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View Full Version : CYA level and chlorine level and pool store recomendation



Fishcrazy
08-07-2011, 08:32 AM
Hi and thanks for a great forum. I sure am lucky to have found it as I am a new pool owner and knew nothing at all about pools and water chemistry before now and what I do know came from this forum. I have a 27 foot round above ground. My latest water test from the pool store is as follows. TC 2, FC 2, pH 7.2, TA 120, CH 200, CYA 60. The pool store has sold me a lot of supplies and they of coarse recommend treatments which I have initially followed due to lack of any knowledge to the contrary on my part. So here is what they have had me do so far. I initially shocked the pool with some granular product and added algecide and stabslizer. They wanted me to add 12 pounds of stabilizer to the pool an I decided to add only half of that to see what it produced after it got in the water. A CYA of 60 is what we got. Now at that level they are recommending that I keep the FC at 2. I have been using the pucks they sold me to chlorinate with and I know that that adds stabilizer to the pool as well. I would expect the level of CYA to rise going forward using these pucks and therefore requiring more chlorine with these higher CYA levels. At current CYA levels I should be at higher FC level than I am now according to the BEST GUESS chart. My delima is that the pool store product doesnt recommend on their lable that swimmers use the pool above a FC of 2. But htey recommend that you bring the level up to 5 after a rain or lots of use in the overnight period to give the pool a chance to return to the 2 level before swimmers reenter the pool the following day. So my question is obviously about what is the chlorine level I should be maintaining? Best Guess has me at 5 and the pool puck bucket says dont swim in water over 2. I dont understand why the requirement for FC rises with higher CYA levels. Do I really need FC of 5 and is that ok to swim in? I am new to all of this and dont want to harm anyone with too much FC in the pool. And what is an ideal level of CYA to strive for? Or is that more of a take what you get kind of thing and you adjust your chlorine accordingly? Thanks for any insights you may have for me. If I continue to use up the pucks before I switch to bleach will I be damaging my water situation with to much CYA? Recommendations? Thanks in advance!

aylad
08-07-2011, 01:33 PM
Hello, and welcome!!

Looks like you've been doing your homework and have a pretty good handle on things in your pool. I'm glad that you only added 1/2 the stabilizer that the pool store suggested...most folks keep their CYA levels at 30-50 ppm, so you're not too far on the high side. You are right, though, in the understanding that you DO need to keep higher chlorine levels with higher CYA levels. This page http://poolsolutions.com/gd/best-guess-swimming-pool-chlorine-chart.html can shed some light on the reason why the chlorine levels have to be elevated, along with a link to the chart for reference. As far as the recommended level--well, that's up to you. Most folks find that 30-50 works well for them. But for those in very hot climates, with excessive chlorine consumption that is NOT due to algae or other stuff being oxidized in the water, we recommend that they bump it up a little, maybe to the 50-60 range. I personally keep mine a lot higher than that--80-90 ppm, but my pool seems to be the exception to the norm. My pool is in full sun all day, no shade, hot and humid Louisiana temps, with large kid/dog bather load. If I try to keep my CYA as low as most people, I couldn't afford the chlorine!! With my CYA as high as it is, though, I only have to add one large jug of bleach every other day to maintain my 8-9 ppm of chlorine.

With a CYA of 60, you must keep your chlorine levels between 5-10 ppm at all times. NO lower than 5, or you're asking for an algae bloom and unsanitary water. I know the pool store says no more than 2 ppm chlorine, but that's with 0 CYA, and it's even low for no stabilizer. I don't know how to state it so that it makes sense (the link I gave you above should help you understand it, though), but swimming in a pool with 5-6 ppm of chlorine with CYA at 60, is no different than swimming at a pool with 1-2 ppm chlorine at CYA of zero. With my high CYA and higher chlorine levels, no one ever has any problems--no burning eyes, no faded suits, no other complaints.

If you want to keep using the pucks, you can--but be aware that for every 10 ppm chlorine that gets added, you are also adding 6 ppm of CYA, and you must adjust your chlorine accordingly. You can close the pail of pucks and store them in a dry, cool area, and they will still be good for next year, if you wanted to do that.

