New House, First Time Pool Owner, Trying to get it up and running

[Blade_Beam]

Hello, I got myself in the deep end, literally. We just purchased a new home with a pool. I've never owned one before and found TFP before we finalized the sale. The previous owners opened the pool for the year, but it looks like they didn't maintain it since then. I've been trying to get it back into proper balance for use, but turning out to be difficult. It is an IG vinyl lined pool, ~35545 gal (18' x 44' rectangle), 1 hp Whisperflo Single Speed Pump, 48 sq ft Pentair FNS Plus DE Filter with a CoverStar autocover. The water was clear and when I first tested with my Taylor K-2006c (I didn't run a full test) on 6/22, my results were:

FC: 0.0
pH: 7.4
TA: 240
CYA: 100
Temp: 80F

I added 2 lbs of hth Super Shock as that's what I had from the previous owners on 6/24. On 6/25:

FC: 1.0
CC: 0.0
pH: 7.4
TA: 220
CH: 500
CYA: 45
CSI: 0.42
Temp: 78F

I've vacuumed almost every day with my Dolphin Oasis z5i. I brushed the walls on 6/26 as there was algae on the walls, I added 5 lbs of Utikem One Shot Shock (50% Cal-Hypo) that evening and the pool started appearing a little green, especially the morning of 6/27 and much cloudier. I tested the morning of 6/27:

FC: 1.8
CC: 0.0
pH: 7.2
CSI: 0.21

Thinking I simply needed to get the the appropriate FC level, I added 242 oz of 8.25% Bleach as per the PoolMath app. I vacuumed and backwashed the filter thinking that it needed done as the pressure was 24, after backwash, I'm still at 24. Recheck of the FC later that evening was 1.0. Thinking I needed to SLAM, I added the bleach I had on hand, 726 oz of 8.25%. When I checked 3 hours later before bed:

FC: 9.2
CC: 0.4

I put the cover on it to try to limit FC loss overnight, especially since it wasn't terribly high. I ran a full test this AM:

FC: 5.6
CC: 0.6
pH: 7.4
TA: 180
CH: 460
CYA: 90
Temp: 82F
CSI: 0.28

The color is much better, but it's still cloudy and I'm having a lot of FC losses, even with the cover on. I guess the question is: Am I precipitating out calcium with the high CH and that's what's causing the cloudiness and FC loss or am I still working algae or some combination of the two? Do I just need to do an appropriate SLAM and it should even out? We're buying a lot more bleach today to try to get there.

I do have a new filter grid that I am going to install with my new PureLine Prime Variable 2.7 max HP pump as soon as it arrives from InyoPools to try to improve my energy efficiency.

Thanks for the help! My PoolMath logs are in my sig, but the times are not crossing over appropriately from my Samsung S8+.

 

[mknauss]

Welcome to the forum!

Your Poolmath logs (thank you!) show your CYA bouncing up and down. Are you draining and refilling the pool and then adding CYA back to it? CYA just does not change, you must physically either remove the water with it from the pool or add it to the pool to change its levels.

You need to nail down what the CYA level is. Then follow the SLAM Process
When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

 

[Silver_2000]

And stop with the store bought shock since they likely add MORE CYA

Just get bleach with no additives.
Once you have things under control and know your CYA you can CAREFULLY use up the old chemicals. BUT if your CYA is already 100 you dont want it higher
That plus the test only goes to 100. you may be higher

 

[Blade_Beam]

I finally got home from work requirement and was able to retest chlorine and CYA. Tested from 2 different sites in the pool per mknauss' method and got 100 each time, so it looks like I'm at 100. FC was 3.6. I was able to get 12.5% liquid chlorine from Menard's for $2/gallon, so I picked up 16. Per the PoolMath app, I need to add 10 gallons to reach a target SLAM FC of 39.

Missing anything? Attached or photos I took when I got home as I was testing. It looks to be clearing up and I need to vacuum again as I'm seeing sediment in the bottom of the deep end again (Precipitated calcium?) Thanks for the help!

 

[Mr Bruce]

It would be much better to replace water than try to maintain a CYA of 100. Plus, it might be more than 100.

Do you have a submersible pump?

 

[Blade_Beam]

It would be much better to replace water than try to maintain a CYA of 100. Plus, it might be more than 100.

Do you have a submersible pump?

About how much would I have to replace?

 

[mknauss]

With a vinyl pool you can drain to the point of leaving 1 foot of water in your shallow end and then refill.

 

[Mr Bruce]

I would say a minimum would be 40%. 50% would be better. Depends on if you are really over 100 or not. Mix your pool water with tap water 50/50 and test again.

 

[crusemm]

This Dilution Calculator will help you figure it out

• C1 is the current concentration of CYA
• V1 is the volume to be removed (i.e. how much to remove from the pool)this is what you are solving for
• C2 is the final concentration of the diluted solution. This is your goal CYA (50)
• V2 is the final volume of the diluted solution. This is the volume of your pool

I know the volume units are Liters not gallons, but it doesn't really matter.

After you drain/fill, retest and drain fill again as required

 

[Silver_2000]

if the test says 100 it could be 200 or 150 or 110

If your CYA is 100 ( and not 200 ) and you want 50 you should plan to remove 60-70% of the water... That way you dont waste the effort and the refill water and end up with still HIGH CYA

 

[Blade_Beam]

OK. Replaced ~50% of the water. Redid my pool volume math as I discovered I had been informed wrong on the depth of the deep end. Replaced the filter grid today and I'm glad I did, the old one was at the end of its rope. New Pureline Prime Ultimate VS pump was supposed to come today, but is delayed until Monday, so can't get the filter set or start a SLAM until then. Did recheck my values:

FC: 8.8
CC: 0.2
pH: 7.6
TA: 280
CH: 350
CYA: 50
CSI: 0.53

I do have 2 submersible pumps recirculating the pool, so I figured I could work on the pH. Yes, I know, sulfuric acid is bad, but it's all I had on hand as they had left a full gallon (bad new pool owner). So I followed the directions and added 1 quart. I'll recheck in the morning and impatiently wait for my new pump so I can SLAM and get this pool where it should be.

 

[Blade_Beam]

Thanks for all the help everyone. Was able to get the pool balanced out and swapped out the pump, which really got the pool cleared up with the new filter grid. Also installed a Pureline 60k gal HD SWG which has really eased maintenance.