Brown spots that form into bulbs that empty to form a crater

[ConcernedTX]

Help. This is my dads pool. He tests every week more than I do and this is staring. Chlorine pool with brown spots that form into bulbs that empty to form a crater. Is this bad chemicals or bad work job?

 

[Charlie_R]

Re: Brown spots that form into bulbs that empty to form a cr

Just out of curiosity, what is the pool's pH?

For that matter, do you or your dad have a good test kit?

If possible, could you post a full set of test results?

 

[Richard320]

Re: Brown spots that form into bulbs that empty to form a cr

Just out of curiosity.....is that pool painted?

 

[onBalance]

Re: Brown spots that form into bulbs that empty to form a cr

If the brown spots are raised up off the surface and are very rough or sharp, then it maybe that they are calcium nodules that form on cracks and delamination spots in the plaster.
If that is what they are, then that is not "bad chemicals" but rather bad bonding on the plaster job.