Diatoms in the aquarium

My aquarium (75g) has been having issues with Diatoms (brown algae). It’s been ongoing almost since I set it up 11 months ago. I’ve been reading about diatoms and now I’m a bit confused. I was reading that adding more light can create the green algae which will compete with the brown algae. Now I’m not sure if my tank is now getting TOO much light.. or not enough. It’s in my living room and while it does not get direct sunlight it IS close to a window so IS getting indirect sunlight. I’ve tried going for periods of time where I didn’t turn the tank light on at all..hoping that would help but it didn’t se to make a difference.. now I’m at the point where I turn it on for maybe 3 hrs in the evening until I go to bed. What I’m getting at is I’m not sure if the tank is perhaps NOT getting enough light or is it getting top much? I’m not sure if perhaps I should be turning the light on for longer periods or not. Thoughts?
All parameters are within normal ranges.
Also to add.. relocating the tank is not an option.. this wall is the only wall I can put it on

 

Diatoms feed on silicates. Find the food and get rid of it.

 

I can’t imagine what the source is though.. I can’t possibly be over feeding.. I feed every 2-3 days as it is.. I feel like I’m starving my fish.
I don’t want to turn the light on longer in case that’s the source and I cause it to get worse. Everywhere I read says it’s a common *new tank* thing but this tank is 1 yr old in sept.
I’ve tried using silicate remover media in my filter and even that isn’t helping.

 

Sources of silicates are:
Water Source
Play Sand
Any Sand and rock substrate, especially the pretty stuff
Plastic decorations and plants

 

My aquarium (75g) has been having issues with Diatoms (brown algae). It’s been ongoing almost since I set it up 11 months ago. I’ve been reading about diatoms and now I’m a bit confused. I was reading that adding more light can create the green algae which will compete with the brown algae. Now I’m not sure if my tank is now getting TOO much light.. or not enough. It’s in my living room and while it does not get direct sunlight it IS close to a window so IS getting indirect sunlight. I’ve tried going for periods of time where I didn’t turn the tank light on at all..hoping that would help but it didn’t se to make a difference.. now I’m at the point where I turn it on for maybe 3 hrs in the evening until I go to bed. What I’m getting at is I’m not sure if the tank is perhaps NOT getting enough light or is it getting top much? I’m not sure if perhaps I should be turning the light on for longer periods or not. Thoughts?
All parameters are within normal ranges.
Also to add.. relocating the tank is not an option.. this wall is the only wall I can put it on

Found the source... it was the pool sand I’ve been using. I switched it out )big job!) for actual aquarium sand and haven’t had an issue since *knock on wood*