Help this n00b fix their pool

Apr 25, 2017
25
Georgia
#1
Firstly, I've operated a pool for all of 3 weeks now and I admit it - I've already made several mistakes. The two biggest were:

1) Not doing enough research first (ie, reading this forum) and;

2) Listening to pool store associates (never again)

That said, here are my stats:

In-ground, vinyl lined, SWG system, ~22,000 gallon pool
FC = 14 ppm
TC = 14 ppm
Salt = 3100 ppm
CH = 140 ppm
CYA = 110 ppm !!
TA = 100 ppm
pH = 7.5
Copper, Iron = 0
Phosphates = 500 ppb
Temperature = 70F

As you can see, I've got high CYA. Did I mention I have a vinyl liner? Did I mention salt water? Did I also mention my pool is 50 years old and has no main drain?

Brief background story if you care to read: opened pool about 3 weeks ago, immediately converted to salt water because it's easier and less chemicals right? (first mistake - now, what do I *do* with my salt water?) Cleaned and tested daily for a week and a half. Left town for 2 nights / 3 days. Came back to failed capacitor, pump had stopped running, had beginnings of algae growing on water surface. Went to pool store (second mistake) where I was advised to shock with... you guessed it, CYA-containing Chlor-Brite. I didn't even know what CYA was at this point (first mistake again). This shock occurred Saturday. As you can see, my chlorine levels are still very high. Algae has begun to grow again on water surface since the high CYA is making my chlorine inefficient, plus high phosphates. Took a water sample into pool store for the readout given above.

My DPD test kit doesn't do CYA, so I bought the strips. I tested an undiluted sample for CYA (tested between 100-150ppm). I tested a diluted 1:1 sample for CYA (tested between 40-100ppm). Finally, I tested a diluted 2:1 sample (tested below 40ppm). So the 110ppm CYA level seems to check out based on these 3 measurements.

Now that I've done my reading, the consensus for high CYA is to drain/replace. Pool calculator says I need to drain roughly 25% and replace. But I can't drain without ruining the vinyl liner, I also have salt-laden water that I can't simply dump in my yard, AND I have no main drain and the only pump intake is located at the skimmer, so I can't drain past that level without a submersible pump.

I will defer to the thoughts of other more experience pool people here, but as of now I see two main options:

a) Use submersible pump to pump out 1-2 feet of water at a time, before vinyl starts to sag, and replace with new water. Repeat 4+ times until CYA is 70-80 ppm or;

b) Fill the pool up to the brim and backwash back to normal levels an estimated 8+ times.

Any other thoughts, advice, or general derision?

Also, for other salt water owners, where do you drain backwash? I'm not keen on salting my lawn.
 

duraleigh

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Apr 1, 2007
31,333
Sebring, Florida
#3
You need one of the two testkits we suggest in Pool School. No more guesswork. No more depending on goofballs to test your water.

We'll help you every step of the way.....promise.
 
Apr 25, 2017
25
Georgia
#4
Ok, I've done 2 rounds of major draining (about 1.5-2 feet down) plus 2 "backwash" drains. I also received my TF100 test kit, magnetic stirrer and drop salinity test.

Boy, that CYA test is a tough one. Do you guys do this inside under artificial light? I'm not always able to test during daylight hours. For consistency, I've done it inside, not directly below a light, with a white piece of paper under the vial. I also pour until the black dot is completely gone, not even the faintest outline or shadow, just milky testing fluid. This takes skill and some subjectivity as I'm pouring drop by drop at the end. I've been testing 4 times each just to ensure consistency.

That said, here are my new results:

FC = 9.5 ppm
CC = 1 ppm
Salt = 2000 ppm
CYA = 80 ppm
TA = 80 ppm
PH = ~7.3
By the way, upon receiving the TF100, I tested the original water @ CYA of ~120ppm, via dilution test, and around 18 ppm FC, 0 CC.

So what now? At a slightly lower CYA, I believe the FC should begin coming down, especially with a few sunny days in the forecast.

Pool calculator says to add 5x 40lb bags of salt to get back up to ppm ~3200.

I'd also like to add borate as I hear this helps pH drift in SWG pools. I also understand it helps algae growth. What's a good borate target?
 