One thing I think you should consider is whether or not you plan to close/winterize your pool this year. One of the huge disadvantages to high CYA levels is the amount of ammonia that it can be converted to over the wintertime while the chlorine levels are not being sustained. Some pools experience this, some don't--but in the ones that do, over the winter bacteria converts the CYA to byproducts, including ammonia. This results in opening a pool with 0 CYA but a HUGE chlorine demand, which is hard to overcome but must be overcome in order to get your pool chemistry where it needs to be. This is not a problem for me because my pool stays open all year--but if you plan to winterize your pool, I would not run the CYA up any higher than it has to be. Then again, it's your pool, your choice.

Hope this helps!!

Watermom
08-07-2011, 01:35 PM
Hi and welcome to the Pool Forum! Sounds like you have been doing quite a bit of reading here on the forum. Good for you!

You need to keep your chlorine at the levels recommended in the Best Guess chart. If you have a CYA of 60 and run chlorine levels at 2ppm, you WILL end up with algae. I would suggest not using the pucks since they will add more and more stabilizer and you are fine at 60. However, if you choose to go ahead and use up the pucks, you'll have to run higher and higher chlorine levels per the Best Guess chart. (I wouldn't add the rest of the stabilizer.) We typically recommend a CYA level between 40-50 for most pools and you are already a little past that, but still ok at 60. Keep your chlorine levels per the Best Guess table all the time and you will not have any algae problems. Also, it will NOT harm swimmers.

EDIT --- Looks like Jan and I were posting at about the same time, but the advice is pretty much the same.

HA! Beat you this time :) :) Jan

Fishcrazy
08-08-2011, 08:55 AM
I appreciate the help. I have been using test strips to get some readings when I could not get to the pool store but I have come to think that I need my own test kit to stay on top of this. First off I am not so sure of these test strips and their precision and secondly Im not so sure of the pool store's precision either! Case in point. My strips would not test for CYA and the pool store test result of 60 is not the same as my recently acquired test kit result of CYA = 35. I ran the test twice to make sure that it was right. I look down through the top of the tube at the dot till it totally disappears? Or can you look at the dot through the side of the tube? I read it from the top. Is this black dot test the same one that comes in the kit? Im going to test it again to see if it is correct.

My pool is situated under some shade trees and only gets direct sun around noon for a couple of hours. I do have to keep after the leaves constantly because of this. Every day the skimmer will be full practacly to the point of cloging up the circulation system and then again during the day. I suppose that I will need to cover the pool if I have to leave for any period of time for fear that the leaves will choke off the circulation all together. Any suggestions would be welcome on this problem.

My pool seems to hold its chlorine well. I put a couple of pucks in the other day and the FC level went up to 5 ppm. It seems that when I have added chlorine in the past the level maintains itself for a week. It surprised me to see the FC up to 5 from the two pucks but I guess Im getting to a level of chlorine that is telling me that I need to test more frequently to figure out what level of addition I need to make in chlorine on a regular schedule to maintain the required amount of chlorine. The strange thing about the Best Guess table to me is that there is a higher level of FC required with a higher level of stabilizer. Im sure I dont understand the chemistry but it seems intuitive that if you add stabalizer to make the chlorine more effective then why does more stabalizer cause one to require more FC? I would think that more would require a lesser FC due to the stabilizer effect of protecting the chlorine from being burned off by the sun. Im not thinking about this right, am I?

Im off to check the CYA again and the test strip method for the other readings. Can you recommend a test kit that would complement the one I have or do I just have to end up with 2 CYA tests? Thanks for all the help!

aylad
08-08-2011, 09:09 AM
You are right to question the accuracy of the test strips...around here we call them "guess strips" and don't rely on them at all, because they are neither accurate or precise. They are good for telling you if there IS chlorine or if there ISN'T chlorine (sometimes), but don't depend on them for regular maintenance testing.

Sounds like you're doing the CYA test correctly--you view the tube from the top, holding it at waist level, and put the solution (reagent mixed with pool water, shaken VERY well) in until you can't see the black dot. It doesn't surprise me that your test result is different from the pool store--and I would go with yours.

