can anyone help me identify what's going on here?

[reef4Tom]

I have used a very little amount of Kent Marine "Purple Tech" to help promote the coralline algae growth in my newer tank. Sorry, I don't have a whole lot of other info.

Tank specs:
75 Gall
9 fish
3 shrimp
a few hermits
a few snails

 

[Rutrag]

That looks to be typical Cyanobacteria, sometimes called red slime. What is your water source (RODI, tap, LFS, etc)? It tends to like nitrates, phosphates, and low flow. What do you have for circulation in the tank?

 

[reef4Tom]

I use RODI water. My flow is questionable. I have a jebao wp-10. I have it on a "medium" setting as anything higher seemed to stir up the sand. I have another power head rated for a 75-100 gallon tank (don't know the specific flow). I don't have that in the tank for the same reason regarding the sand. I have questioned if the tank has enough flow.
side note, I have a HOB skimmer/fuge. (I'm a low budget beginner)

 

[Rutrag]

I'd definitely up the flow. My 75 I recently upgraded to a 90, and I used a WP40 and two Koralia 1050s for flow. I would double check phosphates and nitrates, and up the flow first. If that doesn't make it go away, you might consider Chemiclean, but that's only a band-aid. If you don't eliminate the underlying problem (nutrients or flow generally), it will come back.

 

[reef4Tom]

I'd definitely up the flow. My 75 I recently upgraded to a 90, and I used a WP40 and two Koralia 1050s for flow. I would double check phosphates and nitrates, and up the flow first. If that doesn't make it go away, you might consider Chemiclean, but that's only a band-aid. If you don't eliminate the underlying problem (nutrients or flow generally), it will come back.

Thank you for the advice. I'll definitely make the adjustments.