What is this growing in my tank?

[BrackishAqua]

Last month i switched over my 75 gallon into a 125 gallon. 275lbs aragonite sand 100lbs base rock. used the same overflow tank filters and such so there was only a mini cycle for 6 days. I added the fish and they love the new space. Had a nice diatom bloom and that has since subsided, but this morning there were circles everywhere growing through the diatoms. Heres a picture of one in the sand bed, same exact thing all over the base rock. what could it be? my sg is 1.013 ph 8.2 nitrate 80ppm i just recently got the phosphates down to around .5ppm with rowaphos. I use tap water with prime and instant ocean salt.

 

[Gavinpop1235]

That is I think nitrogen waste products often produced from life in deep sand beds but I'm confused are you talking about the gas bubbles in the sand or that white circle in the sand

 

[BrackishAqua]

Yeah the bubbles are just gas pockets. Im referring to the white circle. They just popped up this morning 1 in the sand and like 30 all over my base rocks

 

[Gavinpop1235]

Could be a lack of nutrients in that area

 

[BrackishAqua]

Definitely not a lack as my tank is booming with nutrients. Only thing i can imagine it being is coralline algae. Ill have to wait and see if any color starts to form. Woke up this morning to a bunch more circles all over the rocks.