Can muriatic acid be safely used to remove mineral buildup in toilet siphon jet?

Saturn94

Bronze Supporter
Mar 11, 2015
1,754
SE Virginia
Pool Size
20000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
We have a toilet that flushes too slowly. A quick search online and some simple diagnostics revealed the siphon jet at the bottom of the bowl and rim jets under the rim are clogged with mineral buildup (the siphon jet at the bottom of the bowl is almost completely blocked!).

I’m in the process of soaking the siphon/jets in full strength CLR as directed in a video I found by a master plumber. After soaking a couple hours I was able to get some chunks out, but there is still quite a bit still partially blocking the siphon jet, so I’ll let it continue to soak.

If CLR proves not up to the task of removing all the mineral buildup, is it safe to use muriatic acid (31% full strength stuff or 14% low fume)? Any suggestions on how to use it? A search online gives mixed results. Some say ok to use, others say no way, it will damage the toilet and is hazardous.

Hopefully, some of our chemistry experts here can offer advice. 😀👍

Thanks.
 
Ha.

If you get some Lysol Toilet Bowl cleaner (the Power brand) and check the ingredients you’ll see that it’s basically 10% HCl. It’s also formulated as a gel so it clings and sticks to the porcelain surface. That should be effective enough to dissolve scale.

I wouldn’t use pool acid for this. It’s way too concentrated and if any of the underlying metal beneath the porcelain is exposed, you will corrode the heck out of it.

You’re probably going to have to mechanically chip out the scale to some extent. That much buildup is very hard to remove just using liquid chemicals.
 
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If it’s a two piece bowl, it may just be easier to drain the entire toilet, remove the top tank portion and then try to mechanically clean the jets and siphon while it’s dry. It would probably be easier to pull the entire toilet and put it up on a work bench to get at everything …. just remember to plug the waste line in the floor with a rag or else the swamp gas will send the other occupants of the home running for fresh air 🤢
 
Ha.

If you get some Lysol Toilet Bowl cleaner (the Power brand) and check the ingredients you’ll see that it’s basically 10% HCl. It’s also formulated as a gel so it clings and sticks to the porcelain surface. That should be effective enough to dissolve scale.

I wouldn’t use pool acid for this. It’s way too concentrated and if any of the underlying metal beneath the porcelain is exposed, you will corrode the heck out of it.

You’re probably going to have to mechanically chip out the scale to some extent. That much buildup is very hard to remove just using liquid chemicals.

Thanks, Matt. 😃

I appreciate the tip to use Lysol cleaner. I’ll probably pick some up for regular maintenance to keep scaling at bay going forward.

After several hours of soaking in CLR and quite a bit of mechanically chipping out, I think I got the siphon and rim jets cleared. It appears to be flushing better, but l see how it actually performs when used.

And it’s surprising to hear about that much scale build up … you must have very hard water.

Actually, our water isn’t really hard. We have 3 toilets in the house, about 30 years old, and the one in the master bath is the only one that scaled up so bad in the siphon jet. A bit of searching online revealed that what likely caused the siphon jet to scale so much was our habit of not flushing when having to urinate during the night as to not disturb one another sleeping. The other toilets are always flushed after each use, hence no scaling in the siphon jets. There was some scaling on the rim jets on the other two, which I went ahead and mechanically cleared. After decades of use I guess that can be expected even with water that isn’t very hard. So, lessoned learned, flush every time!

If it’s a two piece bowl, it may just be easier to drain the entire toilet, remove the top tank portion and then try to mechanically clean the jets and siphon while it’s dry. It would probably be easier to pull the entire toilet and put it up on a work bench to get at everything …. just remember to plug the waste line in the floor with a rag or else the swamp gas will send the other occupants of the home running for fresh air 🤢

I hear Home Depot is running a sale on new toilets ….

Here’s hoping what I did worked and won’t have to go that far. 😀🤞
 
I DO NOT RECOMMEND THIS

However, my father was an auto mechanic. I remember when I was a kid we had a toilet that was flushing poorly because of mineral build up. He brough home some battery acid and added it to the toilet.
It flushed much better after that.

Knowing what I know now, not as a young kid. It was quite dangerous, and likely not good at all for the cast iron drain pipes in that house.
 

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