Cusser

That's baking soda, identical to Arm & Hammer baking soda at Walmart, etc. Your white precipitate is likely insoluble calcium carbonate, like a hard water deposit. That will not readily dissolve....

What is the chemical composition of this “Alkinlinity Increaser”? The container should say, or look it up online, like manufacturer's SDS documents. Likely is sodium bicarbonate or sodium carbonate....

Oh, crap !!! I've only been hosing off my filter, for 34 years now !!!

I'd let it sit in the sun a few days (or a couple of hours here in Arizona) to dry out. If mine, I'd remove those screws and look inside, and let moisture escape from there too. The hair dryer thing might help too, but might take a while, don't let anything burn or melt. If you can return stuff at no cost to Amazon like with Amazon Prime, might not hurt to order a replacement just in case. I have an above-ground pool, and if we get a severe rain, my pump motor might need a couple days to sit and dry out before it works/stops actuating its GFCI.

Interesting. Because in 1988 we had an 84" spa installed on our existing concrete patio covered by a solid roof, and we/the spa dealer NEVER even measured to see if there was a slope to that slab. I'm under the impression that the slab being flat is way more important to it being level. Anyway, just last year (1988 spa still is in use) I was curious and took some photos, found it a little off-level.

After this occurred, did you test the receptacle for power with an AC voltmeter or even a lamp? I would think that a tub would need to be on a dedicated circuit, and likely a ground fault circuit, so check to make sure a breaker or GFCI hasn't tripped. In most homes, stuff like refrigerator and washing machine get their own 20-amp circuits, where stuff like lights, TV, stereo uses shared circuits. In my home, after I added an over-the-range microwave in place of a simple vent fan, use of the countertop microwave at the same time tripped a breaker, so I had to tap into another circuit for that.

Desa - that was a great idea !!!

I'm not letting my 1988 CalSpa read this !!!

If your location is Phoenix. might be worthwhile to check out http://www.arizonaspacovers.com/

Someday on mine I'll try marine epoxy.

Great. I'd get a strap wrench, a curved-jaw oil filter wrench, or a curved Vise-Grip type wrench for future "expeditions".

I've had my CalSpa since 1988. In the old days, we didn't heat it in summer, used it as our "swimming pool", the kids loved it. In fact, being in Arizona, we left the cover off overnight one night a week to allow the water to cool, the ambient temperature heated the water so much. Maybe 15 years ago, the electric company changed away from the "time of day/demand" rate where one would be surcharged for the highest single hour demand in that month; so I started leaving the spa at 104F full time on the temperature setting control, and was surprised how few minutes per day the heat/pump actually came on. Now in summer I keep same temperature and just have filter run 2 hours a day. Since I use a leak seal product to seal an inaccessible leak, I don't like to let temperatures vary too much.

I have a 1988 CalSpa that has a slow leak (less than 1/4 inch a day) for over a decade which I have not been able to locate; it's not leaking in the "equipment" section, and I've torn apart the other two sides that are accessible even tearing out sprayed-in foam looking for evidence of leakage (the 4th side is like 6 inches from the home's block wall). When it leaks, I can see water on the patio slab. So I've used a leak seal product successfully on mine. How often? Maybe I average once per year adding leak sealer. I change out the spa water maybe 3 times a year. Being as how I have one of the world's oldest operating spa, it does have some cracks in it which I don't know if go through. I've never done the "test" to see if the leak stops once the level drops to a certain level.

I could view the videos. But too me, the blurriness and lack of description/words make them useless.

Can you temporarily remove the filter cartridge, put the housing back on, and try?

I have an old VW Convertible with a vinyl top. The UV from direct sun is a killer for vinyl, way worse than the heat here in Arizona. Personally, I use no protectant on the convertible top or my spa cover.

I'm in Arizona, and my spa is on my covered patio so gets more sun in the "winter" when the sun is low. However in 33 years with this spa, I would say that I only replaced the cover 3 times. I never cover the cover, or apply any coating or cleaner to it. Yes, if water gets into the foam itself, the cover is way heavier and does not insulate as well.

I can't see much either, pictures are too small. Sounds like you must use a flat gasket there. Maybe source out a slightly-thicker gasket; I don't know if Permatex Aviation (brown goo) will help there. Question: how are you tightening that big white nut - just by hand? Because you might need more torque to tighten it a tad more. I might suggest a rubber strap wrench, or what comes in handy for me is ViceGrips 12LC.

Hey, my cell phone went out of service in February, had to upgrade to a 4G phone. I bought a brand new TracFone Flip Phone for $20, so now I can take pictures for the first time (once I learn how). So I have a dumb phone, not a smart phone. Old and new.

OK, I must ask (my own spa is a 1988 vintage CalSpa). So just what does a remote control for a spa do????

Could be PVC, which typically glues well. Can you measure the exact inner diameter of the broken piece, maybe a length of PVC could be glued in, or that inner surface tapped for a hose barb fitting.

Chlorine liquid (sodium hypochlorite) is not that stable over time. Pool liquid chlorine is typically about 10% active, bleach for laundry is about 5% active. I have a 22-year-old above-ground pool and 33-year-old backyard spa. These have vinyl liner and acrylic/fiberglass and therefore pH drops over time (opposite of a plaster pool). Instead of pool/Home Depot sodium bicarbonate I use Arm & Hammer baking soda, same and cheaper. I use pH Up (sodium carbonate) from Home Depot. I buy 1" bromine tablets locally (so far) and 3" chlorine tablets locally too, shop by price. I have purchased monopersulfate shock online for the spa (cheaper) and powdered chlorine shock online too. For the times I have needed stronger caustic to raise pH in the pool, I have used 100% sodium hydroxide crystals from Ace Hardware, sold as root killer https://www.acehardware.com/departments/plumbing/drain-openers/drain-cleaners/4239216 As an algae preventative for the pool, I have purchased Zep Root Kill (copper sulfate crystals) from Home Depot.

Ferrous ion (Fe+2) will not simply filter out; your sanitizing agent (bromine or chlorine) and oxygen in the air oxidizes the ferrous ion to ferric ion (Fe+3), and ferric oxide is what we call rust. If mine - I might try a pool/spa chelating agent for metals. These can contain a form of EDTA or etidronic acid. How these would affect calcium levels is something I'm not familiar with, as these also chelate calcium. You might want to investigate those, are old commercially. https://www.google.com/search?q=chelating+pool+chemical&sa=X&biw=1354&bih=627&tbm=shop&ei=f4kbYsHAEqnIkPIPvcqRwAg&ved=0ahUKEwiB_Kr2iqD2AhUpJEQIHT1lBIgQ4dUDCAU&uact=5&oq=chelating+pool+chemical&gs_lcp=Cgtwcm9kdWN0cy1jYxADMgYIABAeEBg6BggAEAcQHjoICAAQCBAHEB46CggAELEDEIMBEEM6BQgAEIAEOgoIABAIEA0QHhAYSgQIQRgBULIFWLcqYNs3aAJwAHgAgAHAAogB_xGSAQcxLjcuMi4ymAEAoAEBwAEB&sclient=products-cc#spd=5097597827927057343 I'm afraid that a low volume reverse osmosis system to use for spa water only will be a few hundred dollars, need cartridges changes like once a year, and still need calcium level to be adjusted.

Sandpaper cloth "tape". Washcloth soaked in vinegar. Naval jelly. There are ways to clean most, do not use with rust on the seal area.

I have a 33 year old spa. I had a leaky pump seal once, and bought a repair kit and fixed it myself, maybe 20 years ago. Wasn't rocket science. Be sure to clean up the motor shaft where it goes through the new seal, must be smooth and round.