CYA / Stabilizer amounts

[MossyMan]

Sorry for the lack of some details... I need to collect system info, better estimate on pool capacity, etc.

I bought a house six years ago with an inground, salt pool. The previous owners didn't maintain the property well (pool and otherwise), so I've had to keep up with some hidden problems. I've gotten to the point now where I'm ready to start doing regular maintenance of the pool (especially since pool companies around us seem to drop like flies or restrict themselves to commercial establishments).

The pool has a SWG (Pentair IC-40) and capacity of approx. 35,000 gallons. (I suspect this is off... but I have to go out and take measurements.) Hayward S224T sand filter *definitely* needs a sand swap, which I'll do soon.

Pool was opened a week ago, was kinda green. Got a bit worse, the wife dumped some combo shock/algae/something into it... I dunno the chemicals, but it's supposed to be one of those "clear it quick" things. Maybe made things look a bit better, but mostly cleaning out leaves and vacuuming was more important.

Salt was very low, so I dumped about 240lbs in, that brought it to about 2770ppm. I got another 240lbs ready to go to get it up over 3000.

With the salt in a better place, I'm working on the FC/CYA next. Both are essentially non-existent.

I went to get some CYA and asked for around 20lbs (as per recommendation from PoolMath app). They gave me a weird look... asked if I was storing for future. When I told them I had 35,000 gallons and essentially no CYA levels, they said 4lbs would suffice. Confused, I grabbed 2x4lb containers and have the first 4lbs in a skimmer sock at the moment. I'll add the second 4lbs once the first is done.

I have basically 2 questions:

1. It seems to me, based on a quick reading of some articles here, that salt is the first thing to address, then FC/CYA, then pH, etc. Is that right, or can they be addressed simultaneously?
2. Why is PoolMath recommending 20-ish lbs and they recommend 4 lbs? I've had a couple pool companies open/maintain the pool, and they always seem to get it in good shape pretty quickly. Differing or outdated opinions?

Thanks.

 

[PoolStored]

1) Stick with advice here and ignore the pool store.
2) how are you testing your water? (i.e. what kit do you have?) If you don't have a kit, I would not make any adjustments until you have one. Link-->Test Kits Compared
3) FC is always king. Use liquid chlorine if you have to. CYA is second (or first if you have 0 CYA)...or should be done together. Always do that first...then you can deal with Salt, pH etc.
4) As a new keeper of the pool, I would start with CYA of 30-40, not 70. Until you can demonstrate you can manage your FC for your CYA, don't exceed 60 for CYA.
5) Don't have any idea on the pool store recommendation. 4lb in your pool would raise CYA by 14.

I'm also skeptical of a 35K pool in Mo. What are the L, W, D in shallow and D in deepend...let's get that closer.

 

[HermanTX]

then FC/CYA,

The only thing I would add is to purchase liquid chlorine at Walmart or Home Depot. This will increase FC quickly.

For 35k gal, 1 gal of 10% LC will raise FC by nearly 3ppm - so add 2 gallons now while your stablizer is dissolving. This will get you to 5+ppm on FC.

8lbs of stabilizer will raise the CYA by 27ppm - so adding all 8lbs will get you close to 30ppm for CYA. As a minimum you want to be at 30 ppm CYA and FC at 5ppm.
If your pool is green or has algae then having 30 CYA will be good for
SLAM Process

Once you test your salt with a proper kit ref K1766 as a standalone kit, you can add more salt if needed to the level needed for your SWCG.

First address CYA and FC. Use liquid chlorine initially.

 

[MossyMan]

I'm also skeptical of a 35K pool in Mo. What are the L, W, D in shallow and D in deepend...let's get that closer.

The shape of the pool is oblong basically: not quite kidney bean, rather a figure 8. (To match the street number, I guess.)

I used a laser distance meter to measure the length and two diameters (using the oblong calculator here: Pool Volume Calculator)
I haven't measured depths yet, but I believe it goes from 3 ft shallow end to 10 ft deep end.
Measurements:
Large diam: 25.7 ft
Small diam: 21.2 ft
Length: 39.5 ft

Using that calc, it estimates 40,600 gallons.

I have four large containers of "shock".... basically 10% sodium hypochlorite... which is basically liquid chlorine / bleach? Each is 2.5 gallons, so 10 gallons available at this moment.

I updated PoolMath to use the 40k gallons figure from the calc, and it suggests adding 245 oz. adding 150oz. (EDIT: I had the wrong percent in the app.)
If 2.5 gallon jug is 320 oz, I need about 3/4 jug. 1/2 jug.

Seems legit?

2) how are you testing your water? (i.e. what kit do you have?)

I have some AquaChek strips and a Pentair Pro-11. Both might be a bit old (5yrs?), but what I have at the moment. (I intend to order a better kit.)
Both kits are telling me that I essentially have no FC/CYA.
I also have a digital probe that will measure salt and pH. Using that, for the moment, to measure salt and cross-check the pH measurement of other kits

 

[MossyMan]

The pool... that's a slide, not a tail.

 

[MossyMan]

Quick sloppy measure of depths agrees with my 3ft and 10ft guesses.

 

[PoolStored]

What is the radius of each circle, and which is the 3 foot end?

 

[MossyMan]

What is the radius of each circle, and which is the 3 foot end?

Large radius (shallow 3ft end): 12.85 ft
Small radius (deep 10ft end): 10.6 ft

 

[generessler]

If I'm reading correctly, you should not need anywhere near 240 more pounds of salt to reach 3000. More like 80 if the volume really is 35k. Less if smaller. Overshooting is bad because the only way to reduce is drain and refill.

 

[MossyMan]

If I'm reading correctly, you should not need anywhere near 240 more pounds of salt to reach 3000. Closer to half that if the volume really is 35k. Less if smaller. Overshooting is bad because the only way to reduce is drain and refill.

If I set the goal in PoolMath to a target of 3000 for salt, then it recommends 80 more lbs.
I had the goal at 3600 for salt, b/c that's what the Pentair IC-40 docs recommended. Maybe that's overkill?

 

[PoolStored]

I think that your pool is close to 34,000 lbs based on my calcs.
How are you testing your water. We recommend that you have your own kit. Recommended kits. Link-->Test Kits Compared

I would not make additions based on pool store testing.

 

[MossyMan]

I think that your pool is close to 34,000 lbs based on my calcs.
How are you testing your water. We recommend that you have your own kit. Recommended kits. Link-->Test Kits Compared

I would not make additions based on pool store testing.

I mentioned the kits I have above... probably not optimal so I intend to get a better kit. Have not done any pool store testing.

 

[generessler]

If I set the goal in PoolMath to a target of 3000 for salt, then it recommends 80 more lbs.
I had the goal at 3600 for salt, b/c that's what the Pentair IC-40 docs recommended. Maybe that's overkill?

By all means do what the manufacturer wants. My cell wants 3000. I thought that's what you were shooting for. Still, go easy to avoid overshooting.

 

[PoolStored]

I mentioned the kits I have above... probably not optimal so I intend to get a better kit. Have not done any pool store testing.

They are not, and if they are 5 years old the reagents are likely bad and reporting incorrectly. You will save yourself a lot of time and money with a good kit. I'd get a proper kit, including salt test before you make additions other than adding some chlorine. If you overshoot salt, you will be replacing water.