Just starting

[adamcollins]

Hi i have had a 125litre/30g tank running for a couple of weeks i have a fluval 205 external filter all set up and i have a skimmer as well, i have placed 15kg of lR (which is cured) into the tank with on average 2.5 inches of sand throughout the tank,
with all this up and running with 120litre of salt water which i bought from the shop i decided to get a very small clown fish and a shrimp,,, over the last few days large amounts of live rock have almost gone a rusty colour is this normal? but when i did my water change where the water fell on the rock the rust colour came off its almost alge do i want this??????????
i have checked that my external is working and my skimmer has bubbles in the cup (if you know what i mean), am i doing any thing wrong,
I'm planning on having fish coral and live rock in the tank, i know my lights are up to it yet as i have ordered T5 but i thought this wouldnt make tht much difference as i dont have coral in the tank yet, would this create the rust colour on my tank

 

[mr_x]

it's either brown diatom algae, or cyanobacteria. the brown diatom algae is completely normal and is present in every brand new tank. it will go away on it's own.
cyanobacteria however, is from excess nutrients in the water. it could be from die off on the alleged "cured rock", or it could be from adding too much fish food, too soon. this comes off the rock easily with current. this is why i think it might be cyano. i don't think brown diatom algae is easily removed like you are saying.
i think the rock needs some further curing. i also think the addition of livestock was a bit premature.
do you have test kits to test for ammonia, nitrite, and nitrate? if not, i think you should get them. if so, what are the readings?

 

[adamcollins]

hi yeah i have a test kit all the readings are fine apart from my nitrate is the lightest pick you could imagine, when i found this out i went to the shop and bought salt water and did a 20% water chnage which i was told to do...
if it is cyano do you know the best way to get rid of it or shall i leave it to get removed on its own

 

[mr_x]

if it's cyano, i would do a waterchange while vacuuming it off of the rock. then increase flow and keep the waterchanges on a regular schedule. cyano is brought on by excess nutrients.