Stupid Pool Guy

[Avengelyne]

We have a rental house with a pool. And pool suddenly has a few stains around ladder and bottom of pool.....we mentioned this to the pool guy cause he just did some yearly maintenance or some crap and his reply was our kids must have put bubble bath in the pool...and that the pool has to be drained and treated....odd thing is...this wasn't a problem until we mentioned it to him, thinking maybe one of the chemical was a little to much...long story short...pool guy calls landlord and now he wants to keep part of security deposit for this.....my kids didn't put bubble bath in the pool...but if they had...would that cause a few brown stains?