The test kit that we normally recommend is the K-2006, which can be found at the Amazon link in my sig (anything that is purchased through this link results in a small donation to PoolForum, too). If you already have a kit that uses drops to test for pH, TA, CH, and the reagent test for CYA, then you can just add the K-1515 at the same page, which is just the chlorine test that uses powder and a drop system, and is capable of measuring accurately up to 50 ppm, as well as measuring CC.

I'll let the chemists explain why the chlorine levels need to be higher with the CYA being higher, but the bottom line is that as your CYA rises, so must your baseline chlorine. And yes, you do need to test chlorine at least daily to make sure that you're maintaining the required level to keep the pool from going green on you. Remember that the pucks are adding stabilizer, so if you continue to use those, you'll need to test for CYA occasionally, too. Not everyday, but I would say at least weekly or so if you're using the pucks on a regular basis.

Janet

Fishcrazy
08-08-2011, 09:11 AM
Just tested water. CYA 35, FC 5, Alk 40, pH 7.2, TH 50.

Alk seems low. Should I do something there and if so what? TH also seems low but what do I need to do for that. These test strip readings are quite different from the pool store readings on 8/5/11. Would readings for Alk go from 120 to 40 and Calcium hardness go from 200 to my TH of 50 in 3 days ? I suppose CH and TH are not the same thing?

The CYA I believe to be correct according to the black dot test. Wonder why their reading was so much higher at 60 3 days ago. Only thing I have done is add 2 pucks chlorine. It did rain 2 to 3 inches since their test but that is the only other input to the pool except the very high heat of 100 deg each day.

Watermom
08-08-2011, 10:38 AM
You can add a little baking soda to raise your alk. I'd add a couple pounds at a time slowly to the skimmer while the pump is running. After a couple hours, retest and redose until you get it somewhere between 80-125. Your pH is ok at 7.2 but you don't want it lower. We use 20 Mule Team Borax (laundry aisle at Walmart) to raise pH. You add it in the same way as the baking soda. Actually, you can add them one right after the other. I'd start with a half a box and see what that does for you. You want pH somewhere between 7.2-7.8. I usually keep mine around 7.4-7.6.

If you are going to use the trichlor pucks, you'll need to keep an eye on your pH and your CYA. They are stabilized which means they add CYA. If yours is already at 35, you can use the pucks for awhile, but when your CYA gets to around 50, you'll want to quit using them and only use bleach. You don't want your CYA too high. The trichlor pucks are also quite acidic and will push your pH down.

As far as calcium hardness is concerned, vinyl pools don't need calcium so don't worry about it.

Like Jan said, do yourself a favor and get a good kit. Test your chlorine daily, pH a couple times per week (unless you are tweaking it), alk every couple of weeks (again, unless you are tweaking it), CYA every couple of weeks until you hit 50 and then your CYA should stay pretty stable for the rest of the summer.

Hope this helps!

CarlD
08-08-2011, 11:24 AM
OK, I'm going to take my stab at it: I think you should not use the tabs at all. They lower pH, and yours is low, and they raise CYA, and yours is a bit high. Stick with regular unscented bleach. 1 gallon of 6% raises 10,000 gallons of water 6ppm of FC, so figure accordingly. Save them for next year when CYA is low.

With both a low Alk and pH, another alternative is Arm&Hammer Washing Soda, in the yellow box. It will raise both and at $.80/lb, is far cheaper than the pool stores sell it for, though it's the same stuff (sodium carbonate) as their "pH Up!" and similar products.

But baking soda and Borax will work just as well.

Carl

aylad
08-08-2011, 01:06 PM
Personally, I wouldn't adjust the levels in the pool based on test strip results. When you spoke about the "newly acquired kit" in your above post, was that just for CYA? Or do you have drop-based testing for evrything else too? If you're depending on the strips, I would not dose the pool based on those results. You'd do better to go with pool store results if they're using drops.

