Safest way to kill mold in tank and cover?

[dave53]

Hi all,

With the summer influx of springtails coming into the house searching for damp places, I've just done some inspecting and discovered a situation that I'm hoping someone here can help with.

To answer a few things up front - there is no mold around the toilet area or in the bowl or surrounding or walls, no rotting wood, and we keep the bowls very clean.

The problem I'm running into is mold inside the "dry" areas of the toilet tank and the tank cover.

We're on our own shallow water point and have our own single-family home septic tank, and I've been advised not to use any bleach products or else that could harm the septic system.

So, I'm attaching a few photos to demonstrate the mold spots in the top of the tank and top cover. As you can see, it appears to be a "dry" black mold forming a lot of spots, and of course a ton of springtails are congregating in there now, since they seek moisture / mold / fungus to survive. There were actually a lot more springtails when I removed the lid, but many jumped and scattered before I could snap pics.

Hopefully these photos are big enough, but if not I can take bigger ones.

The question - is there anything I can use to treat / kill the mold shown in the pics, that would be safe for the components in the toilet tank as well as the septic?

Thanks a ton for any advice!

 

[Twowaxhack]

That’s in practically every toilet tank I work on and I work on a lot.

You can bleach it but it’s going to come back.

 

[dave53]

Thanks very much for the reply.

This is likely a dumb question - but would it be safe for me to spray Windex on it?

The reason I ask is because I know that the Windex will also do a knock-down kill of the springtails, and I was hoping to avoid bleach if possible.

I guess the porous nature of the inside of the tank and lid is something I should keep in mind / be concerned about what I apply to it?

 

[Twowaxhack]

Windex won’t kill mold. Spray whatever you want on it.

 

[Twowaxhack]

Sounds like you need some pest control applied to keep bugs out of your home.

 

[dave53]

No Windex, won't help with mold, got it. Thanks.

As far as the springtails - they're practically unavoidable if you have a basement and live in a heavily wooded area. They live on decaying plant matter, leaf litter, mold, etc... and during the hottest summer days they come up from the soil around cement foundations looking for the damp moist cooler environment of basements. I do have control in place for that around the foundation and up under the siding - Delta Dust - but when there are large colonies of them it's not immediately or 100% effective. (And of course I keep a powerful dehumidifier running in the basement). Thankfully they're harmless to humans and pets, and do not carry disease. They just have the ability to freak you out if all of the sudden you spot a bunch of them near your sinks / tubs / toilet areas.

Sorry, didn't mean to sidetrack with that.

Sounds like maybe shutting off the water line and emptying the tank / scrubbing lightly with bleach and an old toothbrush might be my best bet.

Thanks again for your replies, I appreciate it.

 

[wpns]

I've been advised not to use any bleach products or else that could harm the septic system.

A judicious use of bleach to kill mold is not going to harm your septic system. Bleaching your laundry is not going to harm your septic system. Dumping 100 gallons of bleach into your septic system would harm your septic system, do not do that.

 

[Mitchell-DIY-Guy]

There are a variety of mold and mildew cleaners out there. Some are chlorine based others peroxide based. In cleaning your toilet innards you don’t use enough to worry much about your septic system.
RMR-86 is one chlorine based brand.
Fiber lock IAQ is a peroxide based brand.
You can also use over-the-counter peroxide, or over-the-counter bleach that you add to spray bottles and use carefully. There are plenty of how to videos and information from the usual sources on this just do a search.
Just clean it regularly. It’s not going to help you with your bugs but it will keep your toilet innards looking pretty.

 

[Bird Doo Head]

We've had the same problem that you're facing, Dave.
Keep in in mind that chlorine will send the mold into "defense mode". Upon contact, the mold will spend out spores into the air. It's best to wash the mold away first, Try to use chlorine outdoors so the launched spores won't land in the home.


Keeping the mold away was permanently solved with a two-step process:

Step A) <Optional>
You can skip this step and go to Step B once the existing mold is washed off, but not necessarily killed.
For the un-glazed areas, such as the inside of the tank lid, the goal is to seal the porosity for easier cleaning later. First, wash them well to remove the existing mold. Now kill the invisible spores with chlorine or similar or they will multiply under the coating & push it off.
Next, spray or brush them with several coats of a sealant. Poluyurethane, auto clear coat, lacquer or varnish all work. The coating also softens the roughness, making it harder for the bad guys to latch on.

