I added a 20 gallon refugium to my 139 gallon system 3 weeks ago. Installed a Kessil H380 and a softball size of Chaeto. The Chaeto has been getting quite lose and turning brown, it easily falls apart. Diatoms are growing on the floor and walls of the refugium like crazy, much less diatoms in the display. I know I have some silicates in my RO system and a new filter will be here tomorrow, otherwise water tests pretty good. Phosphate is 0.03 and Nitrate is about 8ppm. Added the refugium and the Kessil to get the Nitrates down. Will the diatoms kill Chaeto? Are my nutrients not high enough to support the Chaeto? Any help or suggestions are greatly appreciated.