In the post above where I spoke of test kits, if you don't have drop-based testing for TA, CH, pH, Cl, etc...then the K-2006 is the one we recommend. I was under the assumption that the "newly acquired test kit" was drop-based for everything else but chlorine. In that case, then the K-1515 is what you want.

Janet

Fishcrazy
08-08-2011, 02:58 PM
Janet Sorry for the confusion and I think I will take your advice and wait for the kit to arrive. I have been using test strips for my personal testing except that I did just get a CYA test kit because the test strips did not have that test included and I therefore had no way to check it other than the pool store. The results I get with the test strips are quite different from the pool store results which im sure are good quality tests. I therefore am not going to act on the test strip results and am going to get a test kit to do my own testing with. I am suspect of the pool store test results as well due to our difference in the CYA results that we show. I will post the test results as soon as I get the kit.

Carl thanks for the input. I will get some washing soda if the test numbers reveal that they are the same as posted above with a real kit. Im only confidant of the CYA number though at this point. I was relieved that my CYA tested at 35 as opposed to the 60 that the pool store told me that it was. Im somewhat surprised to hear that you feel 35 is high for CYA. What would your target level be for CYA?

aylad
08-08-2011, 03:48 PM
I believe that Carl was referring to the reported CYA at 60 ppm as high--we generally recommend that people start out around 40 ppm in their pools, and only raise it from there if there is a continuing problem with chlorine consumption that is due to the sun, all other causes ruled out.

Janet

CarlD
08-08-2011, 03:56 PM
Thanks, Janet. Yes I was referring to CYA=60 as high. It's not bad, you simply must compensate for it.

Carl

Fishcrazy
08-09-2011, 12:56 PM
Well I recieved my test kit today and ran the following test on the pool. FC=7.5, CC=0.5, pH=6.8, TA=40.

I did not recheck the CYA and assume it to be unchanged from 35 yesterday. pH is low and Alkalinity low. Washing soda? How much? My pool is 27 round 52 inch. I have initally added algecide to the water and am wondering if I should do a periodic maintenance dose of that. If so how much and how often? Thanks

CarlD
08-09-2011, 02:19 PM
Hi Fish:
1) I would add a box of washing soda, with the filter running, wait an hour, then check pH again. Your pool MAY be 6.8, but it may lower and you won't know until it's 6.9 or better. If it's still below 6.8, put in a second box. wait an hour, and test. At this point I would switch to borax instead of washing soda..your TA should be fine by then.
2) DO NOT USE THE ALGaECIDE! It will only make more problems. The ONLY algaecide we ever suggest using is called Polyquat 60%. If it says "Poly....<something unpronounceable>.... 60%" and has no other active ingredient, that's the stuff. All other algaecides cause more trouble than they are worth. If you use PolyQuat, only use about 1-2 ounces a week--that's all
3) CC=.5 means .5 or less. It should be no problem, especially if your chlorine doesn't drop much overnight. If it does, raise the chlorine up to FC=15 and it should clear it.

Carl

Fishcrazy
08-10-2011, 06:36 AM
Thanks a lot Carl. I will get that started today. I sure appreciate all the advice!

Fishcrazy
08-15-2011, 09:24 AM
I have been testing regular and until yesterday saw no need to add chlorine. I have been watching the FC fall from 6 at about a point a day till it hit 2.5 and decided to add some stabilized tabs through the floating chlorinator. My purpose here is to figure out how to set the chlorinator to keep the pool chlorinated at a steady level for purposes of extended times away from home. My CYA is at 35 so I can afford to use some of the stabilized tabs and I am watching the levels for any signs of increased levels. As soon as I figure out the settings for the chlorinator Im switching to bleach. Im hoping to be able to cover the pool while I am away with the pump running and the floating chlorinator loaded to keep the pool going for a couple of weeks. Am I just barking at the moon with this plan or what? I just have to be away sometimes. If this is not possible ahen any suggestions would be greatly appreciated. My alk=50 and the pH seems stable at 7.2 and CL=3 up from 2.5 over 2 days of the floating chlorinator at work. I have very little sun on the pool during the day. About 2 hours is all. My CL drops about a point a day it seems with CC=.5 or less. I only get a hint of pink with one drop clearing it. Does anyone make pucks without stabilizer in them? I dont know what I will do if CYA gets too high to use the pucks when Im away. Is there any reason that I should be concerned about the CC=0.5? It seems to be slowly disapating but traces still there. Any thoughts about covering up for 2 weeks at the time while running the pump would be appreciated.

