Best clean up crew for aggressive tank?

[CH3RRY]

I am starting my 300g off with a clown trigger, emperor angel, harlequin tusk, tesselata eel and maybe a shark.

Currently have diatoms everywhere.
already have used phosguard for 5 days, no results yet.
Best way to remove diatoms?
Main question- best cleanup crew for this aggressive tank - already getting 2 long spine urchins
Thanks

 

[Jason_MrFrags]

GFO for diatoms, you can also black out the tank for a day to help. Good skimmer and some oversize hermits

 

[CH3RRY]

GFO for diatoms, you can also black out the tank for a day to help. Good skimmer and some oversize hermits

I have a Red Sea 300 in this tank and a Red Sea 900 in my Red Sea tank. Both just fill up with water within 2min. Used to work fine but can’t find a fix