Diatoms how do I get rid of it?

I have had my 55 gallon freshwater tank for about a year now and for as long as I can remember I have always had a Diatom Outbreak no matter how many water changes and glass scrapes I do the Diatoms are just covering every inch of my tank within a few days of cleaning.
I perform weekly 50-70% Water changes with the gravel vac. And use a magnetic algae scraper every few days. The tank lights are on a timer set to about 9hours each day.
The tank is home to a Tiger Oscar, Jack Dempsey, Peacock Cichlid, and a Firemouth Cichlid.
I would appreciate any help with getting rid of the diatoms or at least reducing them, they make my tank look gross and neglected.

 

With those fish I'm guessing it's not a planted tank? Any reason that you have the light on for 9 hours?

 

With those fish I'm guessing it's not a planted tank? Any reason that you have the light on for 9 hours?

There is some hornwort but other than that just fake plants, I just have the lights run from noon to 9pm should I reduce the time they’re on?

 

It's worth a try. I don't have much experience battling diatoms, it's usually something that plagues new tanks. But I suspect that the length of light may have something to do with it. In the absence of plants algae is likely to take advantage of it.

 

I've had similar trouble. I'd been backing off on the lighter timer, and it didn't do a lot. Then I finally made a last-ditch effort and reset the timer to eight hours, and it made a significant difference. There are lots of factors that can be involved, but when I backed off the lighting to a very minimum it helped a lot.

 

Not to be the tank police but your tank is not big enough for all those fish. Especially an oscar. But as for the algea it might be your lighting. if you don't have plants then 8 hours is fine. What kind of light do you have? If its super bright, try something with less intensity. cichlids don't need a lot of light. And bright light with no plants to compete with it will cause algea because it has all the light to itself.

 

What seems to work for me when I get diatoms is thorough gravel vacuum every week (I purposefully use a vac meant for a nano tank for this so I can take my time). More than lights or reducing ferts, I look at water flow, make sure as much of the water is churning, doesn't have to blast them across the tank, but a gentle churn just so the water is moving everywhere all the time seems to help immensely.

 

Check for phosphates in your water. If they are over .25ppm it will encourage the diatom growth