Brown diatoms going nuts

[Mical]

I'm suspecting you're getting silicates from the food you are feeding. Some pellet foods have traces of silicates and I've heard some frozen "off brands" are rinsed in regular tap water. All the above suggestions are good but if you have a decent TDS meter and your RODI is close to 0, there is another source of silicates getting in somehow.

 

[Lowefx]

It's been gone since I added a gobie sand sifter. An I raised nutrients temporarily