outdoorsgal - hello! It's nice to meet you! Thanks for being a lifetime supporter! I have family I help with their AZ pool and their story has some similarities to yours! Neat right? They had a SWG that was ready for replacement but they have a nice pool store with liquid bleach and wanted to give it a try for a change to see how the rest of us lived.
The first thing they asked me about was the number of gallons of bleach they had to put in each day seeming like a lot. Totally understandable! I showed them the math at how their SWG was "making" that much bleach each day, so they really weren't adding any more than their SWG did already, which they never had any problems with. I explained that these TFP levels are well researched and well supported and that since the era of CYA stabilization began, we're able to maintain these FC levels to help keep our pools safe as can be. One is an engineer and the other a psychologist, so there was a discussion I'll spare you of, but rest assured, three hours later, I had two new TFP followers that were eager to give us a try!
So, let me say, I'm really proud of you for researching the chemicals you're using! MA scared the living daylights out of me the first time I read the label, but then I did research limited to its use in pool PH management only and felt a lot better (as opposed to its scarier uses in acid washing, concrete etching, and other full strength fumes and spraying and splashing horror). When used correctly for PH in pools, it really can be a super safe and awesomely cheap option! I love that it doesn't add the nasty stuff that dry acids add, right?
I was absolutely shocked when I learned that pool chlorine was bleach. I mean I was horrified. I'm swimming in bleach! What??!! LOL! Then I learned that we're really not swimming in bleach - far from it. We're swimming in a few parts per million of bleach. Hilarious! Like between 4 and 24 parts in 1,000,000 depending on your CYA level. Most tap water, that we consider super safe for drinking gallons of each day, has 0.2 PPM to 3 PPM bleach in it. We don't even drink pool water! So all things considered, I feel really great about using bleach now. I don't drink pool water, but swimming in it makes me feel really safe from all the bacteria and algae and nasty organisms that would love to take over my swimming hole if I didn't properly chlorinate it for my CYA level.
I'm sorry you're having this scare with potential black algae. My Florida pool had a massive BA infestation after years of being pool stored and my CYA being way over 200. It took a long time to fix. I urge everyone to maintain target FC per cya at all times to avoid having this ridiculous problem. In my mind, playing with the min level is not worth it. Target is easy enough to maintain. Also important to note that PH must be in range for bleach to work right, and pump must circulate enough.
Sorry for the long post, but I just want you to know, these people in your thread really know what they're talking about. Even if you find things on other websites or news articles that say different things, please ask about them before acting on them. If you really trust TFP and do everything it says, skipping none, then things like BA can't happen without really special exceptions. The levels of bleach advocated here (always per your current cya) are safe for decades on properly plumbed pools and properly finished pools. I doubt there is another site/system that is better for maximizing the life of a finish or liner or equipment. I doubt there is a system that has better research backing up it's chemistry/balance/ph/chlorination levels to balance safety for swimmers and longevity of investments. The recommended chemicals are all industry accepted and well proven.
Please know that if you TRUST the TFP system and its experts, you're putting your faith in a great place. If you try to mix it with other advice, you're making things worse, not better. You're clearly very smart, but once you get the recipe perfect, just follow it and apply your intelligence to some other problem that really needs it instead of stressing yourself out over it. Again, I applaud your safety and caution, but I'd suggest you to review the evidence TFP has amassed and based its science on instead of random things from across the net. Context and relevance matter entirely. I hope I helped. Best wishes!