White feather pattern on back glass

[apaudet]

Does anyone know what this white feathery pattern is on the back of the main display? I noticed this the day after a 25% water change on a 25 gallon AIO.

I’ve been battling Dino’s for about a year and a half on and off. Nitrate was 43.0ppm and phosphate 0.11ppm before water change and Dino’s were almost gone and came back a little bit after the water change due to new trace elements but I have no idea what this is.

 

[Crabs McJones]

Snail eggs

 

[rtparty]

Nassarius snail eggs

 

[apaudet]

Dang, that’s the only snail I have in there at the moment, thank you both!