Foam in sump

[MrSculpin]

I have what looks like white "foam" in my sump.
its in the return section and covers say about a third of the water surface. Not sure what is causing it really. Just did a water change the first part of this week, water tests good.
0 ammonia, nitrates and nitrites. ph is 8.2
sal 1.024
everything seems good.

We were gone this last weekend, had my dad come feed the tank. I noticed the hair algae exploded and lots of Aiptasia when we got back.

I thought that was due to the lights not being on as much, and his feeding more perhaps.
We were only gone three days.

 

[estanoche]

My vote, some sorta protein buildup - do a quick water change and see if that reduces the foam level. Its possible your nitrates aren't testing right, or they haven't spiked yet

 

[returnofsid]

Do you have a protein skimmer? If so, is it working correctly and does the collection cup need to be emptied? Sounds like protein built up. If you've ever been to the ocean, you've probably noticed the foamy scum that collects at the water's edge. This is nature's protein skimmer. You're protein is collecting where the flow is pushing it.

 

[MrSculpin]

I think the protein skimmer wasn't working correctly. While the cup wasn't full, only had about an inch in it. It didn't seem to be working. I did a small water change and cleaned out the skimmer and the foam seems gone. Hopefully that was all it was.