Yellow stuff?

[Tommy McDonald]

I have this yellow stuff growing on my rock had high nitrate and nitrites so did a water change. But was wondering it it's good or bad doesn't seem to be hurting the fish

 

[Edward Stocker]

Might be a sponge, I've gotten random sponges before.

 

[Tommy McDonald]

But it's spreading like I leave for work in the morning come home it's almost double

 

[ndrwater]

Probably more likely a type of algae. Looks like a very new tank, and once the cycle starts to get going, so does the algae.
Perfectly normal.

 

[Tommy McDonald]

Probably more likely a type of algae. Looks like a very new tank, and once the cycle starts to get going, so does the algae.
Perfectly normal.

Yup tank month month in a half old, I had high nitrate and nitrite did a water change and the yellow stuff double over night pretty much

 

[ndrwater]

Pretty much the norm. All a part of establishing a new tank. Look at it this way, NOTHING wants to grow in a brand new tank. Especially one that hasn't even had a chance to establish beneficial bacteria. Once things start to settle down a bit, algae is often the first opportunist to start growing. Oftentimes like gangbusters.
Now the hard truth... Algae is something you will NEVER get past 100%. Either in the rocks, or glass. Part of the reason people often mention a CUC or "clean up crew" consisting of snails, crabs etc.
Stay on top of your regular small water changes using high quality water like RODI, and it'll be easy to keep under control.