Ok, first off any phosphate is a bad phosphate. Try lowering it to where it can't be read. Use either distilled water or water treated through Reverse Osmosis if you are not. Secondly you probably aren't reading any nitrates because the Caulerpa, or the seaweed that looks like a grapevine, does a great job at filtering ammonia nitrite and nitrate from your water. Some people use that instead of cheato. Anyway, easy way to take care of it is yanking it out. Leave none of it behind.
Aptasia is not an algae, rather it is a nuissance anemone that can quickly multiply. Cut them off with a razorblade making sure to not leave any part behind as that one part can grow into one or multiple aptasia. They can sting livestock and will compete for food so they should be eradicated.
Lastly....bubble algae....ugh....I hate bubble algae. The problem with bubble algae is that it can survive with hardly any nutrients. I do 38% water changes weekly and have low bioload and feed once every two to three days and I still have some. Use a razor blade at the base of the bubble, making sure not to pop it, to take it out. I will tell you, it's easier said than done. I almost got rid of mine and I accidentally popped two. A week later and more were popping up. It's a battle. Good luck.
