Tenant requests tub resurface, but it's soap scum. Who pays $175?

[Jeff T.]

Tenants asked to resurface tub but it turned out to be soap scum. Should I charge them back for the $175 cost?

The long term tenants asked to have the tub resurfaced after I increased the rent (up from way below market to 15% below). They have been good tenants and haven't asked for anything until I switched PMs and they raised the rent.

I got this note from my PM after the tenant requested the tub to be resurfaced. I'm paraphrasing parts of it.

"After our recent visit to the property the bath tub  looked to be worn and needed to be re finished.

The vendor used to do this scheduled with the tenants to have this completed, however we received a call from their office whilst their tech was onsite and they mentioned that the tub did not need to be refinished. What was initially thought to be worn surface paint was in fact a build up of soap scum. The tech was able to get the tub clean and looking good.

We have received the final invoice from the vendor and the total amount came $175.00. What I wanted to find out from you if you are okay to leave the bill as is or if you would prefer for us to charge it back to the tenants? "

I'm inclined to charge the tenants as it was just cleaning that was needed and they asked for it, but I wanted to hear from some experienced people out there.