New convert to BBB (questions and confirmations)

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E

ecowolf

0
Jul 21, 2012
74
California Central Coast
PH 7.6
FC 10
CC 0
TA 170???
CH 340
CYA 100

Hello all. This is my first post on the forum, although I have been lurking for a while now.

Due to the previous owners of our house, and partially because of my own ignorance before I found this forum, I have been draining and refilling my pool to correct CYA levels that were at 190. Needless to say, after learning about the CYA problem, I am no longer using dichlor or trichlor and am now converting the the BBB method. After two partial drains and refills, I now have the CYA down to 100. I'm gonna try to manage that for the rest of the summer and then do another partial drain in the fall to bring it down more.

After the drain was when I switched from dichlor to bleach, so only been using the bleach for a couple of days now. Good news is that last night I did an over-night chlorine loss test and my FC levels held perfectly. And, there is no combined chlorine, and the pool is sparkling. So it looks like I've passed those three criteria. I am keeping the FC between 9 and 12 as recommended by the charts here.

Here is my first question though: I checked the FC this morning and it was 10. Then, this evening I checked and it was 8. So, it appears that my daily chlorine loss is 2. So I added 40 oz of liquid chlorine to bring it back to ten. So that is about a third of a gallon. Is this normal? It just seems like so much! At this rate I will be going through two gallons per week. If this is normal, I'm gonna buy some stock in whoever makes this liquid bleach! Our pool is exposed to full sun all day, so maybe it is normal. I just didn't expect to have to use so much every day.

Second question is the TA. It was totally fine, holding at about 125 before I switched to the liquid bleach. Now, in just a couple of days it has jumped to 170??? This just seems really strange. And the PH is fine, and has been holding steady. I checked my test twice. I don't know if this is related, but when I did the test, it is supposed to turn from green to red. Well before turning to red, it became clear, then with one or two more drops it turned red. I had no idea where to call the drops; at the clear change or at the red change. Any thoughts on what is going on with this? Should I be concerned about it?

Thanks for any help and thanks for a great website.
 
You are going to want to run a slightly higher FC level, say 12-14 for the rest of the summer. I really would not want to risk getting algae and having to shock. Shock level is 39 for 100 CYA!!!!!
 
Welcome to TFP!

Sounds like you got a pretty good handle on things. Make sure you keep the FC up to avoid shocking again at that high CYA level. To get the 100ppm, did you do the diluted CYA test?

If there is such a thing as normal for FC loss each day, out would be 2-4ppm per day ... So you sound right in there.

The TA test is done until the last drop did not cause a color change, then that drop does not count ... So it would be after it turned red and did not continue to change.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Thanks all for the fast responses.

Yes, I did the CYA test using the half dilution method.

I raised FC to 12 this evening. But, Vette, I'm confused. You said 12-14 for FC. The chart here says at CYA 100 I just need to be between 7-12. Are you recommending the high levels just as a preventative because the shock levels are so high for this CYA?
 
Re: TA

I have not seen TA rise using bleach. However my first tests were showing higher than expected. There is a potential problem with that test - if you do not wipe off the tip static electricity can build up and cause the drops to get smaller which leads to a falsely high reading. This was my issue.

Re: CL Daily Loss
I lose 3.5 FC a day. Around a 96oz bottle a day - with a lot of swimmers, more.
 
2ppm per day in full sun is very reasonable. Water temperature also plays a big role in chlorine consumption - so the rate of loss may decline significantly as the weather changes.

As to chlorine cost - if you can find a good source of liquid chlorine it's going to be similar in cost to trichlor. As an example for your pool (mine's the same size so I had all these metrics sitting around) here's 12.5% by the case vs. trichlor

1 gallon of 12.5% bleach is about 8ppm for your pool. You can get a 4 gallon case for about $13. So $13/32ppm FC (1 case) is .41 $/ppm

A 35lb bucket of Trichlor is about $90. An 8oz puck is 3.4ppm FC for your pool. So a full bucket is 238ppm. $90/238ppm is .38 $/ppm

Obviously your costs may vary quite a bit from this, but it's a good ball park.
 
Gosh, I made a mistake on my TA. I just realized that I was misunderstanding the whole correction factor for CYA. The TA of 125 that I mentioned the pool was at before the switch to BBB was with a CYA factor included. I didn't realize that you only need to do that when calculating the Saturation Index. Being as my CYA is so high, the factor was pretty significant (40 I think). So if I add that back to the 125, it puts it at 165, which is very close to my current reading without the factor. The TA of 170 in my original post was without the factor. So it looks like my reading of 170 is correct.

So now my question about TA is this: is 170 too high? PH seems very stable so far, so I am thinking don't worry about TA unless PH starts to get wonky?
 
You are correct again.

No need to worry about the TA unless your pH is drifting up faster than you like.

BTW: I think you interpreted Vette correctly that the extra FC would just be a little buffer to avoid the shock process.
 
