Need help I.D. This thick algae

[Gary LeCompte]

This thick algae is only in 2 spots in my DT. When I do a water change I suck it out and it comes back.
My Water is as follows.
PH-8.16
Alk.-8.96
Calcium-420
Mag.-1230
Nitrate-5
Phosphate-.1
Salinity 1.026
Any suggestions as how to handle this.

 

[Bret Brinkmann]

Looks like cyanobacteria. Most people get it when some food goes uneaten. Manual removal and review your feeding to see if you can tell if any goes uneaten so you can scale back or feed more frequently but smaller amounts to reduce wasted food. It also likes lower flow areas of the tank. The local flow rate in that spot does look like it would be less than the rest of the tank. You can also try to increase flow in that spot.