So, basically I live in a region where the water has a lot of limestone content and calcium gets stuck to everything. In my house one of the toilets has this issue where water comes out only from the front holes of the flush and the rest of the holes are clogged with calcium deposits.

If I use acid I think it would only fix superficially and I think some of the holes have a lot of calcium, so the easiest option I think would be to physically drill with a nail or a hard wire, the thing is that it's quite uncomfortable to reach and to be honest a little nasty...

I tried using a small mirror (like a dentist) and a small screw held with pliers. The thing is that I think the holes are a tiny bit smaller than the screw so it's not a good fit. I am going to look for a tinier nail and try to use it.

Any recommendations?

  • Toilet Duck. Aims under the rim. i.stack.imgur.com/L8rRb.png There are a million similar household products.
    – Tetsujin
    Dec 7, 2021 at 19:41
  • Temporarily block the holes that work and soak with coca cola…
    – Solar Mike
    Dec 7, 2021 at 20:06
  • My answer to basically the same question - and some other answers there to look at as well. diy.stackexchange.com/a/51532/18078
    – Ecnerwal
    Dec 7, 2021 at 22:30
  • Once you get the toilet clean, I'd strongly recommend you look into a water softener or other filtration system to get the calcium out of the water before it builds up again. That will be the long-term solution to your problem. You are getting this build up in all of your plumbing, it's just that the holes in the toilet rim are the smallest, so they've clogged first.
    – FreeMan
    Dec 8, 2021 at 13:13
  • @FreeMan I do agree on this but it would be quite expensive and the house is rented. Dec 9, 2021 at 1:03

2 Answers 2


I have this same problem. What I have done is turn off the water to the toilet and hold the handle down until all the water is emptied. Then, inside the tank, manually prop open the flapper and pour a bunch of vinegar (or some other acidic cleaner) down the hole. This works well because it lets the cleaner attack the mineral deposits from the back, so everything gets soaked more thoroughly. You'll need to use quite a bit, and it has to be poured down pretty fast. Then let it sit for a few hours or over night.

Just be careful to not get any chemicals on the flapper or on the gasket that it seals against. If either of those sealing surfaces is damaged by the acid, the toilet might start emptying continuously and having "ghost flushes". If that happens, you might need to replace those parts.

  • So, just to get this correctly, I empty the flush tank and leave the flap open and put a bunch of either CLR, hidrochloric acid for house use, or vinegar inside the flush's main hole. And that would start eating the clogging from the inside although some of it would be going out of the holes right? Dec 9, 2021 at 1:01
  • Yep, that's right. It's also important to pour the cleaner quickly so it can reach the whole way around the rim. If it gets added too slow, it will just run out the unblocked holes before reaching everywhere you need it. You could try blocking the holes with masking tape, but that's probably not necessary. Last time I did this I poured about a pint of CLR down and left it overnight.
    – Z4-tier
    Dec 9, 2021 at 6:36
  • Ok, another thing tho is that I think my toilet type is similar to this one i.pinimg.com/originals/47/a7/59/… so, the thing is that when I pour something it ends up below the water in the tank because it's used to push the contents down. So I am not sure how long the cleaner would stay there. I do remember CLR is a little more thick in consistency, but not sure about the rest. I tried putting the duck liquid and it painted the lower part of the water blue, so it went right through. Any recommendations on that? Dec 9, 2021 at 21:45
  • This image familyhandyman.com/wp-content/uploads/2019/03/… is much clearer... so basically everything I pour comes out of the siphon jet. Would CLR stay for longer? Dec 9, 2021 at 21:48
  • There is really no way to avoid that. The best you can really do is to pour enough down to saturate the blockages at all of the individual jets. CLR is not particularly thick, maybe a little more than vinegar, but not much. If you're concerned about loss, you could also try pouring vinegar down there several times in a row, perhaps once every hour for several hours. Maybe even pour some regular toilet cleaner, since it's much thicker and a pretty strong acid (HCL).
    – Z4-tier
    Dec 9, 2021 at 22:26

Any good decalcifying agent will work - CLR, Kaboom,to name two, or even vinegar. The hard part is getting it up into those holes under the rim. I suggest you get yourself a set of small round wire brushes, dip them in a decalcifying cleaner and ream out the holes.
There's also a large jet at the bottom of the bowl that jets water toward the back of the bowl. It's larger than the others but critical to clearing the bowl on each flush. Make sure it's clear as well.

enter image description here

  • This looks like a working option but wouldn't it be harder than the option Z4-tier proposes? Dec 9, 2021 at 1:02
  • Yes - that option is fine but difficult to protect rubber components. However, if you go that route you'll still want to ream out the holes with a small brush to get rid of any excess calcium deposits.
    – HoneyDo
    Dec 9, 2021 at 4:03

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