Step B) <Long Term Solution>
You don't have to kill the mold for this step, but washing it off first will let the product penetrate well.
Spray the problem parts with a quaternary ammonium product. It's often abbreviated "quat" & many brands of disinfectants contain it. The goal is 200 parts-per-million or more. (Stay below 1,000 ppm or it may corrode metal if it drips.) A good source for legitimate product is a hospital or restaurant supply house, such as GFS. (It also comes without the perfume. Look for the products used in low temperature dish machines.)

The quat will kill existing spores that the washing missed. And because it has a residual effect, new spores can not grow. (The residual effect is valid for bacteria, but not virus.)

It also kills almost all viruses. Only non-enveloped viruses, such as clostridium difficile & norovirus won't be killed by quat. (It kills covid-19 at 200 ppm with a ten minute delay.)

You can skip Step A and spray the quaternary ammonium directly on the un-glazed surfaces, as well as the glazed ones. It will stay effective forever (or until washed off). In our home, one treatment about 20 years ago on grout (without coating it) solved the problem forever.

When mold and listeria got out of control, the Step B Quat treatment was used on the bare wood, concrete & block surfaces by the Health & Sanitation Department people in an NFL stadium where I worked. That stadium was a dark, damp & cool place which was ideal for mold growth. They also used it on the exposed fiberglass batting and asbestos. It was a once-and-done forever treatment.

Hope this helps!
Paul

 

[dave53]

Many thanks for your thoughtful responses and advice!

For the moment / immediate step I ended up using normal household rated peroxide (3%) in a spray bottle to assist with scrubbing off the mold with a toothbrush, including the tank lids and tank parts, and then after much sanitization cleaned everything with water and then a second round. This did a pretty darn good job for initial cleanup, and dissuaded the springtails. As an extra step I used a bulb duster with Delta around the baseboard crevices and behind the tank. Everything is looking much cleaner, and the springtails have all but disappeared.

Moving forward, next step is to do a more thorough cleaning with products you guys recommended, including quat (which I'd never heard of and now know about because of this forum), and then sealant coating for the unglazed sections.

Thanks very much for the advice!!!

 

[Bird Doo Head]

I'm glad you had excellent cleaning results, Dave.

Peroxiude was a great choice on your part. Residential dilution hydrogen peroxide (3%) is not only a super cleaner (try it on white grout) but also a very effective pathogen cleaner if it can stay wet on the surface for at least 10 minutes. A National Center for Biotechnology Information study showed only 10.8% of clostridium difficile remained. That's a great result considering its one of the most difficult pathogens to render ineffective. (It's doubtful your home has any of this unless a sewage backup occurred. If anyone in your home was infected, you'd surely know it by the symptoms.)

With the quat product, make sure it's at least 200 part-per-million. Leave it wet for 10 minutes or more. On un-glazed surfaces, re-wetting will be required to keep it wet. If you want non scented, restaurant supply stores are a good choice. They'll have the un-stinky version used in low temperature dish washing machines and on cutting boards.

Happy Cleaning!
Paul
PS: When searching for a quaternary ammonium product, you will get search results for the heavily advertized Super Oxygenated water mold & germ killing solutions. They're ineffective when pre-mixed because super oxygenated water is only useful for about an hour after being made. When fresh, it's very effective.

 

[dave53]

Thanks a ton for the extra advice and education on this! I've got everything cleaned up well with the peroxide, and now hoping within the next couple weeks to do one more round to make sure I've really killed off anything that's not visible and then follow your advice for coating the un-glazed porous insides of the tank lids with a poly or clear coat sealant. I didn't know it was OK to do that, and boy will that sure make future cleaning easier. I'm very grateful for all the info and thank you for taking the time to educate me about this!

 

[Bird Doo Head]

Thanks for the kind words, Dave53.
I'm glad your project is going well!
Paul