# What causes a diatom bloom?



## willieturnip (Aug 30, 2009)

As a new tank matures, a diatom bloom is more than likely to occur. But why exactly?


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## wake49 (Jul 2, 2008)

Everyone says that excess Silicates in the water are the reason for Diatoms. The Diatoms use Silicates to form their shell much as SPS corals use calcium to form theirs.

Since their is no real reason that Silicates would be in the aquarium at only the beginning of the tank's life, it's more likely that DOC's (dissolved organic compounds) and Nitrites are the cause for Diatoms. This would be the point when the Nitrite reading is high but Nitrates are still undetectable. 

I have read in the past that Diatoms are actually beneficial for a tank, as a good algae. The reason was that Diatoms consume a lot of the same nutrients as other nuisance algaes, but are easier to clean from the glass. The author of that blog (which I can't find, but will post it if I can) used "water glass", which is some kind of liquid silicate to promote diatom growth. 

Either way, algae will always be present in some form in the aquarium. I personally use Macroalgae in my sump, to feed on the nutrients and starve the nuisance algaes.


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