Flying Tivo

Well-known member
Jan 24, 2017
532
Monterrey, NL, Mexico
#5
I would hold on the Borates until you have at least 6 months of control over your pool chemistry. The CYA test has to be done outside with your back to the sun and the test at waist level. Make sure you glance not stare at the dot. You can add salt no problem with that. The only thing im missing is if you did the complete SLAM process? How is the water right now? Cloudy, clear?

Felipe
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
9,088
Evans, Georgia
#6
Well, lets put off the borates plan until you're all settled with the basic stuff first, ok?

CYA test has to be run outside, sunny day. Hold vial waist high, sun to your back. Fill to each line and glance at it. There are no test values between 40 and 50, or 50 and 60 for example. If it looks like it should be "45" its really 50. Then you use this to determine your FC needs: [FC/CYA][/FC/CYA]

Until you get all algae killed don't use the SWG but instead your gonna need to SLAM and that calls for liquid chlorine (aka bleach)

How did you test your salt level to determine how much to plug in to PoolMath?? Do you have the Taylor Salt Test Kit- K1776?

Maddie :flower:
 
Apr 25, 2017
25
Georgia
#7
Well, case in point on the borates - I can't even do the CYA test correctly yet. I'll wait on the borates. Will re-do CYA test tomorrow and report back.

How is the water right now? Cloudy, clear?
It's very clear. No SLAM process yet as I just "completed" the ill-fated pool-store-directed debacle of a shock. I read now that I should do an OCLT first to determine if I need to SLAM.

I will try get a picture of the stuff floating on the surface too, it's tough to see. I wonder if my sand filter just performs poorly, but I do note a small amount of brown "dust" when I brush the bottom of the pool. The pool is high debris and I'm vacuuming up leaves and tree pollen daily. I think I'll try out a finer skimmer net too.

Do you have the Taylor Salt Test Kit- K1776?
Yes.
 
Apr 25, 2017
25
Georgia
#8
Update:

I did an OCLT last night at 9.5 FC, then tested again this morning at 9.5 FC as well. My SWG is wired into the pump's switch, so it has to be on, but I had the sanitizer output turned completely off... allegedly. Perhaps I should do a test with the pump/SWG off all night.

I also re-tested this evening, prior to posting, stats are as follows:

FC = 9 ppm
CC = 0 ppm
CYA = 80 ppm
pH ~7.3

I feel confident about the CYA test. I did it outside in the late afternoon with back turned to sun. Poured to 100 ppm line, could still see the dot. At 90, still there slightly. At 80, very very faint, arguably gone. At 70, definitely gone. Thanks for this method, this made it much easier, letting everything settle each time then glancing and deciding.

On a sadder note, there was a drowned baby bird skimmed this evening. Fortunately, it was intact. Not a harbinger of fun.

Below are pictures of my water, the first where you can see the "stuff" floating on the water surface (there was far more after a rain), and the second to see the water clarity - vacuum at max depth ~8 feet. I want to maintain my FC at about 6 for my CYA level, do I simply let it come down to that level, then adjust my SWG to maintain? Do I need to SLAM?

Also, a question on SLAM: the chart represents the target level FC, but you want to maintain that level until you pass an OCLT and CC = 0? So if pool calculator says 1000 oz 6% bleach to achieve sufficient FC level, you really need more than 1000 in order to maintain that level for as long as it takes to pass OCLT?

View attachment 60229 View attachment 60230
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
9,088
Evans, Georgia
#9
Oh good! Your pool looks nice and clear. The bits of schmutz floating are most likely bits of pollen and dust. I like to keep my pump on during high debris blowing days just to keep the skimmer working. You might want to add a skimmer sock or hairnet to the inside of your skimmer basket to help collect this stuff and keep it out of your filter.

For your CYA of 80, your target is 6, and you never want to go below 4. So we know that most pools will lose around 1-3ppm of FC daily (sacrifice to the sun gods) so having your FC at 8 or 9 is perfect. That way when you lose 2ppm, you still have that 6ppm left, right? Right!! [FC/CYA][/FC/CYA]

I'd keep up as you're doing cause your numbers look good. I don't believe you need to SLAM since you passed the OCLT.

