Starting numbers, issues

Jump to latest Follow Reply
O

Oscar7

0
Mar 16, 2015
10
South Florida
Hi, I'm Oscar, new to the board.

Just bought a house with an IG pool, and luckily it was in decent shape to begin with. Got my TF100 today, ran a couple tests more than once to confirm accuracy, here are my values today...

12,000 gal
80 deg F
pH 7.5
FC 13
CC 0
TC 13
CH 500
TA 90
CYA 100

I know CYA is high, debating dropping some water and refilling vs waiting for rainy season to kick in in a couple months here.
CH a little high too, same debate.

Previous owner had a pool company come weekly who used stabilized tablets in a floater, thus the high CYA. I left it until today when I could run good numbers myself, will now manually chlorinate, most likely with pool store liquid chlorine.

I understand the FC number is about right per the CYA chart, but does this not make the water seem overchlorinated to the swimmer? I've seen it said that over 5 ppm is high enough to close a pool. Pool math also tells me that shocking will take about 2.5 gallons, this is to be done weekly?

Got some other issues, but will get to that later, chemistry first, pic here... http://tinyurl.com/mmf27hy
 
Welcome to the forum!

If you replace water to drop the CYA, the CH will come down too.

As to your FC question, no, the swimmers won't notice because CYA buffers the chlorine. I usually keep my FC in the 8-10 range because of my CYA level, and nothing makes me happier than when guests say, "Wow, how do you keep your pool so clean without chlorine?"
 
Oscar7 said:
Pool math also tells me that shocking will take about 2.5 gallons, this is to be done weekly?
Click to expand...


Shocking is not needed with your levels and how your water looks. We really do not use the term shock. It is called SLAM. There is a link on how to do a SLAM but you should never need to do it if you follow the TFP way!

You will add chlorine daily to "feed" the pool. I add mine at just after dark and let the pump run for 30 mins. or so to mix it in (I run the pump during the day and turn it off when I get home). I do this to let the chlorine do it's job without worrying about the sun using it up.

I would go ahead and drain/refill your water to work on your CYA. Lower CYA will be cheaper and easier to maintain due to not needing as much chlorine. Here is the chart to show you the needed levels of chlorine for the different CYA levels.

http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

Your CYA may be even higher. You might want to do the 50/50 test. Here is a link to how to do it. Opps I cannot find the link. I hope someone will come along to show it to you.

Good luck and let us know what your other questions/issues are.
 
48 hours after my first post, I ran some tests and am writing this. Haven't added bleach since I pulled the trichlor floater 2 days ago. In 48 hours, FC dropped from 13 to 8.5. As per my previous CYA result of 100, I added about a half gallon 10.5% pool store chlorine to bring it up to a goal of 12. I tested FC again about an hour after adding, came up with 15. A little high, but I also probably poured too much bleach and will have to start actually measuring.

When I first tested CYA myself I got 100 right on the mark, which made sense because three tests done by local Pinch a Penny in the last 3 weeks all came up 95.

I just ran a CYA test and a 50/50 test back to back, and both came up 60. I removed the trichlor floater 2 days ago and replaced maybe 300-400 gallons, not a lot. Is there a reason for this discrepancy? I know its a somewhat subjective test and my eyes are pretty lousy for a 30 year old, but I ran it a number of times to the same result. Either way, my FC is high for the suggested 8 at a CYA of 60, though I'm adding about 300 gallons now and it should drop off soon enough.
 
Rely on your liquid bleach chlorine additions to TELL you whether your gallons are higher or lower than you THINK they are. Pool Math doesn't lie! If adding X amount of bleach should raise your FC by X amount for the gallons you declare and then it tests higher, your gallons size is obviously overstated.
 
Of all the tests the CYA is the most subjective. Lighting, where you hold the tube or several other issues will impCt the results. I ignore swings of about 5 - 10 myself, but I'm getting old with the eyes that go along with that. When you do the test you can pour the solution back and forth between the mixing container and the reading tube several times to get an average number.

I would ignore Pinch a Penny and their results as they are even worse at the test than we all can be. They are doing the test indoors under artificial lighting and I think that has something to do with it.

As woodyp said, if you pay attention to what pool math says should happen when you add chemicals and what really does happen you will get a feel for your pool volume and weather what you think it is is correct.
 

Enjoying this content?

Support TFP with a donation.

Give Support
MarianParoo said:
Maybe a dumb question, but when you did the dilution test, did you multiply your result by 2? Is CYA 60 or 120?
Click to expand...

I did multiply, CYA is 60. I did the test standing outside under shaded afternoon sunlight. I dripped test water into the view tube until the black dot was absolutely occluded and all I saw was uniform white. Ran 50/50 twice, both put the water right at 30 mark, then straight test brought water right to 60 mark. It would seem to me that the 50/50 is more accurate as the lines are far closer higher on the scale.
 
Oscar7 said:
I did multiply, CYA is 60. I did the test standing outside under shaded afternoon sunlight. I dripped test water into the view tube until the black dot was absolutely occluded and all I saw was uniform white. Ran 50/50 twice, both put the water right at 30 mark, then straight test brought water right to 60 mark. It would seem to me that the 50/50 is more accurate as the lines are far closer higher on the scale.
Click to expand...
doing it both ways reinforces it. Actually the dilution test is usually a little less accurate.

If you did the test in full sun you may even be at 50.....
 
Ran a full set of numbers again:

80 F
pH 7.8
FC 12
CC 0
CH 450 brought first noticable color change, two more drops to 500 brought full change, which are we going for?
TA 80 again brought change when the drop went in but none when swirled, 90 to full change
CYA 65, pretty confident on this number, ran twice with same sample

I dropped my estimation to 10,000 gallons, figuring on adding 5.4 oz muriatic to bring pH to 7.6 and not let it get so high. Test FC again tomorrow but probably not have to add bleach till the day after.

I only changed a few hundred gallons so didn't expect CH to drop much at all.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply