"Mean_Chlorine" wrote in message No.
While it is true that very small amounts of silica will leach from the
sand and from the glass, diatoms are very, very, rarely limited by
silicates in coastal seawater, and virtually never in freshwater.
Unless your aquarium is using nothing but pure RO, they're not going
to be silica limited, and any addition of silica will make no
difference at all.

Also I might point out that there are basically two types of sand one
might use in aquaria: there's carbonated-based sand (limestone), which
buffers pH to 7.5-7.7, and there's silicate-based sand which is almost
entirely inert, does not affect pH, but does leak trace amounts of
silica. Silicate-based sands are by far the most common in freshwater
aquaria.



A agree with MC on this. I have a Tanganyika tank with beach sand that is
renowned for high silicates and I have zero algae problems with this setup.
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**So long, and thanks for all the fish!**