Rusty Coloured Ocean Rock

[SensesFail]

Hi i took a glance into my aquarium tonight and yesterday the ocean rocks were nice and shiney with nothing on them at all. When i looked today they have what i can best describe as rust looking coloration on them. So i dashed for the test kit and the results are as follow:

Ammonia 0 (Strangely in my living room light with down lighters its 0 and in the kitchen under the florescent under bench light it looks like 0.25!) Iv always gone off the living room.
Nitrate = 30-40PPM
Nitrite = 0

I have included a pic below seems to be on the rocks and a fake cave i have. Pic is taken with my mobile but gives you the idea, what is it??

Cheers Guys

Rock

 

[anon02]

Looks like diatoms, how long do you have your lights on

General consensus is that it`s harmless and goes away as your tank matures

 

[jonathand]

No idea what it is, looks like some sort of growth? but I can explain the light.

Most florescent and energy saving bulbs give off light in the higher colour temperature range (blue) so when you look at yellow it appears green!

 

[SensesFail]

Looks like diatoms, how long do you have your lights on

General consensus is that it`s harmless and goes away as your tank matures

I have the lights on from 4pm till 11pm then rely on natural light which does not hit the tank direct. will be a task cleaning the ricks if this has to be done