Cusser

No. Water boils at 212F, ALL the water would've had to be evaporated for that to happen, and typically there's a flow witch to interrupt voltage to the heater.

You could temporarily try a rubber stopper in that hole, and then see what happens. Ace Hardware sells individual stoppers of various sizes, in the small drawers, inexpensive.

My pool ladder is 21 years old, in the Arizona desert. The steps swing up for child protection if one needs that.

Soaking in vinegar or vinegar-soaked rag can remove water deposits. I wouldn't use any "sealer" on the threads, the seal is made by the gasket. A little RTV or Permatex Aviation on the gasket surfaces might help.

I would say to stay current, just limit your time. Mrs. Cusser is an addict for online so-called "reality" shows, spends way too much time remembering (and unfortunately trying to tell me about) those people's lives. Why should I care who marries life-imprisoned convicts or that Teen Moms now make their living from the show and live in nicer homes than I do?????

I believe that Canadian Spa Tech means that a pressure switch or flow switch will NOT activate, so no power will be delivered to the heating element.

Got my cover holder like 20 years ago; it's two metal bars, bent like in photo.

Elbow grease and a green scrub pad. No soap or detergent, will then foam almost forever !!!

If the housing is not cracked, I would think a new O-ring or new gasket might fix the leak. If a gasket, and not available, I might try a thin film of RTV on each side of the existing gasket, or cut a new gasket from rubberized sheet gasket from the auto parts store.

Is it leaking from the hose/hose clamp, or from the body of the assembly?

Given my experience with a similar-size spa, I'd say 5 minutes with jets on should provide plenty of mixing. I don't use test strips myself.

Not on my 1988 CalSpa, just need to get the water level over the drain. If I need to, I can plug the skimmer hole with a big rubber stopper.

Yes. My old spa is about 350 gallons, and no big deal to drain and refill; if I'm there during this, I use the under-$100 immersible pump I use for my above-ground pool. Biggest "work" for me is manually bailing out the last two inches of water, and then cleaning (rubbing) the sides/surface by hand. When filling, I usually add fresh water some, then drain again, maybe even repeat, to get as much of the "old" water out of the plumbing.

When one drains a hot tub, cannot get ALL the water out, some residual stays in the plumbing. As a chemist in the soap and detergent industry, it takes very little surfactant (surface active agent such as soap from fats from bathers' skin or detergent) to make foam like that. I'd try a little silicone anti-foam.

I've had my CalSpa since 1988, and have used sodium carbonate to raise its pH, and have never used any borates of any kind. I've also used sodium borate for similar in my above-ground pool. On a few occasions I've used powerful 100% sodium hydroxide powder to raise pH in the CalSpa and in my 15' above-ground pool, but this is significantly more dangerous to add (wear gloves, goggles). https://www.acehardware.com/departments/plumbing/drain-openers/drain-cleaners/4239216

If I was in that situation, and knew what I was doing, I would likely try that myself, and just be very careful. On those older 3-terminal 240VAC connections, there needs to be a 4th/separate grounding wire. I can't remember offhand which of the two terminals are "hot" legs and which is the neutral, see Google.

Is that mold????

I will comment, as a retired industrial chemist; I just looked up "Spa Up" online, it's simply 100% baking soda, like less-expensive Arm & Hammer from Walmart. That stated, sodium bicarbonate is essentially a buffer to help maintain pH around pH 7. To raise your pH you need to add sodium carbonate powder, which is about pH 10. So get some sodium carbonate 100%. Looks like Home Depot sells sodium carbonate 100% https://www.homedepot.com/p/Pool-Time-pH-Up-6-lbs-Balancer-23606PTM/310588667 Note that "Leisure Time Alkalinity Increaser" lists its ingredient as "100% sodium hydrogen carbonate" so is the SAME as sodium bicarbonate and their "Spa Up", very deceptive !!!

I have a 1988 CalSpa and it has two of the "serviceable type" gate valves; of course those also stopped sealing back in the 1990s. I did buy replacement gate valves at Ace Hardware on the corner (before I had Internet to find stuff) after one simply broke/stuck in the closed position, so the spa was unusable. I transferred the guts from the new to the existing ones, the holes lined up perfectly. Anyway, I never touch those gate valves nowadays. I routed the plumbing out of the cabinet to overcome the sucky CalSpa design, and use two new rotating valves on each side of the out-of-cabinet filter.

Even fats from bathers' skin will saponify and become soap. And CanadianSpaTech is correct about residual detergent from swimwear. I worked decades for a soap and detergent company.

I wouldn't even try Flex Tape for this. I did buy some Flex Tape once, because it claimed it could be applied underwater; I tried it in my own above-ground pool liner. I returned it for refund....

Home Depot often has a list of contractors who do all types of their installations; ask them, and pay through Home Depot. I got a set of French Doors purchased and installed doing this.

Yep, that will be fine. Also, maybe order online, like from Doheny pool supplies. I bought my own 35 lb. container (for my above ground pool) in the spring when it was available locally (Home Depot).

I've had my CalSpa since 1988, and I only add sodium bromide with a new water change. I use 1" bromine tablets in a floater, and shock with a little monopersulfate every 2 weeks or so - if I remember. I adjust pH when necessary, don't use other chemicals.

I also agree that the area is a red flag !!! Power disconnected, soaking a rag in vinegar and letting it sit overnight should dissolve the corrosion. The copper strips themselves can be cleaned with steel wool.