Maddie :flower:
 
Apr 25, 2017
25
Georgia
#10
Question:

We've had rain the past few days and each day the pool is registering about 0.5ppm of CC. Is that normal for rainy days with lots of leaf debris in the pool? Is it indicative of something else?
 
Apr 25, 2017
25
Georgia
#12
Update:

Got FC down to 6 and turned on SWG. 20% output for 8 hours during the day seems to do the trick. I test in early evening, no direct sun on pool, about 2-3 hours after pump/SWG goes off. It's been testing in the 4.5-5.5ppm range at day's end for 5 straight days. No CC.

pH has crept up to about 7.6 now. How high should I let it go before I go get the muriatic acid? 7.8? Do I reduce and add borates? What's a good borate level?

Other stats have been consistent:

Salt = 3000 ppm (added 200lbs post-drain)
CH = 150 ppm
TA = 70 ppm

The SWG has been a bit finicky in terms of recognizing the 2900 minimum. It seems to be producing chlorine fine, but I've got the red low salt light even with confidence in the 3000ppm test result. Is it okay to run it like this?
 

n240sxguy

Well-known member
May 17, 2014
1,802
Benton, KY
#13
I'd lower it a little when it gets to 7.8. I'll let someone else address the borate level. All I know is 30-50ppm is the recommended level. If the swg doesn't like 3000ppm salt just bump it up to 3200-3300. Won't hurt a thing. Unless it gets way off then just keep the swg happy.
 

drharris

Well-known member
Jun 29, 2016
275
Walhalla, SC
#15
The SWG has been a bit finicky in terms of recognizing the 2900 minimum. It seems to be producing chlorine fine, but I've got the red low salt light even with confidence in the 3000ppm test result. Is it okay to run it like this?
I find my Intellichlor SWG really benefits from being on a good "schedule" when the water temps are floating around 70. It measures every 12 hours or so, so if you turn it on at 3pm one day, it's going to show a red light when it re-measures at a much colder 3am. I find trying to get it on a 10am/10pm schedule works pretty well. You have to restart the unit to do this (I just flip the breaker on my whole equipment pad, wait a few seconds, turn it back on). It won't hurt you to add just a bit more salt. A few backwashes and you'll have to add some anyway.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
9,088
Evans, Georgia
#16
Remember that for your CYA level ideally you want to keep your FC up at 6ppm. 4ppm is your bottom line and you're skirting that a bit too closely. I think going for 7ppm FC is a safer place to be especially as things are warming up (and sunny-ing up) here in Georgia.

I'd also suggest tossing one more bag of salt in just to keep the little guy happy.

Maddie :flower:
 
Apr 25, 2017
25
Georgia
#17
Ok, I did up the SWG sanitizer output to keep FC in the 5.5-7ppm range. However, I am now starting to see what appears to be green algae, mostly in "dead spots" that can't get good circulation. I noticed something was amiss yesterday when I went to brush and vacuum - the sloped sides of the pool in the more shaded areas had a visible brownish discoloration that went away after brushing and vacuuming. The brushing turned it into a fine mist in the water, which I assumed (hoped) was just dirt or pollen. Today, I noticed several unmistakable green spots on the liner in these same areas. The water is still crystal clear. On Monday night I passed an OCLT.

FC: 6
CC: 0.5
pH: 7.5
CYA: 80
Salt: 3000 ppm

I took pictures, but it's very difficult to see (see below). What do I do? Do I need to SLAM?
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
9,088
Evans, Georgia
#19
Try adding some liquid chlorine to bring it up to SLAM level, brush it really good and see if that helps? You may be still keeping your FC a bit low for whatever reason your pool needs a little extra.

You can increase your pump time or increase your SWG % a bit to see if that helps. And make sure you brush often, at least those areas with poor circulation.

Maddie :flower:
 

drharris

Well-known member
Jun 29, 2016
275
Walhalla, SC
#20
Also, you should test one day at the end of the timer's off cycle - basically, what is the lowest FC during the day. If it's ever dipping below the minimum, you need to adjust when the timer runs. I know I have to run mine during daytime/peak hours since that's when the FC drops... I can't rely on it to just tank up at night and then last through the day. Yours may be similar.