On filters and flush water color changes...

Here is an interesting email posted by a resident under the subject line - [Flush Water color change Co-incidental or the fact (Myth Busted)]

I have problem in the common toilet flush, the water doesn't fill up soon, it takes mins (>10) to fill it up.
I have the complaint and the plumber came and checked, resolved the issue.
When i inquired about the issue, he replied, the filters are blocked dues to bad water quality.
he cleaned the filters are all good for couple of weeks.

Then friday it was the same issue, and the same plumber came on saturday.
This time he finished the job in few mins and no cleaning done.
But the issue resolved, when i inquired he said i have removed the filters and you will not have any problem.

Yes, the problem is resolved but when i asked if you remove the filter won't the dirt come into the pot.
for which he replied, this is the same in most of the flats, you will not find this issue anymore.
Most of the flats are with out filters.

In fact, i learnt that there will be two filters and he spared one for me, but most of the flats do not have both the filters.

But, since yesterday(Sunday) the water color is black, and worst of kind.
looks like directly coming from gutter.

Now, the problem of bad water quality in flush tanks is because of the removal of filters or
it is due to the bad treatment of the water.

Maintenance Team, kindly confirm.

@all, do you remember this kind of issue and then you started getting bad quality water ?

Thanks,
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