what order to add the chemicals

[alisonquilts]

Hi y'all,

We got 4 inches of rain two nights ago so I am currently getting my pool chemistry back to perfect. We have been working to lower the Ca++ for several months (currently at an almost reasonable 320 ppm, down from the crazy high 420 ppm of two months ago), so as the rain came down we pumped water from the bottom drains to keep from overflowing. This helped lose calcium, but of course it also dropped other stuff!

As of last night our readings were: FC 2.0; CC 0; pH 7.5; TA 55; Ca++ 320 and Cya 52.

I added cyanuric acid this morning (4lbs), and boosted the chlorine generator to 100% output to get the Cl- up. I am about to go out and test everything to see where I stand now. I am expecting that I will need to increase TA, and probably pH.

I have two questions:
1. What order should I add the new stuff? I know I read on here somewhere that certain chems should not be added too close together or you get precipitation, but I can't find that thread right now.
2. If I need to raise the pH how do I determine how much borax to use? (I haven't used borax before, since I haven't had the pH go low since I've been using the BBB method).

Thanks!
Alison

[alisonquilts]

OK, figured out the borax question (duh, use the pool calculator!) and have added the borax, because the cyanuric acid did indeed drop the pH further. But I still wonder, in a perfect world what is the ideal order for adding the chemicals?

=======================================

Thanks Big Dave.

The pH I gave was from before the cyanuric acid went in - the after value was 7.3. I found the answer to determining the amount of borax (duh -the Pool Calculator!), but I am still curious what the order should be for adding chemicals, even though the answer is now

Alison

[BigDave]

At pH 7.5, I don't see why you'd raise it, that's perfect for most. Your SWCG should tend to push pH up but the relatively low TA should reduce pH rise. Sounds to me like you're in a pretty good place - you've already addressed the CYA and FC issues.

[PoolDoc]

Alison,

I'd really, really encourage you to abandon the idea of an "ideal" or "perfect" order of things. We've found that, when people pursue pool perfection they almost always end with over-testing or over-treating their pools. What you want is 'good enough', not perfect.

The whole idea of a "perfect way to operate your pool" assumes that we know far more about pools and water chemistry then we actually do! If your water is clear and comfortable, and not damaging your pool, or costing too much time or money . . . that's optimal!

[alisonquilts]

I'd really, really encourage you to abandon the idea of an "ideal" or "perfect" order of things. We've found that, when people pursue pool perfection they almost always end with over-testing or over-treating their pools. What you want is 'good enough', not perfect.

I appreciate that, PoolDoc, and it is certainly the approach I generally take in life! The only reason I am so curious is that I am sure I read a thread which mentioned a couple of chemicals that would precipitate if you added them too close together (but I can't remember which ones), and I also thought I read a thread which suggested that it is important to get your (pH/cya/TA) in the right ballpark before adjusting your (pH/cya/TA) because of the way they interact. I just can't remember the threads accurately!

It isn't perfection driving my question, it's memory impairment!

Alison

PS And since I have started following the advice of this forum, and testing my own water, I have become a much more serene and confident pool owner, and my pool has been much more stable. Thank you!

[aylad]

You don't want to test or adjust pH if your chlorine is high, because the pH test results will be falsely high. So if you need to adjust pH, do it before you shock the pool. Also, if you have a high calcium level, adding cal-hypo or baking soda/alk up can cause cloudy/milky water problems. Other than that, everything else should work out okay...

[alisonquilts]

Great! That is exactly what I wanted to know. Thanks!

Alison

[TheKs]

Aylad,

You said: "You don't want to test or adjust pH if your chlorine is high, because the pH test results will be falsely high. "

What level is considered "high" for the chlorine?

Peggy

[Charlie_R]

In my own small pool, I've noted that the pH false readings seem to start for me at around 30 - 35ppm FC. I don't know if it would be true for a larger pool, though. Another thing I've noted is when the FC is high, the pH test tends to climb the scale over time. The higher the FC, the faster the climb. At 50 FC, it is a noticeable color change. Like within seconds, the color will change from 7.2 all the way to above 8.0. Where at 30 FC, the change creeps up on you, taking 2-3 min to go from 7.4 to 7.6.

As I said, this appears to be true for a ~4.4k gal pool, but as I have nothing to compare it to, I don't know about larger or smaller pools.

[Watermom]

With a Taylor K2006 kit, you can test pH reliably up to about a chlorine level of 15. This is not true for other kits, though.

(It doesn't have anything to do with the pool's volume, by the way.)

[Charlie_R]

I was just thinking that the water volume difference would have bearing on it, that's all.

Thank you, Watermom!

[PoolDoc]

The only reason I am so curious is that I am sure I read a thread which mentioned a couple of chemicals that would precipitate if you added them too close together

That's when you add calcium PLUS either sodium bicarbonate (Alk Increaser) or sodium carbonate (pH Increaser) at the same time. You have a vinyl pool, so you NEVER need to add calcium. (Problem solved!)