Quote Originally Posted by paulvzo View Post
1. Ben, you mentioned Chlorox Ultra as having "goop." I think you will find that said goop is sodium hydroxide. Lye. Incorporation of sodium hydroxide helps turn the water in laundry alkaline and then, hence, tends to help the detergents. Similar to "Washing Soda" or borax.
NaOH is the 'extra' in PLAIN bleach, including PLAIN (6%) "Ultra". But "Ultra" comes in 'flavors', including gelled, with detergents, etc. We've had problems with users not distinguishing between plain "Ultra" and 'flavored' "Ultra" -- it's easier for us and for them to say PLAIN 'store brand' 6%

2. If one wants to increase pH, why not use lye/sodium hydroxide? While having little or no buffering value, it is free of downstream problems like anything with carbonates. In fact, sodium hypochlorite is made by running chlorine gas through sodium hydroxide solution. That's why liquid chlorine raises pH. Once upon a time Red Devil brand drain cleaner was straight sodium hydroxide. The old solid Drano was the same, and a few aluminum flakes to make many bubbles. Said products are almost impossible to fine now, sadly. But there are also hobbyist (photochemical) merchants. Major pH bang for the buck.
It's hard to find, and is dangerous, compared to most other chemicals. Mostly it's available as drain cleaner, often with additives. When we recommend chemicals, we have to make judgements about whether the average user here can follow the instructions well enough to do what we say safely. NaOH falls outside that area. (There are all SORTS of things I do locally, that I never mention here!)

3. Why can't we buy granular sodium hypochlorite? Fifty years ago my father did, we had a drum in the garage. A cup or whatever as needed, no jugs, no hassle. EPA or shipping regs? Sure as heck beats water, jugs, etc.
You're confusing sodium hypochlorite with calcium hypochlorite. Sodium hypochlorite, above 20% or so, starts becoming too unstable to handle or transport.

4. This is the only site I've seen that points out the relationship between levels of cyanuric acid and measured free chlorine needed. Should be well known, obviously not. A "DOH!" moment for me. Thank you. On that topic, after draining and refilling - oh, I do love that well Dad put in - I found that chlorine disappeared at alarming rates, just as you say. From 3ppm or more to nothing in a few hours. Yes, the pool is in full Florida sunlight. A mere 3 pounds of stabilizer changed that.
There are other sites, now. (But they copied me! )

5. Does anyone use a pH meter? This is something from my photochemistry days after decades of using color change strips. I think it cost about $20 on eBay. Although you do have to keep a pH 7.0 test solution and check against it, it's so easy to get pH almost instantly accurate to the one tenth.
I'm glad you got an accurate pH meter for $20, but that's the exception, not the rule. Most people skip the buffer checks, and end up with massively inaccurate pH results. We only recommend meters for the color blind.