Thanks, all. I thought higher temps might deter this scourge, but it appears they grow at any temp
A couple of months ago, I got my three new tanks and stands. The 28g in particular had quite a bit of the stuff, so before adding the rock to the new 37g, I scraped it all off the rock, rinsed the rock in old tank water, then set the new tank up.
Last week, the bubble algae had gotten so bad again in the 37g, I tore down the tank for more scraping and rinsing. Then I realized that I had done that before with dubious results. There had to be thousands of bubbles all over the rock, I kid you not
So, to REALLY get rid of this evil stuff, I soaked the rock in tapwater overnight after all the scraping, then placed the rock in boiling tapwater the next morning. When the rock cooled a bit, I scraped and brushed the rock clean in a sink full of more hot tapwater. This totally killed the rock, needless to say, but I was totally desparate to rid my tank of this tenacious algae
The dead rock is in a 20g with NSW, and is curing. I expect the stench to take at least a couple of months before it goes away so it can be used in the 37g again. Corals, mostly lps, are in the 37g also with NSW. Oh, yeah, I super cleaned the heaters, powerheads and tank in tapwater too to kill the spores before using again in the 37g and in the 20g.
The most horrible part of all this is that I've noticed MORE bubble algae in my beloved 67g zoo/lps tank. Not much is there yet, but I can foresee this becoming another huge problem over the long term.
I think I am going to wait until the dead rock has had a chance to cure and be used in a reef to see how effective the extreme treatment was before doing anything in the zoo tank. I'm almost sure there should be no more bubble algae in the 37g, but this stuff might be so tough that nothing will kill it
At this point, all I can do is hope, I guess.