Feedback on current water balance

[rack04]

New pool owner since July 2023. When I took ownership the CYA (180) and CH (800) were both very high. I assume the previous owner used chlorine pucks and cal hypo to disinfect since the FC was likely maintained at 3, not considering the FC/CYA ratio. I switched to liquid chlorine and have followed the advice on this forum religiously over the summer. Here are my current test results:

PH 7.8
TA 80
CH 360
CYA 60 (Still doing partial water changes to target 40)
FC 8.4
CC 0
Temp 70.7
CSI 0.08

How seriously should I track and adjust the CH? According to PoolMath with my plaster IG pool I should target 250-650. I have a pool heater that I plan to use occasionally over the winter. I have a large pack of cal hypo shock I could use to raise the CH if necessary. Thanks in advance.

 

[mknauss]

The water chemistry data looks fine. If you get a lot of rain and over flow you can use some of the cal hypo to raise the CH back but I would not use it now. The CYA will naturally fall over time so no need for water changes.

Relax, you are in a groove. So very little change is needed. As we approach winter, you can reduce testing and let things ride a bit more.

The next step to make your like easier will be to add a VS pump and SWCG.

 

[HermanTX]

New pool owner since July 2023. When I took ownership the CYA (180) and CH (800) were both very high. I assume the previous owner used chlorine pucks and cal hypo to disinfect since the FC was likely maintained at 3, not considering the FC/CYA ratio. I switched to liquid chlorine and have followed the advice on this forum religiously over the summer. Here are my current test results:

PH 7.8
TA 80
CH 360
CYA 60 (Still doing partial water changes to target 40)
FC 8.4
CC 0
Temp 70.7
CSI 0.08

How seriously should I track and adjust the CH? According to PoolMath with my plaster IG pool I should target 250-650. I have a pool heater that I plan to use occasionally over the winter. I have a large pack of cal hypo shock I could use to raise the CH if necessary. Thanks in advance.

The only additional point I would add is as water temperature decreases your CSI will go lower (negative) but that is fine. I tend to keep my pH around 7.8 as water temperature decreases to avoid going below negative 0.3 on CSI

It would be good to test your tap water (fill water to your pool) for TA and CH to determine how that affects your pool chemistry.
I run my CH at 350 for most of year so that is fine. Having a CYA of 60 with LC is great.

 

[Mdragger88]

 

[pjt]

FC 8.4

Use the 10 ml sample so each drop is 0.5 FC. Saves time and reagents.

Post your fill water TA and CH when able.

 

[rack04]

Use the 10 ml sample so each drop is 0.5 FC. Saves time and reagents.

Post your fill water TA and CH when able.

Thanks. I go back and forth between 25ml and 10ml for CH and FC. When I want higher accuracy I go 25ml. Why? Because I'm an engineer and nothing else.

 

[newdude]

Why? Because I'm an engineer and nothing else.

Get your geek on anytime you have the itch. I get it. Just understand that we need ballpark #s.

For CH, we need to know it's about 400 and not 50 or 1000. A 375 and a 400 are the same for what we are doing. Zeroing in to 390 wins no prizes.

For FC, well, this one is a pet peeve of mine. Whatever comes after the decimal point is meaningless IMO. A 2.5 and a 2.8 equally suck. By comparison, a 9.5 and a 9.8, are equally awesome for most CYAs.

 

[rack04]

The only additional point I would add is as water temperature decreases your CSI will go lower (negative) but that is fine. I tend to keep my pH around 7.8 as water temperature decreases to avoid going below negative 0.3 on CSI

It would be good to test your tap water (fill water to your pool) for TA and CH to determine how that affects your pool chemistry.
I run my CH at 350 for most of year so that is fine. Having a CYA of 60 with LC is great.

I just checked my fill water and the TA is 90 and CH is 150.

 

[pjt]

I have a large pack of cal hypo shock I could use to raise the CH if necessary.

I just checked my fill water and the TA is 90 and CH is 150.

Don't add any calcium. CH of 360 is great. Expect the CH to slowly increase over time due to the calcium in your fill water.

 

[JJ_Tex]

Those numbers look great. Only 2 comments:
- a CYA of 60 is perfectly fine with our summers so not sure I would intentionally do a water exchange to get it to 40 if you pool gets any sort of direct sunlight.
- Your FC is right in line with the published Target FC. Is your test before or after adding chlorine? If before, then great. If you are only dosing to the 8.4 FC, I would consider dosing to 9 or 10 and letting it drift down to the target range. Don't be afraid to run it a bit hot to give yourself some insurance (just look at my avatar).

 

[rack04]

Those numbers look great. Only 2 comments:
- a CYA of 60 is perfectly fine with our summers so not sure I would intentionally do a water exchange to get it to 40 if you pool gets any sort of direct sunlight.
- Your FC is right in line with the published Target FC. Is your test before or after adding chlorine? If before, then great. If you are only dosing to the 8.4 FC, I would consider dosing to 9 or 10 and letting it drift down to the target range. Don't be afraid to run it a bit hot to give yourself some insurance (just look at my avatar).

My pool gets a lot of sunlight, so you're probably right about keeping the CYA around 60 and maintaining the FC at 9-10. I assume I can use dichlor/trichlor tabs occasionally to bring the CYA back up. Especially, when we're travelling. Great question about the FC. 8.4 was before I dosed to target 9.

 

[Tomk2]

My CYA seems to decline faster than references predict. So I will use a puck a few times a month, and anytime I won't be home to take care of the pool. My CYA levels are in the 40's now, and a puck every two weeks plus some liquid 2 or three times a week seems to keep the chlorine around 6 or 7 at the end of the day. My CH has climbed over 500, so you are doing great being down in the 300's. I will do a drain and refill in the spring. Late fall and winter make the pool care so much easier than those brutal summers. Low water temps really make hitting a target saturation index so much easier. As your saturation index creeps up due to rising CH, you can let the alkalinity drop to keep the pH lower, and that will make hitting a target saturation index in the hot summers easier. My pool care with my local hard water got a whole bunch easier once I lowered alkalinity into the 60's