

Thanks

I'm puzzled due to the fact that my bathroom door is always open and I just have a curtain with ample space on the bottom for air to circulate & my air filter runs 24/7.... how can the mold continue to persist? It is an old building but i didn't have that problem in the other apartment I used to live in on the 2nd floor? @@mikesdoityourself

Also, when you flush the toilet a negative pressure is created in the tank so it sucks air inside. And all air inside contain mold spores in some concentration. You can't avoid that. @@mikesdoityourself