What causes “ugly stage” in reef tank?

[Miami Reef]

Added new live sand and bleached live rock to my tank. I am aware that I’m going to go through an “ugly stage”

but I want to know what causes it. Algae cannot grow without light and nutrients.

a few months ago I added uncured rocks to my established tank and got a huge algae outbreak. Phosphates and nitrates were 0 though.

 

[tbrown]

Most likely you had an ammonia spike. If your rock had no bacteria to convert nitrite and ammonia to nitrates, your nitrates would be zero. Phosphates could have been 0 depending on your source water and salt especially if you weren't feeding anything yet.

 

[Miami Reef]

That makes sense because I did test small ammonia. Is it possible the ammonia fueled the algae? I always thought algae needs either nitrates or phosphates

 

[monkeyCmonkeyDo]

Swings in water chemistry. Low flow. In adequet filtration. No small wcs during or after initial cycle. Whatever that initial cycle may be.
My opinions.
D

 

[Azedenkae]

That makes sense because I did test small ammonia. Is it possible the ammonia fueled the algae? I always thought algae needs either nitrates or phosphates

Don't forget the reverse would also be true. Algae needs nitrates and phosphates, but growth of algae actually depletes them too. So if you see heaps of algae growth, that could also be the reason why you are reading 0 nitrates/phosphates.

 

[MaxTremors]

It’s usually diatoms which are caused by silicates. Also, when using dry rock, bacteria and various forms of algae, and eventually coralline algae are all battling it out for space, so in the beginning, whatever can out compete the others will take hold. But as your cycle and your params level out and your nutrient export gets stable, coralline algae should take over. Also, how are you nitrates zero if you just cycled the tank? Were you adding food or ammonia? If not, then it’s not cycled, and if you were, it’s maybe not done yet if the ammonia isn’t converting to nitrite and then nitrate.

 

[Miami Reef]

The tank was cycled, but I wanted to redo the rocks so I put all the rocks outside the tank for 30-45 minutes. A week later I bought some rocks from LFS that were in water but know some of them weren’t cycled because they were pure white.

Plus I added a lot livestock. It all makes sense why the tank crashed.