Pool cleaning and repair job

So we are in Corolla everyday this time of year for repairs and pool and spa cleanings.  It never gets old the things we see from other pool companies who just don’t care.  This home has renters coming in this coming Saturday, and the owners can’t figure out why every time the pool guys leaves after cleaning there is more sand in the pool then before he was there.  So they call him only to find he does not answer his phone, and his mail box can’t take any messages because its full.  So they call us and I go over and check a couple simple things to eliminate this and that.  I come to the conclusion that they have a broken lateral at the bottom of the sand filter.  Now they are perplexed since they just paid this company far to much to change the sand in a filter that seemed to run fine. How could this be they ask?  I simply respond by saying “well you can’t learn every thing from youtube.”  Here is a picture of the broken lateral