Is this bubble algae?

[Ruth]

You should probably read the whole article that is liked above and not just parts of it. There are a few theories on how to remove bubble algea but most will tell you to try and remove the entire "bubble" but will also tell you that there is not much of a chance of spreading the problem by accidentally popping the bubble unless you happen to have the perfect storm where the spores are at the exact right time to pollinate (or whatever it is called) and spread.