Hi ecowolf and welcome to TFP! :)
I'm at about 55 CYA and currently using 2-4 ppm chlorine per 24 hrs depending on the sun and swimmers.
I'm keeping mine 5-8ppm chlorine range, which is 1ppm higher that the Chlorine / CYA chart here:
pool-school/chlorine_cya_chart_shock

I do this because of long work hours and here in central FL. we get nasty thunderstorms and flash flooding, this gives me a cushion from all of the Crud that gets in the pool from the neighbors tree, even though it's not over the pool.
Your #'s look good to me for summer usage. :goodjob:

Chuck
 
Yes I feel that in your circumstance, running a slightly higher FC for the rest of the year is well worth it to keep from having to shock.

Sorry for the late response, I'm over here on the Eastern Time Zone :p
 

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Don't worry about TA, it may be that your fill water has high TA like mine does and so it will go up with tap water and down with rain water.

Just manage your pH and do test TA often enough that you know how much acid you need to add to move pH. TA directly controls the relationship of muriatic acid to changing pH levels. If TA is half what it was, you need half the MA to create the pH drop.
 
You've got a good handle on it. I had to maintain a high CYA pool for over a year without the option of draining due to water restrictions. It can be done, just the way you're planning. Your bleach usage sounds normal. You will use a lot of the FAS-DPD reagents, since the color block test is useless at the levels you need to maintain. So when you order refills, order plenty.

My big relief came with winter rains. I put a plastic diverter on a nearby downspout and aimed it into the spa. Each inch of rain we got translated into about 3" in the pool. The water gets dirty, especially the first day of any storm, but I managed to confine that to the spa. By moving the valves to spa only, I could clear it in about 20 minutes, and then go back to normal.
 
I am using numbers for 50 CYA (I'm somewhere between 45 and 50). My minimum is 4ppm. I average around 2ppm loss, but I try to dose up each time to 8 or 9 so that if I need to miss a night adding bleach, I'm not worried about falling below my minimum. I prefer to add bleach daily, but life has a habit of getting in the way sometime. 9 is not close to my shock level, so perfectly fine to swim in - actually, since I add in the evening and we wouldn't be swimming until the next afternoon, it has normally fallen to 6-7 by the time we would be swimming. This also provides me a buffer for anything that might cause a higher FC loss.
 
One thing that I don't think has been pointed out is that the pH test is usually considered inaccurate when the FC>10ppm ... One of the problems with maintaining a high CYA pool.

Just realize that the pH test will read a little higher than it actually is fine you are at a slightly higher FC.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
jblizzle said:
One thing that I don't think has been pointed out is that the pH test is usually considered inaccurate when the FC>10ppm ... One of the problems with maintaining a high CYA pool.

Just realize that the pH test will read a little higher than it actually is fine you are at a slightly higher FC.
Click to expand...

Can you test pH with FC > 10 reliably after using a Chlorine neutralizer?

I ask because I picked up a 5 way kit from Home Depot (can't recall who makes it) and it uses a much larger sample for pH and the colors seems a little more easily identified than my Taylor. The test instructions have you use one drop of a "chlorine neutralizer" before testing pH. I've checked a couple of samples at around 5-6ppm and found that a single drop seems to knock out the Chlorine (no longer measures any with color test). I have no idea yet if this test is valid with > 10ppm after using the neutralizer but I'm planning to try at some point with 1 or more drops of the neutralizer.
 
The neutralizer (sodium thiosulfate) itself affects the pH and the kits that use it have accounted for the one drop. Using more might throw the test off. If you have both kits, it's easy to figure out whether and how much ot affects it.
 
Well, now I'm a bit stumped. I added some more chlorine this morning to bring the FC up to 14. All fine and dandy. Then after about three hours, the PH creeped up from 7.6 to 7.8. I figured it was the extra bleach. I added a little acid to bring it back down to 7.5. Waited another hour or so, and PH and FC are good. But, then I tested my TA and it was at 210! I'm really confused now. Why is the TA climbing like this? I thought it should have gone down since I was bringing the PH down a bit. Granted, it has only been a couple of hours since last acid adjustment; does the TA lag behind the PH maybe?
 
ecowolf said:
Well, now I'm a bit stumped. I added some more chlorine this morning to bring the FC up to 14. A fine and dandy. Then after about three hours, the PH creeped up from 7.6 to 7.8. I figured it was the extra bleach. I added a little acid to bring it back down to 7.5. Waited another hour or so, and PH and FC are good. But, then I tested my TA and it was at 210! I'm really confused now. Why is the TA climbing like this? I thought it should have gone down since I was bringing the PH down a bit. Granted, it has only been a couple of hours since last acid adjustment; does the TA lag behind the PH maybe?
Click to expand...
Don't test or adjust pH while FC is greater than 10. It may not be accurate.
 
Richard: If I need to keep my FC at 12-14 as Vet suggested, how can I ever test anything? I know the real answer is get my CYA down to a normal level. But I can't do that right now. Tomorrow I have to got out of town for a week and I am trying to get the pool manageable for my wife while I'm gone.
 

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