White fur algae & UNKNOWN large White “polyp?” HELP

[Clownfishernoob]

Hi.
I have a converted 29 gallon biocube, started new 6 months ago with dry substrate and “dry” rock from my previous 150 gallon tank setup.

The tank has gone through the brown algae stage, and has now began growing a white, fur type of algae on the rocks and surfaces.

I have never seen this type of algae grow in my previous tanks, nor can I find a solid answer as to what it is. I have seen an interesting theory about using wax burners inside the house, and considering the conversion of this tank is open top style, maybe that is possible. We have discontinued use of candles or
Wax burners entirely as yesterday.

The other question is about the single large Polyp style growth that has grown with the white fungus or algae mentioned above.

I have no idea what it is, or how to treat it.

I have included pictures of all.

I use a 3 decker filtration starting with floss in top, chemipure blue in the middle, and submerged in the lowest level-Purigen.

Next there is a macroalgae refugium with the seaweed and it’s own lighting.

I change 2-5 gallons of water a week, and the actual water capacity is 21 gallons.
I also have a biocube, wooden block protein skimmer that is not needed or much use. but there.

I have included pictures.

thanks for help or information from anyone!

 

[tbrown]

The white thing is a sponge, pineapple I believe.

 

[tbrown]

The "fur" is probably a bacterial bloom.

 

[JGT]

Pineapple sponge, filter feeder, harmless.