Im new to the fish world and have recently set up a 90L tank with a single damsel. Ive run my cycle and all ph, nitrate, etc have come back fine. Im looking at doing the nemo thing blahblah but am starting to worry as the rocks in my tank are starting to change colour. What once was greyish is now brown. Is this normal???? Save my sanity please. :oops:

May be algae growth

myself and jetskisteve are suffering the same thing on the substrate though, sand is covered in the shit. steve reckons "it's just that time of the year, it comes and it goes". i'm a little more concerned though... send pies or jetskisteve a PM and they'll tell you what it is.

If you have a marine tank, I suggest you post this in the marine section. The reefers there will be great help.

Welcome to the fishroom by the way.

it's probably that your phosphates are too high.

oh yeah, and caryl's right, you'll get a better response in there!

Some more information would be usefull. Forexample you say your PH/nitrate have come back fine. What have the came back from? What are they now?

I suspect your are still cycling, can take over 3 months if you used dead rock to start that tank off, I assume you did because you said the rock 'was' grey.

The brown growth is almost definatly Diatoms. A very common type of brown filmy algae. Normal, not a problem and no need to loose your sanity.

Phosphates? Possilbe, but unlikley to be the major contributor in this case. Lets talk about DOC (Disolved Organic Content). Are you running a protein skimmer on your tank? If you are great! If not, start saving...

Water changes? Water topup. Are you doing water changes? By this I mean taking saltwater out and putting saltwater back in? If yes, good! If no, then this is something that needs to be done often. I would suggest that because the tank is only 90L, try and do 20L ever 2 weeks or so. Evaporation? Do you know that you need to replace water evaporation with freshwater not saltwater?

Are you measuring your Specific Gravity? If so, good! Keep it between .022 and .027. Really doesn't matter a great deal which, however keeping it stabe is very important.

I see your in Auckland. Perhapps pop over to one of the 'teams' house 1 day and have a chat with them, I am sure they can answer all your questions and concerns, and its so much easier to chat than it is to type!

Good luck to you.

Pies