Yellow residue ?!

[Dallz]

I've had a yellowish residue on the bottom of my pool, it's in patches all over...I tried to vacuum it and it's back the next day. Is it the start of an algae outbreak? I've never had one so need to ask!
If so, should I slam tonight ?

Also after vaumming I made sure to backwash and rinse in case it's Algae. Will that help?

Thanks!

 

[JoyfulNoise]

Can you post your latest test results? You should definitely perform and overnight chlorine loss test to see how much FC you're losing overnight. Sounds like it could be mustard algae....