Seeding options to kickstart diatom population?

[Obriy]

I've been fighting with SCA for around three months already. Silica levels have been between 3 and 11 for almost two month, but diatoms are barely visible and it's always one type.
Are there ways to seed my tank with other types of diatoms with hope that they have more success in overtaking SCA?

 

[Rocks reef]

Are you dosing silicate?
What are your NO3 and PO4?

 

[Obriy]

Are you dosing silicate?
What are your NO3 and PO4?

Yes, I'm dosing silicate, forgot to mention. NO3 around 10, PO4 around 0.07.