Advice on Toadstool

[Bume]

Would you all wonderful reefers give me some advice? I've grown this absolute unit of a toadstool, from about the size of a golf ball to this monstrosity. When fully extended, it touches both the front and the back of my tank and I need to do something with it. I've bought a scalpel to frag it and watched a lot of videos on trimming them. I cant get it out of the tank without cutting it at the base and have mulled around with the idea of trimming it in the tank but I'm concerned about toxins if I do that. I've watched a video of a reefer doing both without ill effect on their tank and I'd like to be as unobtrusive to my system as possible, while still keeping the coral.

It measures about 12x14 inches when closed and probably 14x18 or so... when fully extended.

Can I trim it in the tank or should I take it out?
Could I get away with trimming a small amount every few months or should I do one large trim all at once?
Is there anything else or a different strategy I'm not thinking of?

Any advice is welcome, thanks for your time!

 

[dank reefer]

You can trim in the tank, but would suggest to run some carbon afterwards.

 

[blaxsun]

Nice toadstool.

 

[Reefing Madness]

I'd take it out of the tank, trim what you want all at same time, and still run carbon on the tank when you put it back in. It releases toxins into the water when you cut it up

 

[Beefyreefy]

I have one that size or bigger, and I’ve always cut it in the tank. No issues, no problems and I don’t generally run carbon. I don’t believe neon green leathers are all that toxic to other critters.