Brown sand

[guitareefs]

My 300 has been clean for a very long time....meaning sand has always been cleaned and white. Not much debris on the sand bed....that is until i put kessil a360ws on my tank. Up until 4 weeks ago, ive had low light leds. Was fish only. Since i put my kessils on, the sand has turned brown.

Questions:

Is it diatoms?

Should i vacuum it out during next water change?

 

[BigJim]

It looks like diatoms that are likely thriving under the higher light. I have high silica in my tap water and have the same issue when my di resin is no longer removing silica. It still shows 0 tds on my tds meter, but an icp year confirmed high silica in my rodi water. I now use the spectrapure silica buster in my second di stage to fix the issue.

 

[RICKY81]

are you able to decrease the intensity of the lights? It might just be that the lights are too strong initially.