To do with old live rock?

[MTF7]

Ok I am restarting my tank that recently got nem-a-nuked and I have a question about what I can do with the rock.
My rock has HA on it in quite a bit of places and has a little of that red slime crayo something I can't remember the name right now but I was wondering if I could remove the rock as scrub the HA and red stuff off of it or will this mess up the existing bacteria my tank has not had flow through it for about 3 months now just stagnant water so this is why I am completely restarting

[zakstrong]

If the water has been stagnant for that long chances are the bacteria you have isnt the kind you want. I would take out all rock and do fresh water scrubs and dips. use something with STIFF bristles. Remove all sand and replace with dry sand. Replace it with a bigger grain of sand, easier to clean in the future and better at moving oxygen to the bottom.

Put all the rock back and fill her up. There will still be considerable die off so I would plan 30% changes once a week for a month. If the algae bloom isnt bad then adjust accordingly.

also clean all equipment. skimmer etc.

If it is an option you might let everything dry entirely, rock included. That might help with algae blooms

[MTF7]

Already started it I did brush all the algae off and stuff but I didn't really think about it and I put the rock back into my tank and my ammonia was high from the left over unreached sluge from the old tank and I think it was like I'm not sure but like 5.0 so really high and i checked the next day and it was around 2.5ppm. So as of now I have no ammonia no nitrate not phosphate no nitrates nothing I have 12 Astraea snails 3 narrassis snails and 5 hermits and I just put I'm my first coral ( even tho I don't have any fish yet and I wasn't going to do coral for awhile but it's green star polyp frag that I got for free so not gonna pass on it and I thought it would give it a head start on being my back on my BC29) but yea it's going really well