Getting The Chemistry Right

[Lou Erickson]

I got home from my trip, so I, my TF-100 test kit, and my pool were all in the same place. I went out to test the water, and found a light dusting of green on the stairs and the shallow end.

I brushed the pool and tested the water.

FC 4
CC 3
PH 7.5
TA 170
CH 550
CYA 50

The color-matching K1000 test gave me that PH, and a "Chlorine" of 0.5. Not sure how that relates to the numbers the drop tests gave.

I'm a little worried about the numbers, as I've not run the tests before. I'll run them again tomorrow and see how they look.

I'm surprised CYA is so low. It's on the high end of what's suggested, but this pool has never had anything but 3" tablets in the floater, and I'm surprised it isn't worse.

CH seems high, and that's an issue because a full drain isn't possible - water restrictions make that so. I can have the water filtered via reverse osmosis, as there's a new company in the area that will do that, if that's needed.

PH and TA are both high - TA more than PH.

FC is a touch low, but may fall fast - there's green.

Green means time to SLAM. Have to get some chlorine.

What else do I need, and what to do first?

I took a picture; I'll get it posted in a bit. You can still see the bottom, just a dusting of green on the stairs.

 

[Texas Splash]

You nailed it - SLAM via Pool School - SLAM - Shock Level And Maintain. Follow each step carefully and it will work. But don't leave anything out. Adjust pH down slightly as noted on the instructions then keep your FC at the required FC level until you pass all 3 SLAM criteria and you'll be fine.

 

[Lou Erickson]

Here's a before picture, because everybody likes pictures:




(Clicking should go to Flickr, where you can zoom or find a huge original size.)

Today looks about the same, but that I brushed all the algae off. A little in a few corners, but you can still see the bottom.

 

[Texas Splash]

Nice pool! Good pic as well. It will come-in handy later as you compare the changes.

 

[Lou Erickson]

Why, thank you. I was not looking for a house with a pool, but since we have one I want to keep it nice and be able to enjoy it.

I do think the pictures are useful, and made a note of where I stood to take this one so I could take similar ones in the future.

I only got chlorine this afternoon, and haven't added it yet; I wanted to get the PH adjusted first.

I added Muriatic Acid. (It's one thing the Pool Store sold me that is part of the TPF method!) Pool Math gave me an amount, and I used 2/3 of that, and it wasn't quite enough, just as predicted. I've just added the rest, and will check it here shortly. I expect the Ph to be at 7.2.

I took a set of measurements:
FC 1.5
CC 1
Ph 7.5
TA 210
CH 550
CYA 80

I don't think the TA or CYA have changed; I think it's me getting used to the test. CYA is particularly iffy. I had better light today, and got higher readings. In four readings, I got 60, 90, 80, and 80.

Honestly, the higher CYA makes sense because the pool's been chlorinated with pucks for, as far as I know, forever.

A Shock value of 31 will be a pain in the butt to keep up, but I don't see much alternative now. Draining half the water is possible, but refilling it isn't allowed; water restrictions. In a month or so, I can have the pool water cleared through reverse-osmosis, as a local company will start offering that service. Both the CH and CYA would benefit, but I don't know the cost yet.

 

[Catanzaro]

Is it possible, the 3" tablets are Cal-Hypo and not Tri-Chlor or Di-Chlor? Can you check to see what you are using? Your CYA is low compared to CH, unless California water is hard? NJ water is soft. When you perform the CYA test, keep doing it with the same water until you become comfortable. Pour solution slowly as the black dot starts disappearing and then come to a conclusion. CYA of 80 or 90 can still be managed. Maybe have a another eye.

Based on the picture, this should not take long for the SLAM process.

 

[Lou Erickson]

Is it possible, the 3" tablets are Cal-Hypo and not Tri-Chlor or Di-Chlor? Can you check to see what you are using? Your CYA is low compared to CH, unless California water is hard? NJ water is soft. When you perform the CYA test, keep doing it with the same water until you become comfortable. Pour solution slowly as the black dot starts disappearing and then come to a conclusion. CYA of 80 or 90 can still be managed. Maybe have a another eye.

Based on the picture, this should not take long for the SLAM process.

I think I'll get another pair of eyes to run the test and see if they measure like I do. That's a good idea.

I don't know what the tablets are, but I can ask the Pool Guy who's been providing them.

Our water is on the hard side; we get scale on everything in the house. I don't have a water softener. I could try the CA test on some tap water.

 

[Catanzaro]

When you speak to the "Pool Guy", please ask him if he came over to test water and take care of pool while you were gone? Were you gone long?

