Tiny white string on decor?

Hi, everyone! I have two seemingly new things going on in the tank.

1. Yesterday, I replaced my rock wall (resin) with bubbler with a new one. Same item just swapped it out. The old was was really starting to look bad. I rinsed the new one thoroughly. A few hours after putting it in, I noticed tiny white strings on it. Just at the top really. Not fuzzy. Not web like. Just a half-inch really thin white string- or thread-like something.

2. This of course got me staring at the tank and now I notice a thin white haze on the inside of the glass. This is not normal for the tank.

See photos attached. Other info:

• 20 Gallon high tank
• The new rock wall went in about the same time I added a new Serpae Tetra to replace one lost last week.
• Total stock in tank is now 5 Serpae Tetra and five live plants (various/unknown).
• Fish seem fine but the are on the pale side lately. Plants...some do great, one starting to yellow.
• Last water change: 9/24 (just 10%)
• Ammonia: 0 ppm
• pH: 7.0-7.5
• Nitrite: 0 ppm
• Nitrate: 40ppm
• GH: 180
• KH: 80
• All of the above readings are in line with recent data points for the tank.

I guess I'll do another water change today and try to sponge the inside. Was thinking of taking the wall out and wiping/rinsing again.

Appreciate any thoughts!

 

Looks like Staghorn algae to me. I would take it out and give it a dose of peroxide. You may have to repeat but that is what has worked for me.

 

It might be bits of sponge/scouring pad from when you wiped it down.
Maybe not, but it's happened to me. Filament gets stuck in the crevices.

 

Looks like Staghorn algae to me. I would take it out and give it a dose of peroxide. You may have to repeat but that is what has worked for me.

I think that may be it. Took it out. Scrubbed it down. Did a 12.5% water change. Overall things look better, but some string remains.

 

I think that may be it. Took it out. Scrubbed it down. Did a 12.5% water change. Overall things look better, but some string remains.

If you didnt do the peroxide it will come back. It will turn pink.

 

If you didnt do the peroxide it will come back. It will turn pink.

I poured peroxide on the spots it was on. Then soaked a cloth in it and scrubbed. Hopefully that kills the pieces that didn't come off. I didn't soak it in a peroxide solution, though... and perhaps I should have?