Whats Growing in my Sump?

[goldhopper]

My 220 Gallon tank is about 6 months old and all the water paramters are great (Nitrites 0, Nitrates 0, Phophates 0, PH - 8.1, Calcium 470, etc.etc.). I am new at this and built everything myself with a lot of research and asking a lot of questions. I have a little Brown algae but that is gone and no other algae outbreaks. The 100 gallon (60 gallons of saltwater) sump is below the tank in the basement and automatically does a water change every night with 5 gallons emptied and 5 gallons refilled. I noticed about a week ago that there is little fatty deposits in the Sump where the tank empties into and in the Return section. I recently added a UV sterilizer but I do not think that is causing the problem although I could be wrong. Does anyone know what these little fatty deposits are and what to do about it? They come off very easily. Happily none of these are in the return section or the Refugium. Also, does anyone have an idea how I can clean the PVC of these fatty deposits and algae. There is no easy way to get to the PVC. Thanks

[Floowid]

Kind of look like pineapple sponges to me. If so, they are good, not bad.

[mcgyvr]

yep.. Pineapple sponges.. VERY common..VERY harmless.. beneficial filter feeders.. Their population seems to explode in a new tank then it seems to subside a bit..

and as always.. This site here is a good read/scan for all newbies as it covers/contains most of the stuff that pops up in our tanks..
https://www.lionfishlair.com/hitchhikers-guide/
I'd HIGHLY suggest looking through it and even bookmarking it..

[Mendozasreef]

Good answers.. thanks... always wondered what that stuff was..I have lots in my sump.