 

[Lou Erickson]

Catanzaro: I was out of town for one week. He was here and scrubbed the pool - he dates a sheet in the pool room. He probably added one gallon of liquid chlorine, and refilled the tabs in the floater. That's his usual process. It clearly wasn't quite enough with our highish CYA and all the sunny days last week.

I'll try and catch him tomorrow - he's very quick, and comes very early. I'll ask him what he put in the floater, and let him know I'm taking the pool over. We'll settle up and it'll all be me.

Measured chlorine levels:

FC: 20
CC: 2.5

Lots of loss, which I replaced. Pool Math tells me 2 gallons, so in went two gallons.

The first dose was 5.25, for a total of 7.25G of 10% today. I'm all but out. Hopefully HASA will be open tomorrow and I can get some of their stronger stuff, and that it'll be priced better.

Pump will run all night.

 

[Catanzaro]

Lou Erickson:

Good morning. Something is definitely going on as your CC (combined chlorine) is bouncing all over the place.

First test @ 3
Second test @ 1
Third test @ 2.5

Please keep a timeline of all your testing during the slam so you can look back.

 

[duraleigh]

Lou Erickson,

It sounds like you might be "winging it". Follow the SLAM article in Pool School to an absolute T. Don't vary from what the SLAM article instructs and your pool will get clear. Ask lot's of questions

 

[Lou Erickson]

I do understand the process; it's pretty clear. More likely I'm misreading the tests. I think it was operator error, and that I'm getting better at the process.

Yesterday wasn't good for the SLAM, as I wound up working an 18 hour day. I did manage to take a measurement at 11:10 am, yesterday:

FC: 6
CC: 1

I added chlorine to get it back to the SLAM level of 31. I then was called into the office and stayed there till after 1:00am. Since I had a 9:00am start, I didn't mess with the pool, I just fell over.

This morning, I measured at 10:10 am.

FC: 6
CC: 1

That's after 24 hours, and a long, hot, sunny day.

PoolMath told me how much chlorine to add, and I did that. I'll see if I can run out and test again now.

 

[Texas Splash]

Not much you can do when work calls. But by now you probably know that consistency and maintaining the SLAM FC level is key to a SLAM along with the continuous scrubbing, vacuuming, filter cleaning, etc. If you ever have questions about a test, let us know. We can't call-in sick for you with the boss, but we can give you advice on your pool.

 

[Lou Erickson]

Yeah, days like yesterday happen once in a while

I didn't mention it, but I did brush the pool at 10am today.

I just took another set:

FC: 26
CC: 1.5

It is a very hot sunny day today.

First time PoolMath has told me to add less than a gallon. Yay!

I'm working at home today, so should be able to check it more frequently.

 

[Lou Erickson]

Fresh test at 5:45pm. Still burning through chlorine, although there was direct sun on the pool much of the day, and a very bright, hot day it was.

FC: 22
CC: 1

Followed PoolMath's directions to get it back to shock level.

The direct sun is off the pool for the night - is that late enough to count for an OCLT or should I wait for it to set entirely? I'll probably do another check, anyway.

I don't think I'm there yet, but would like to see how it goes overnight.

I can't take a good picture any more, as the camera focuses on the top of the water and everything else is out of focus. Hrm. The water is startlingly clear.

 

[Lou Erickson]

Test at 10:00pm. Full dark. Tested after I spent an hour in the pool, finally being cool. Hot day. Still 85F outside. The pool was about the same.

Our floodlights light up the water so you can see the shadows of the ripples on the bottom of the pool. It's really neat.

They also reflect light off the pool onto the bottom of the palm trees, which is also sort of wavy and neat.

I need to go in the water more often!

I also need to find another hardware store, as this one is out of chlorine...

FC was 25
CC was 2 - I blame me for being a big ball of organics in the pool.

 

[Texas Splash]

Good morning Lou! Sorry I missed your last couple posts. You seem to be doing well. Because you asked, here is the link and some additional info on the OCLT when you think you are getting close to the end of the SLAM (no rush) - you'll know when: Pool School - Perform the Overnight FC Loss Test (OCLT)

When performing the OLCT, remember that it must be done when the sun has dropped – no sunlight on the pool. About 8 hours total is recommended. Also, your FC level should be elevated more than normal. Starting (bedtime) FC could be close to your SLAM level, but no lower than 10. Anything less and you may not receive an accurate portrayal of FC loss (by percentage), even if it’s only 1 ppm.

Have a nice day!