Pool Surface
The plaster surface is noticeably old, likely over 35 years and somewhere between 27 and 35 years old. I see wear on the steps and other locations common with this age surface.
I would estimate the surface likely has less than 1 to 2/3 years of remaining life, or less most likely. You will know when resurfacing is required — which I feel is now — when water loss status becomes apparent.
For a pool this size (easily 25,000 to 30,000 gallons), replastering would likely run between $10,000 and $14,000 depending on options. It may be more than that.
Cost summary (this section only)
• Full replaster: $10,000–$14,000 (possibly more)

Waterline Tile, Skimmer & Concrete Decking
The waterline tile is all original and likely 30 years or more old. There is noticeable calcium buildup on the top half of the tile and cracking in one or two areas. Due to the age, heavy cleaning may not be the best approach unless re-mortaring is also planned. It may be more beneficial and cost-effective to replace the tile completely. New tiling on a pool this size might cost $1,500 to $2,500 and would likely be recommended (and potentially required) at the next replastering stage.
The skimmer throat is older and due for re-mortar. It runs higher water levels more consistently, which wears the throat out the most and quickest, along with high flow since it is the only skimmer. The skimmer throat will need service in the next 1–3 years. Just the skimmer throat alone would be around $500 extra on top of re-tiling. It will likely require the skimmer to be replaced and updated due to its age as well. This would be a very smart thing to do.
The concrete decking has settled in some locations. It is a little higher on the north side, a little lower on the northwest side, a little higher around the diving board, and pretty much perfect between the house and the pool until a raised section in the middle-south and again some raised sections on the east side. This settling is natural due to soil and moisture conditions. The low-cost solution is to grind down the raised edges and fill with mastic. Because of the amount of linear footage, the cost would likely range between $1,000 and $3,000. $3,000 is the most accurate number to get it all done correctly.
In conclusion, none of these items are required immediately, but will likely be required in the next 1 to 3 years or less as these issues will progress. You will know when re tiling / skimmer throat needs to be done when we start seeing water loss occur more heavily. The water results do not reflect major water loss status at this time, but recommend re testing in 1-30 days to confirm.
Cost summary (this section only)
• New waterline tiling: $1,500–$2,500
• Skimmer throat re-mortar: ~$500 extra
• Full skimmer replacement (recommended): additional (not estimated)
• Concrete decking grinding and mastic fill: $1,000–$3,000 (likely closer to $3,000)

Water Quality
Water quality indicates organic matter is likely growing inside the pool due to the higher levels of pH and alkalinity. This could also be due to the mass amounts of organic matter that enter the pool with little to no bottom cleaning currently present, as it is missing. The leaves will just deteriorate over time into the water, increasing the pH and alkalinity.
Corrective action is needed: adjust pH and alkalinity (less than $20), phosphate treatments to help remove the decomposing organic material ($100–$200), and potentially balance cyanuric acid slightly higher if required (less than $50).
There is not a huge mass amount of algae present. That is likely because the chlorine is so high — free chlorine and total chlorine are over 10, likely around 20 — and that is muting the algae that is present. If that is the case, additional algae treatments of around $100 will likely be recommended and required to bring this pool to a more ideal standard.
Cost summary (this section only)
• pH and alkalinity adjustment: <$20
• Phosphate treatments: $100–$200
• Cyanuric acid adjustment (if needed): <$50
• Additional algae treatments: ~$100

Main Drain and Skimmer
Main Drain
The main drain in the pool is a single drain with no VGBA compliance. It should be updated to an STX retro cover for safety, but that would still not be VGBA compliant. Instead, when plastering occurs, update the main drain to a channel drain. Someone will charge $500 to $1,000 to put a channel drain into this setup.
You would be wise to consider adding a dual channel drain setup and increasing the pipe size to 2½ or 3 inches, or a dual 2-inch that tees into a 2½-inch line. This would greatly benefit a large pool like this and could only be done at the replastering stage. That might cost up to $3,000 extra to do in the most ideal way versus the low-cost, least ideal way.
Skimmer
The skimmer is a very old screw-style skimmer. I’m very surprised that this is not leaking, even though it very well may be leaking due to its age and the putty present around previous leak repairs.
It would be extremely important to update the skimmer at the time of replastering, as mentioned in the tile section. In the meantime, it might be wise to consider updating the float, float O-ring, weighted basket, new skimmer lid, and new weir door. All of that installed would cost less than $500 to bring the skimmer to at least a better functional position, as it is the main source of leaf-removing capability in this pool ongoing.
The full skimmer replacement at replaster would add $500 up to $3,500 depending on options.
Cost summary (this section only)
• SDX retro cover (now): $200+
• Channel drain upgrade at replaster: $500–$1,000
• Dual channel drain + larger pipe upgrade at replaster: up to $3,000 extra
• Skimmer component updates (float, O-ring, weighted basket, lid, weir door): <$500
• Full skimmer replacement at replaster: $500–$3,500 additional

Bottom Cleaner
There is no bottom cleaner present, even though we do have a booster pump that will power a Polaris 280 or 380 ($650+) or a more preferred Quattro ($1,200+). Those appear to be options present.
Cost summary (this section only)
• Polaris 280 or 380: $650+
• Polaris Quattro: $1,200+

