Ceramics and High Silicate In Tank

[See Gee Sea]

Hello - I did an ICP test about 5 months ago since I've been battling what looks like diatoms for 18 months now. I can't confirm that without a microscope but it appears on my sand bed and glass in the daytime and dissipates at night. The ICP test showed my silicate level at 515 µg/l. I started running a GFO in a reactor which seemed to help but the phosphate went to near 0PPM and the nitrate went upward of 16PPM and my macro algae in the refugium started to bleach out - naturally. One thing the ICP test mentioned is that ceramics can cause high silicates. I do have the MarinePure ceramic balls in the bed of my refugium. Could this be what's been causing the issues? My RODI water is 0 TDS and the well I draw from has a TDS of 124. Before I buy a silicate test kit, I was just wondering if the ceramic balls could be the culprit.
Current values are Nitrate 12PPM and Phosphate .02.

 

[taricha]

Well water would have a bunch of Si too, and it's pretty hard to remove all of it.
So I'm not sure the ceramic (though possible) is the likeliest source.

 

[Randy Holmes-Farley Verified Community Expert]

I would not assume it is the ceramics, as many either do not contain silicate or do not dissolve.

Testing the RO/DI is a good plan. Silicate can be hard to bind.