New pool owner, would love to run my plan by you

lhlsea

Bronze Supporter
Apr 28, 2017
29
Seattle, WA
#1
Hello all, first post here, from a new pool owner in finally-sunny Seattle. I moved in to my place in September, spent a bit of time learning the ropes with my pool for a month or so briefly, then didn't touch it much throughout the winter. I am ready to give it a go this weekend.


I've read quite a lot on this site over the past several months (thank you so much) and have the awesome PoolMath beta app going, so feel like I have some basic knowledge but little practical experience or judgment. I was hoping I could run my plan by you.


Pool is 17k gal plaster, non-SWG. Started to build up some algae in the past week. My tests a few minutes ago (Taylor K-2005) show:


FC 0
pH ~8.0*
TA 60
CH 160
CYA ~25**
Temp 60
(CSI = -0.22)


* doing the kit's acid demand test showed one drop would bring me down to 7.7, two drops to 7.4
** at 30 it was quite cloudy but the dot wasn't totally gone


The main thing I feel like I don't understand well is the order of operations. Here's my guess from my reading on what my plan should be (in this order):


1) bring pH down to about 7.4 using 30 oz Muratic Acid (31.45%). I've used MA one time back in October, and just added 15 oz a few minutes ago.


2) SLAM. The app says that I should target 12 and use 312 oz of the batch of 8% bleach I bought at Costco last weekend. Wondering if I'm ok to go for it at this CYA level even though it's a bit low.


3) Start maintaining chlorine. Prior owners left a small batch of the trichlor pucks they had been using with a floater (the Costco clorox ones which I used for awhile after we moved in before stopping for the winter). I am ready to switch over to bleach as you all recommend, but was wondering if I should just use up my pucks until my CYA rises some, then switch to bleach.


4) Bring up TA with baking soda.


5) Bring up CH with Calcium Chloride.


6) Keep on it.


Am I anywhere close, especially with the order?

Thanks so much for any advice - much appreciated!


-- Lewis
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,327
San Dimas, CA (LA County)
#2
Odds are you'll lose a bunch of water from backwashing during the SLAM, so everything's going to be out of whack when it's done. When it passes all three tests, you let the FC drift down below 10 and retest everything. Then you can plan the rest of the attack.

pH first, then take FC to shock level and maintain it there. But I see a problem. The K-2005 doesn't measure FC up to where you need to take it. The usual scenario is that you went to the local pool store and asked for the K-2006 FAS-DPD test kit and they sold you a K-2005 DPD test kit assuring you it was the right one. It's not. Good news is, you can buy just the FAS-DPD test separately.

I would hang onto those pucks for vacations. They'll keep for years if you leave the bucket lid tight. CYA is very acidic and you'll constantly be dealing with dropping pH and TA, plus they'll take a while to dissolve and get you up to the 40-50 range. But certainly you can use them if you want to. We're not opposed to pucks if you need the CYa and the acid. Just be sure you need what they add.
 

lhlsea

Bronze Supporter
Apr 28, 2017
29
Seattle, WA
#3
Thank you very much Richard.

You were close on the test kit -- I bought it prior to discovering TFP, from the pool guy who has been helping me with my equipment (he's been great, though, and though he services pools has encouraged me to try to do it myself, and most of his recommendations are relatively close to what I've seen here at TFP). I'll see if the local pool store has FAS-DPD so I can try to SLAM this weekend.

If I hang on to the pucks and switch to bleach now, should I add CYA now (and do I do that before or after SLAM)? My CYA test was 40 a week ago and a best guess of 25 today (but perhaps I didn't do the test properly, as I was surprised by such a big change in one week). I haven't added CYA before so that would be new to me.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,327
San Dimas, CA (LA County)
#4
Thank you very much Richard.

You were close on the test kit -- I bought it prior to discovering TFP, from the pool guy who has been helping me with my equipment (he's been great, though, and though he services pools has encouraged me to try to do it myself, and most of his recommendations are relatively close to what I've seen here at TFP). I'll see if the local pool store has FAS-DPD so I can try to SLAM this weekend.

If I hang on to the pucks and switch to bleach now, should I add CYA now (and do I do that before or after SLAM)? My CYA test was 40 a week ago and a best guess of 25 today (but perhaps I didn't do the test properly, as I was surprised by such a big change in one week). I haven't added CYA before so that would be new to me.
CYA doesn't go away except from splashout, backwashing, or overflowing from rain. Or intentional draining. The test, however, can be a pain. You need to do it in full sun. Even the difference between indoors under bright lights and outdoors can be huge. There's no shame in pouring the sample back and forth a dozen times if that's what it takes to feel comfortable with the number. If you try the search box for CYA testing and maybe include dot, you'll get so many results it will astonish you. Pick something recent and see all the various techniques.
 

lhlsea

Bronze Supporter
Apr 28, 2017
29
Seattle, WA
#6
Made it to the pool store this morning and they had my CYA at 45 so I feel better that it's in a reasonable range for a SLAM.

One minor question I have -- the store didn't sell the FAS-DPD as a kit, but they did have the R-0871-C titrating reagent and the R-0870 powder. So I bought those. I already have R-0003 from my kit.
What they didn't have was a small comparator tube that normally comes with the kit you linked to.

I just tried the test using my K-2005 comparator (25ml line). Any concerns about this or now using the comparator for other tests? I wasn't sure if this test really needed its own comparator for some reason.

(Oh, and my FC was at 20 so the four jugs of bleach have me off to a good start!).

Thanks!



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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,327
San Dimas, CA (LA County)
#7
One minor question I have -- the store didn't sell the FAS-DPD as a kit, but they did have the R-0871-C titrating reagent and the R-0870 powder. So I bought those. I already have R-0003 from my kit.
What they didn't have was a small comparator tube that normally comes with the kit you linked to.
The tube will tend to get cloudy with time for some reason, which is why the TF100 comes with a dedicated cylinder. It's no big deal.