Manual Fill
The manual fill is located next to the home under the red box. When you turn it on, it does operate the plumbing line connected to the pool. It has an ever so slight leak at its fill valve head bolt that can easily be adjusted for less than $20 in labor to get it to be leak free most likely.
Otherwise this is all original and is in working condition at this time.
Cost summary (this section only)
• Adjust fill valve head bolt to stop leak: <$20

Pool Light
The pool light appears to be original, likely a 10 or even 12 inch niche and light. It does turn on and operate, which is less than ideal because the can is clearly filled with condensation and water, which is a danger. This is likely because it does not have any GFCI protection on it or even any GFI for that matter and should be updated ASAP for safety (which will be discussed in the board and timer section).
In the meantime, the cost on a new light can is between $300 up to $1,200 depending on options from low cost LED up to high-quality LED color. Note that you do have an opportunity now to switch over to 12 V for only an additional $300-$500 in labor and parts to install a low-voltage transformer and achieve low-voltage electricity in the pool only and not any high voltage, making it death proof.
Cost summary (this section only)
• New light can: $300–$1,200 (depending on options)
• 12V low-voltage conversion (transformer + labor): $300–$500 additional

Filter
The filter is a Waterway model, which is notorious for being a lower-cost B- option. It uses comparable parts to Pentair with the same virtual size tank and model. However, it uses lesser quality plastics, and it is clear that the fiberglass is already starting to come off this filter. While it isn’t an issue at this exact moment, it will be in the next 5 to 10 years (likely closer to five), where leaks will begin to develop and water loss will occur — potentially even less than that (1 to 5 years) just judging by its quality and condition due to sun exposure.
A new filter is between $800 to $1,200 depending on size, and you’re gonna pay someone around $800 to install it for parts and labor overall.
It only needs to be serviced currently but may have issues with elements ($300+) or a hole inside recommend service. In fact, it may have been serviced recently in the past month, and it will need regular quarterly service here in the next 1 to 2 months, which may range around $100 to perform. This will include simply cleaning the filter elements and servicing the tank covering and cleaning out the filter basin.
Cost summary (this section only)
• Quarterly filter service (cleaning elements + tank): ~$100
• New filter + installation: $1,600–$2,000 (depending on size)

Filter Pump
The filter pump is a 2.7 VS Plus HP Jandy pump. It is in relatively good condition.
It is slightly oversized for the plumbing application present, but it also appears to be missing its bonding connection, which could easily be done in less than two minutes. We’ll just call it $20 in service to accomplish.
The pump basket is completely filled with water, which is great — no issues there.
Ideally get this out of the sun soon to help prolong its life, which could potentially be 10 to 20 more years if it hasn’t been damaged too greatly from the sun. It does appear to have a fair amount of sun exposure — at least five years, maybe closer to seven.
Cost summary (this section only)
• Bonding connection service: ~$20
• No other immediate costs required

Booster Pump
The booster pump did turn on via the controller option four. It did turn off but then turned right back on — slightly unusual, but likely more to programming than anything.
The booster is not brand new. It’s at least five years old. It is working, but this particular model likes to spring a leak on its front end wet end, and it does not appear to have done that yet. But it will in the next 1 to 5 years, likely closer to one. When that happens, it will lose a lot of water and majorly affect the pool.
So it might be beneficial to consider just updating it now. These pumps are as cheap as $400 up to $800 for a high-quality HydroBoost Pentair booster pump, or ideally just the wet end can be purchased online for $100–$200 plus installation might be around $400 for either option.
Also consider changing the soft hoses to hard plumbing instead. It’s more long-lasting, and this current hose setup will also spring a leak soon and cause you to lose water in the pool. Hard plumbing would be around $400 to $600 installed or less.
Cost summary (this section only)
• New booster pump: $400–$800
• Wet end only: $100–$200 + ~$400 install
• Hard plumbing upgrade: $400–$600 installed or less

Board and Timer
The board and timer are all original and older. The left timer was for the booster pump. It has been disabled and instead it is all wired through the Jandy variable speed pump and controller.
Still, there is no GFI or GFCI protection on any of this. It would be wise to likely install a junction box. An electrician would likely run around $300–$350 for a junction box, the variable speed GFCI breakers for around $200, and labor might be another $300 on top of that.
The pool light junction box and switch tower area may need attention. Difficult to tell at this time but potentially $300 in parts and labor I would assume as well.
It should all be done right away for safety.
Cost summary (this section only)
• Junction box + variable speed GFCI breakers + labor: ~$800–$850
• Pool light junction box and switch tower area attention: ~$300 (parts and labor)

Plumbing
The plumbing was last updated during the variable speed pump and filter installation. It is all 1.5-inch, which in general is less than ideal for a pool this size. More preferred would be at least 2-inch, if not 2.5-inch minimum. So we are already half the plumbing size we wish we could have here.
At least we have approximately a 1-inch return supply side for the bottom cleaner, which is great. Overall the plumbing here is blue glue and leak-free.
In a more ideal world, you would actually replace all of this plumbing, condense the equipment pad down at least half its current size, update the plumbing, and maybe potentially install a new check valve or the like. This could be done for less than $1,000 in parts and labor and would probably include the booster pump re-plumbing as well. In fact I would just classify it as $1,250 or less and that should likely be done in the next 10 years or less.
If it is kept out of the sun using UV mesh for $50, painted and re-labeled for another $200, it likely could last 30 years or more.
Cost summary (this section only)
• Full plumbing update and equipment pad condensation: $1,000–$1,250
• UV mesh: $50
• Paint and re-label: $200