My stones keep turning black ?!?!? WHY?

[redjocks]

Despite frequent water changes and all-round healthy water conditions my stones have a dark look about them even just two days after a water change and by the end of the week are pretty black on the surface.

:help:

[ct-death]

New tank? Is it drk Brown vs. black? Does it wipe off easily? Also, do you get this on the glass surfaces also, and decorations?

If so, I would highly suspect Diatoms (Brown Algae) without knowning more about your situation. Harmless also, just looks ugly and needs to be cleaned weekly.

[redjocks]

New tank? Is it drk Brown vs. black? Does it wipe off easily? Also, do you get this on the glass surfaces also, and decorations?

If so, I would highly suspect Diatoms (Brown Algae) without knowning more about your situation. Harmless also, just looks ugly and needs to be cleaned weekly.
no it's not brown algae, my tank is well cycled and I have good water conditions. I change 30% weekly - but it's only the stones that ever look bad, water still nice and clear at end of the week

[ct-death]

Does it rub off? The rocks could be reacting to something in the water as well - What kind of rocks are these/Where did you get them?

What's your tank setup? ...and all of the other elements within your tank are not being altered?

Were the rocks locally collected and if so, cleaned properly and/or tested for suitability? Diing organisms will turn black (more common w/ "living rock" in saltwater environments, but...) Also, depending on 'where' they were collected chemicals or other compounds could reside on them.

Just hedging guesses until we find out more ;)

[Mgamer20o0]

i would guess algae. more info would help.

[redjocks]

My set up is that I have a 5 month old tank, 54L, with two small angel fish, 6 cardinals, 2 rummy nosed tetra, sword-tail, 3 male guppys, a young clown pleco and zebra loach... and a raphael. I only have fake plants and rocks that were sterilised before going in. I got my gravel from the store and that was washed too prior to adding to the tank.
Other than the stones all is well in my tank, healthy shiney fish, Pleco keeps it algae free and Raphael gobbles any food that hits the floor, PH and Gh levels are all good... but the dark groth is only on stones in the central area of my tank. Is it just from their waste? Could I be over feeding? (usually 2/3 times daily not too much at a time)

[Dangerdoll]

you're feeding too much and you have too many fish in your tank as well as some that are inappropriate for the size. Your tank is a 14ish gallon tank, which is just too small for the combo of fish in there. The angels, pleco, and even raphael need a bigger tank for sure. By these, I can see that your elements in the tank are sparking and supporting your algae growth.

[mellowvision]

that is massively overstocked.