2nd test with T-100- need help with "goals"

[lohmaraj]

Here are my readings as of a few minutes ago...

FC 7.0
CC 0.25
TA 90
PH 7.5
CYA ~42
CH-230

Pool is fiberglass, indoor, heated to about 86-88, ~14000 gallons, and very little sunlight.
I was hoping to get some recommendations on goals... right now I was thinking...

FC 5.0
TA 100
PH 7.5
CYA ~40-50
CH- 260

Also, this was the very first time I have seen any indication of CC... one drop of the reagent made the sample clear again. The FC is really high and has been for a while despite the fact that no form of CL has been added in quite a while. Does swimming it it cause some CC creation? How long would it take for CC to disperse after someone actively using the pool? Is this where I might need to get a UV light?

 

[Richard320]

You neglected to list pH. And that is perhaps the most critical for swim comfort. Does the pool have a saltwater generator or something? A puck feeder? The FC is just a little high, but nothing I'd worry about. I wouldn't worry about any of the current readings you posted.

CC is formed when organic compounds react with FC. Meaning: sweat, dead skin, snot, spilled drinks, crumbs, leaves, dirt... So, yes, swimming will generally deplete FC and create CC. If you have a large swimmer load, UV might be helpful. But if it stays below .5 all the time, don't worry. Even those of us with pristine, balanced pools show CC readings.

A target of 5 is probably fine. When FC drifts down below, add some more bleach.

 

[lohmaraj]

I edited my original post... PH is 7.5 which I think is a good goal.

I was using a puck floater and FC was about 2.5 a few weeks ago, before I realized that it should probably be much higher... so I dropped two pucks in, opened the floater and let it run in front of the pump inlet... that was too much... couple of days later it was over 7.0... I thought CYA had shot way up also but it does not look like it has really climbed too much. Using the T-100 CYA test, I go something between 40-50 and much closer to 40. I took the floater out quite a while ago but the pool sees little sunlight this time of year and just recently got some decent use.

Anyone have a way to estimate how much CYA the 3" tablets add to a pool? I have a ton of them left by the previous owner and our pool needs very little FC. I'd like to be able to use them very slowly over time as a FC maintainer possibly along with the use of bleach for more significant changes.

Thanks for the info on the CC... had 3 bodies in the pool for several hours, early this morning. It was the first time I had seen CC and thus it made me nervous.

I have not read all of the "more detailed test directions" so will turn to that.

 

[jcowart]

16000 gal pool calc shows 2.1 CYA per 8 oz so it can get out of hand quick. I would find someone who is still pool stored and try to sell it to them. Also I see you gave a .25 reading. It's good to get a accurate reading but you can use a 10 ml sample for FC and save on testing drops. Just multiply by .5

 

[duraleigh]

Stop using the pucks from here on. An indoor pool will do better with a CYA of around 20ppm.

YOu can drain half your pool to reduce CYA or (and this would be my choice) simply allow your CYA to slowly reduce over time by with the addition of fill water. This may take a very long time (months) in an indoor pool.

Refer to the FC/CYA chart up in Pool School to keep your FC at the proper level while the CYA reduces (your close now).

The rest of your numbers are fine. Pool School gives you guidelines for targets. How does your water look?

 

[UnderWaterVanya]

Re: 2nd test with T-100- need help with "goals"

Here are my readings as of a few minutes ago...

FC 7.0
CC 0.25
TA 90
PH 7.5
CYA ~42
CH-230

Pool is fiberglass, indoor, heated to about 86-88, ~14000 gallons, and very little sunlight.
I was hoping to get some recommendations on goals... right now I was thinking...

FC 5.0
TA 100
PH 7.5
CYA ~40-50

CH- 260



Also, this was the very first time I have seen any indication of CC... one drop of the reagent made the sample clear again. The FC is really high and has been for a while despite the fact that no form of CL has been added in quite a while. Does swimming it it cause some CC creation? How long would it take for CC to disperse after someone actively using the pool? Is this where I might need to get a UV light?

How did you measure CC of 0.25? 10ml sample gives 0.5ppm, 25ml sample gives 0.2ppm, no way (that I know of to get 0.25ppm.

As far as the goals, TA should be OK at 90, is your pH rising, falling, or stable? If stable leave it alone. If rising, let it fall as you adjust pH. If falling, raise it. With pucks it may fall and you may need more TA. However, picks are going to push the CYA through the roof quickly.

Speaking of CYA the level you have is fine, no need to raise it, the indoor pool you have doesn't need tons of CYA.

UV helps break down CC's, if you don't have them don't fret that's a good thing generally. You are keeping FC a little higher than normal for your CYA level but not "too high".

Go to www.poolcalculator.com enter your info and at the bottom you will find a place that allows you to see the impact of adding chemicals. Put the weight of one puck in and you will see how rapidly CYA will climb...

 

[duraleigh]

CYA reduces FC loss due to UV rays from the sun. Since you have no exposure, there is no need to have a CYA of 40ppm. There are some advantages of a CYA level of around 20ppm for an indoor pool.

So, again, I would suggest you stop using the pucks and take some steps to reduce your CYA.....either very slowly through fill water or a partial drain and refill.

 

[lohmaraj]

okay, cool... I will stop using the pucks immediately... as little CL as my pool goes through, bleach will be cheap... maybe I can sell the pucks on craigslist. I probably won't do anything actively to decrease the CYA and just let it come down over time. Maybe I will keep just a couple of pucks to use to increase the CYA in the very distant future versus buying conditioner. I missed that the calculator would let me see how much CYA is added using the pucks... pretty cool. I will aim for a CYA of ~20. What are the advantages of a lower CYA?

I do have some sun exposure but its not a lot as its pretty much full overcast every day this time of year in Seattle. My pool room does have large, south facing, sky lights but we also have a lot of tall trees.

My PH has been surprisingly stable lately as before I was using a lot of MA. I had increased the TA to a level that was probably too high (~150, admittedly, I was "pool stored") so that probably accounts for the stable PH though the TA has dropped pretty quickly... from 150-90 in about 2-3 weeks.

The pool water is crystal clear.

 

[UnderWaterVanya]

Re: 2nd test with T-100- need help with "goals"

Lower CYA helps when you need to shock the pool.

Most windows block some UV's which are what consumes chlorine and helps break down CC's.

Sent via Tapatalk...

 

[lohmaraj]

great info. Thanks