Every day something new

[cyn5351]

Yesterday noticed a bit of rust colored on top of the aquarium sand. this morning almost all of the live rock is covered with the stuff. see the pictures below. is this diatoms? is this something should I clean? Is it life threatening? it is their medication?
Lost a little clown fish today but I think it had been not doing well for several days. PRETTY BUMMED.
Just did a 25% water change on friday.
Tank is live rock and livestock. No coral
ammonia is 0.
Ph is 8.4 range.
Temp is 77

Used my own water with reef instant ocean. Boiled all the water for 20 minutes 1st to remove all trace of ammonia.
Should I clean thr rocks and sand then do another water change. Use water from LFS?

 

[BighohoReef]

Did you test for nitrates and nitrites?

Algae and detritus build up it's normal especially as your tank is exposed to more light and bacteria breaks things down in your tank... You could try increasing the flow, reducing your red and white lights can help as well. Leave the rocks in your tank you can use a baster/or spot feeder to blow off the rock, vacuum out the detritus as part of your normal water change, replace the water with clean RODI water from your LFS or get a RODI to make your own!

Do you have a clean up crew? snails, crabs to help reduce the algae?

As you can see from my tank I have the brown uglies going on right now as well. Clean up crew from @reefcleaners will be here to help with it on Thursday