you need more tests...calcium, phosphate, oxygen, strontium, magnesium, ph..my experience is you need all these levels right..or within reason..your correct mushrooms and zoas are hardy and if they died, somethings wrong, after 6 wks you finished your cycle..and you said you did water changes so thats good..if all your levels are good then its a problem with your system..your pump needs to circulate the water 7 times an hour , it may have been your lighting, i saw you ordered new lights sooo problem solved..i def recomend getting a fish. damzels suck bc theyre not very friendly...but theyre only $4 ..so if they die...thats not good but its not the same as losing a $50 fish..
ohh...dont add too much iodine..i just had a problem with that ...i was adding all the norms..mag, cal, trace, potas, and....iodine...and my mushrooms were looking huge and then one day they shriveled up and looked terrible..i read a bunch of posts and read that adding iodine wil nuke your tank...so i did a cpl water changes, stopped the iodine and theyre starting to look good again..
good luck