Can anyone explain why these white stones turning brown? Is it some kind of algae?
This is probably brown algae growing on your stones. If you have any Nerite snails or Mystery snails, you can try to use them to cleanup the rocks. Good luck!
That's the good stuff. You've got a nicely seasoned tank there. Most small fish will pick at it, nothing I'd worry about
I have oscar and pirhana
That's awesome. We can't keep them here, just pacus. Nice Oscar too
Is that.... an OSCAR and a black skirt in a 5-2.5 gallon tank???? You realize that Oscars get 10-11 inches, meaning it'll need a 55 gallon full grown. The black skirt might even become a snack. You have SERIOUS stocking problems if you'd like to let us help you.
What if the oscar and piranha are really big and in a large tank with a massive internal filter? What if? What if the stones are really big? Maybe the camera is making everything look small
Looks like diatoms algae that show up in almost every new tank. Any snail and amano shrimp will eat them. Or you can wash them you yourself.
I see. That is good to know. XD You have no idea how many friends have sent me pics of small tanks with oscars. They see them at stores when they're small, and most people don't know how big they get. Obviously I overreacted. It's nice to know that someone knows how to properly care for them. Also, that piranha REALLY looks like a black skirt. Especially with the lighting. That's pretty cool.
I have 45 gallon tak
to small , an Oscar requires a minimum of 75g all to himself. They get to 12" and in a 45g which is 13" wide won't be able to even turn. can't speak for the piranha , as I've never kept them but I do no they can get pretty large but regarding your questions its diatoms , it grows in almost all new tanks , you can just scrub the rock, it's completely harmless.