Any tips before this newb tries to do an OCLT

Jul 27, 2015
6
Pasadena, CA
First post, but I've been lurking for a bit.

We purchased an Intex Pool (in sig) in Early 2014.
Added an Intex SWG about a month later.
Never had any problems, but the only testing that I was doing was with HTH test strips.

Covered the pool when not in use, to avoid evaporating that we were experiencing.
We put on a winter cover in October or so.

I January we uncovered it and went swimming. The water was beautiful. clear.

In Spring my daughter and her friends uncovered it again and went swimming.
They didn't cover it back up for a couple of days.

My neighbors trees and wind and the pool being uncovered (then getting covered without vacuuming) were not a good combination.

Come June, I uncovered the pool, to find a huge amount of leaves and sand stuff on the bottom of the pool.


I vacuumed it up over 3 days, using my home made, ghetto tool:
big V8 bottle with the bottom cut out, with a window screen material placed inside, placed over the water outlet (pool outlet/ pump line inlet).
I replaced my tool with a Zodiac Cyclone and proper Intex skimmer hose adapter since then :)


The kids had left old, sun damaged pool noodles in the pool, so there were a ton of microscopic (to me) noodle pieces in the water along with other solids.

I got tired of cleaning the paper filter every hour or so, so I bought a sand filter.

I don't have readings from that time, but did the mistake of listening to Leslie's reps who were selling me things that might have helped some, and made things worse.

(like adding soda ash, when all I had to do was aerate the water as my TA was high)

I finally ordered the Taylor K-2006-Salt kit.

I did a comparison:
Test Strips:
(Tap Water)
TH 400
FC 0
PH 7.2-7.5
TA 120-180
CYA 0-30

(Pool Water)
Salt 2500-3000 (added a bag to bring it up to 3400)
TH 400
FC 1-2
PH 7.5
TA 180
CYA 0-30
Copper .1-.2

K2006 Test Kit:
(Tap Water)
TH 425
FC 1.5
CC 0
PH 7.8
TA 150
CYA 0-30

(Pool Water)
Salt 4200 (after I added a bag )
TH 450
FC 4
CC .5
PH 7.4
TA 190
CYA <30

I was still using the stuff from Leslie's (conditioners, soda ash, dry muratic acid...)
Then I found links to this site (but still hadn't read through pool school yet), so I did things out of order.
Started a new log of pool tests:
8/7/15 @ 18:53
Salt: 21 drops (4200 ppm)
CYA 80-90 (Hard to say when that dot really disappears, I can still see it)
PH 7.8
FC .4ppm (very light pink, even adding 6 drops of the powder)
CC 0
TA 210
CH 475

Started adding a qt or liquid muratic acid (by far better and easier to use than that powdered, expensive stuff from Leslie's)
It would drop the PH.
I found that if I took the short hose that connects to the skimmer adapter and placed it on the water inlet and tied it up and let it splash in, I could raise the PH to 7.6-7.8 in about two days. I did this over and over until yesterday.

I added two bottles of Clorox and went to the Dodger game. I forgot to test my FC reading last night when I got home.
Beer will do that to you. No I wasn't driving :)

This morning I went out and took the following readings:


Salt: 20 drops (4000 ppm, the 19th drop is sort of blue, but the 20th is definitely blue, no changes after more drops are added)
CYA 80-90 (Hard to say when that dot really disappears, I can still see it) Test strip shows 30-50.
PH 7.5 (a shade in between 7.4 and 7.6)
FC 6.8 (I haven't seen it that pink in a while)
CC .6
TA 100
CH 450

Copper .2 (Intex Test strip)

The salt and Ch dropped a bit because during the previous procedures, I would backflush 50-100 gallons to clean the sand filter.
I bought two different hose threaded water filters and stacked them in series and fill with that water.
I don't have test readings for that water, but I do remember the CH was 300.

So I started to read through he pool school (I wish I would have done this at the beginning), and will plan to do the OCLT tonight, then know where I am at regarding needing to Slam and getting the pool to proper specs.

Any tips before I do so? (Sorry for the War & Peace novel)
Thanks,
David
 
It's looks pretty clear.

I can see the checkered pattern on the vinyl below.

I think keeping the pool covered really helps.

I put the original (vinyl? Plastic?) Intex pool cover back on along with a screened leaf cover.

The "winter" cover that we were using started to flake and collect stuff on it when the water was really bad.
The winter cover looks like those cheap blue tarps that you can bu at OSH or Harbor freight.

I did notice there is a vary small amount of dirt or sand in the creases of the vinyl on the bottom.
I'll try and take a pic tonight before and after I vacuum to show the clarity.
I'll also try to take a pic of the CYA test to see if I think it correct for the dot visiblity.


I want to add some DE to my sand filter, just not sure when to do it.
Before the OCLT? after OCLT? after getting the whole pool in spec?

Thanks,
D
 
You can add the DE now, just go really easy with it on that small sand filter and watch the pressure when you do for several hours. Start with 1/8 of a cup, mixed with pool water in a bucket and pour slowly into skimmer (you have a skimmer right?). Check the pressure rise after 30 minutes. You only want a 1 psi pressure rise. If you don't notice a rise with 1/8 cup (2 tablespoons), then try 1-2 more tablespoons.

Just make sure you test after sunset and test again before the sun is up too high. I would suggest bumping the FC to about 10 ppm, testing to verify the level for your night/evening test to start the OCLT. The OCLT is designed to be done as part of a SLAM, with elevated FC levels.
 
So I went out just before dark and took a pic before vacuuming.

BeforeVacuum.jpg

There was some sand, dirt and leaves in the creases, so I vacuumed it all up (or so I thought).

I then backflushed about 50 gallons and rinse another 50 then added 1/2 cup of DE.

I took an after vac pic.

VacAfter.jpg

I only had slightly less than a gallon of regular clorox (the other clorox we had was scented) so I added that.

After 30 minutes I covered up the pool and went inside.

Came out just before 9PM and took a sample of water.

PH 7.4
FC (43 drops) 8.6ppm
CC (2 drops) .4
TA 100 PPM

This morning, I went out around 6AM and took another sample.
PH 7.4
FC (30 drops) 6
CC .4
TA 100


So it looks like I still have something in there eating away at my Chlorine.
I'll go buy a bunch of clorox tomorrow morning.

I guess, it all depends on my CYA readings. What do you consider my CYA to be?
I can see the dot all the way through pic F. Does that mean it is 55-58?

CYA Readings-2.jpg
 
Hello D and welcome to TFP. Typically we round up or down they CYA (55+ would be 60, 54 would be 50, etc. The black dot should completely disappear. Here's a couple cut & pastes related to your two scenarios (CYA and OCLT):

When performing the OLCT, remember that if 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 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.

Proper lighting is important for the CYA test. You want to test for CYA outside on a sunny day, but keep the skinny view tube in the shade. Taylor recommends standing in the sun with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.

Hope some of this helps. Good luck!
 
Assume and treat the pool like it's 60 ppm CYA. So you should be SLAMing at 24 ppm FC.

Also, for sure during the SLAM, just use a 10 mL sample for FC/CC testing. Saves a lot on reagent drops.

1/2 cup of DE sounds like a alot for your size filter. Keep and eye on that filter pressure.
 
Yeah, I already had to buy the 32oz reagent for all of the CYA testing that I was doing to refill my two, small bottles.

Looks like I'll need about 3+ gallons of Clorox.

I really hate that stupid tiny 1" 60 psi gauge on the sand filter.

I think I'm going to replace it with a 2" 30 psi gauge.


Thanks for all of the help I'll check in later this weekend or Monday at the latest.
 

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