CH of 160, should I raise it?

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David ATX

0
Sep 1, 2017
21
Austin
Hello,
I tested my water this morning (Taylor K-2006) and here are my numbers:

FC: 5
CC: 0
Ph: 7.8
TA: 70
CH: 160
CYA: 60

My pool is pretty new, startup was just after the 4th. I just added 25 oz of 12.5% bleach to raise my FC to 7 (my typical daily dose), and I plan on adding some MA later today to bring the Ph down (my pool is an acid eater, my Ph is constantly rising).

However, I'm more concerned about my CH level. According to PoolMath, I should be between 250-350, so I'm wondering if I should start raising my CH level, and when? My water is crystal clear, although I am noticing some white stains (I assume are calcium stains?) along the waterline in the spa and on some of the flagstone. Any help would be appreciated, thanks!
 
Did you have high calcium levels recently (from the scaling that you are describing)?

I think as long as you are in the -.6 - .6 CSI range will be OK. I fought high CH for WEEKS because of a new pool and excess shocking done by my pool builder. It has only recently dropped down to the 200 levels, but during that time I just ensured that my chemicals stayed in balance and I stayed within the recommended CSI levels.
 
No, I tested my CH a few weeks ago and it was at the same level, but we had just gotten dumped with rain so I thought that might be the case for it being so low, so I figured I'd give it some time. It looks like my CSI range is okay at -0.29, according to PoolMath. So if my CSI level is within range, I shouldn't stress about my low CH?
 
Here are some pics of what I'm describing. The waterline is very faint, and I'm about to take a pumice stone to it. Hopefully these pics can better represent what I'm talking about. However, given that my CH level is so low, I'm not sure this is scaling:
 

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David ATX said:
Hello,I tested my water this morning (Taylor K-2006) and here are my numbers:FC: 5CC: 0Ph: 7.8TA: 70CH: 160CYA: 60My pool is pretty new, startup was just after the 4th. I just added 25 oz of 12.5% bleach to raise my FC to 7 (my typical daily dose), and I plan on adding some MA later today to bring the Ph down (my pool is an acid eater, my Ph is constantly rising).However, I'm more concerned about my CH level. According to PoolMath, I should be between 250-350, so I'm wondering if I should start raising my CH level, and when? My water is crystal clear, although I am noticing some white stains (I assume are calcium stains?) along the waterline in the spa and on some of the flagstone. Any help would be appreciated, thanks!
Click to expand...
When I put your test results into poolmath I get a CSI of -0.2 (using a temp of 86F), which is OK, but you don't want it to keep going more negative. If you were to raise it to 250ppm, your CSI would be -0.01, but don't feel like you have to run out and add any CH right away.
 
While I agree with that, that's based on a Ph of 7.8. As mentioned in my initial post, I'm constantly fighting high Ph (not sure why), so when I add acid to reduce Ph where I'd like it to be at 7.4, my CSI drops down considerably, albeit in range, but at the low end of the range.
 
Why do you push the pH so low? If you target 7.6-7.8 you will probably find that the rise is not so fast. pH tends to rise quicker in the lower end of the range, slowing as it approaches 7.6-7.7. If your CSI is good, a pH of 7.8 is fine.

As I said earlier, you could raise CH up to 250ppm if you like, your CSI will be closer to zero. But if that is calcium scale in your pics, you would be better off with a slightly negative CSI to be a bit aggressive to the scale.
 
Hard to tell from the pictures but the white areas appear to be on the stone? If so - most likely efflorescence. It is from water behind the stone bleeding through and carrying minerals from the stone to the surface. Properly waterproofing the base area behind the stone will slow or stop it.

Take care.
 
Thanks all for the replies.

I did add about 22 oz of MA today to bring my Ph down to 7.4 (this was done prior to domct203's suggestion). I'll revise my Ph target to the 7.6-7.8 range and see if that holds stable, but I find that I will creep into the 8.0 range within 4 days of adding acid.

mknauss, I did a quick Google search of efflorescence, and I believe that's what I'm seeing on the flagstone. As mentioned, the pool isn't 3 months old yet, so I assume this is a result of that. I seriously doubt my PB waterproofed the base area behind the stone, if the problem persists I'll have to look into that.

Thanks again for all the responses.
 

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Even a pH of 8 with the low CH has your CSI in range.

I would imagine you get a fair bit of evaporation and have hard water ... so the CH is going to continuously climb. I would not raise the CH faster ... in fact I am in the same boat, although my CH is currently even lower.
 
David ATX said:
Thanks all for the replies.

I did add about 22 oz of MA today to bring my Ph down to 7.4 (this was done prior to domct203's suggestion). I'll revise my Ph target to the 7.6-7.8 range and see if that holds stable, but I find that I will creep into the 8.0 range within 4 days of adding acid.

mknauss, I did a quick Google search of efflorescence, and I believe that's what I'm seeing on the flagstone. As mentioned, the pool isn't 3 months old yet, so I assume this is a result of that. I seriously doubt my PB waterproofed the base area behind the stone, if the problem persists I'll have to look into that.

Thanks again for all the responses.
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Your pH is most likely going to climb, but it should climb slower.

What is the CH, TA & pH of your fill water?
 
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