Toadstool leather help (parasite?)

[dan’s tanks]

So I bought a toadstool leather a couple of months ago, and it was doing great. Polyp extension from day 1, shedding monthly, growing.
About a month ago, I started having some bad cyano blooms (mostly due to powerhead cutting out + high nutrients)
I’ve been battling this with water changes, newer Powerheads, and I even tried Gfo for like a day (some of it went through the mesh bag and got into the display, very little though)
My toadstool leather started wilting as the cyano grew, and has been doing so for about a month. I noticed today that the trunk was ripped, and it kinda looks like it might be hollow on the inside.
I’ve read about a certain snail that lives inside of leather corals and eats a hollow pocket, but that kinda sounds outlandish, so if anyone could offer me any suggestions as to what could’ve caused the ripping, please help out!

tank is stocked with plating sponge, leptosteris, chalices, gorgonian, a RFA, zoas and mushrooms.
Fish are 2 clownfish, 1 small kole tang, 2 barred gobies, a carpenter flasher wrass.
Snails are 1 fighting conch, some algae eating ones (astrea?), and some bass around snails. Got some hermit crabs that used to be a problem (ate a dying Duncan head) but I have never seen them express interest in my toadstool.
Thanks so much (tank is 75g)

 

[Subsea]

Exposed flesh is white, what is the darker patch. Was Cynobacteria on the leather?

 

[dan’s tanks]

Exposed flesh is white, what is the darker patch. Was Cynobacteria on the leather?

Yes, I’ve been blowing the cyno bacteria off the trunk. The polyps have been coming out, it just seems the base is unhappy

 

[Mr. Mojo Rising]

What kind of flow do you have? Looks like green algae and cyano is growing on the stem, it gives me the impression of low flow.

 

[dan’s tanks]

What kind of flow do you have? Looks like green algae and cyano is growing on the stem, it gives me the impression of low flow.

My powerheads were slowly breaking so I had very little flow. I just got a new powerhead so I have a lot of flow (for the past couple of days). Could that have caused the stem to rip?

 

[Mr. Mojo Rising]

It think that’s part of the problem, if not the problem. Leathers like flow, they need flow to help them shed. If they don’t shed, algae grows on them. You can use a turkey blaster to blow it off, hopefully it’s not too late.