aylad
08-15-2011, 11:22 AM
There are pucks without stabilizer in them, but they are cal-hypo and are NOT going to work for what you want. They used to make a good one that was encased in plastic like a medicine capsule, and they worked great, but for some reason they did away with them and the ones they have now just go to mush after a day or so. Won't last long enough for you to do what you want to do.

Keeping the tabs in the chlorinator while you're away, but using bleach while you're at home, is a reasonable plan. Just make sure the floater is tethered so that it can't float over near the pool edge and park itself there--you'll end up with bleached liner from concentrated low pH and high chlorine. I would also consider raising your pH just a bit before you go, just to make sure it doesn't drift below 7.0 while you're gone. If the CYA gets too high, then you can either backwash/refill some of the water to lower it, or just up your chlorine levels to compensate. If you're only using them occasionally, though, I don't think you'll have a problem. The other option would be to add a dose of Polyquat 60, give it a day or so on recirculate, then shock the pool and cover it up--that's what many folks around here do when they're closing for the winter. The worst case is that you may have a little algae when you come back, but that's easily dealt with. My concern would be leaving the pump running for two weeks with no one to check and make sure the skimmer isn't plugged up with something, the water level isn't too low, etc....

Janet

Fishcrazy
08-15-2011, 12:24 PM
Thanks for those thoughts Janet. I am planning to cover the pool but leave the pump on when I leave it for any extended time due to the fact that the leaves and pine needles WILL clog the skimmer for sure. Is there any reason I am missing in this thought process to disuade me from doing this? I know that if I developed a slow leak that droped the water down below the skimmer I would be hosed. Maybe a low water switch to cut the pump off in that case? Any ideas out there on the switch?

Maybe I should just do what you suggest with the polyquat 60 and raise the Cl to shock level and shut it down for the time Im away. The other possibility is the neighbor could look after it. I have not approached him about it but they would enjoy having a pool for a couple of weeks Im sure. Just dont know if I should impose on him so much.

Oh well. Any of you that have similar issues I would sure like to hear from you.

chem geek
08-15-2011, 03:40 PM
When we go away for more than just a few days we usually have someone stay in our house and we have them add chlorine to the pool. With our mostly opaque electric safety cover, they only need to add chlorine about twice a week.

If we didn't have that option or a neighbor to help, we'd just use Trichlor pucks in a floating feeder. For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm. So for a week, that's not too much CYA. The Trichlor pucks won't last for much more than a week anyway. If you go on vacation for more than one week, you pretty much have to have someone look after the pool. Those with automatic dosing systems such as The Liquidator or peristaltic pump or saltwater chlorine generator (SWCG) can sometimes go for at least a couple of weeks depending on capacity and whether they use a pool cover.

Fishcrazy
08-16-2011, 09:04 AM
Thanks for the info chem geek. This floating feeder Im using is the cheapest thing I have bought for the pool so far. I wonder id there are better ones than this floating turtle or are they all this cheap. Anyhow in one day and a half the Cl level has increased 0.5 ppm. I have the floater set for a 10,000 gal pool and I hav e a 18,000 gal pool. I dont know how much control this adjustable floating dispenser will afford me but if Cl continues to rise at this rate I may have to do something different. Maybe it will not continue to rise but will reach an equilibrium at some acceptable point. We shall see in time. I plan to check the Cl levels daily.

I have read about The Liquidator and think that it may be a good solution. I however have not found a source to purchase one online or otherwise. Could you provide a link for the unit? Thanks so much for your help!

chem geek
08-16-2011, 11:53 AM
If the pool is exposed to any sunlight, then the chlorine will reach an equilibrium rather quickly since the amount of chlorine added by the Trichlor is fixed but the amount of chlorine lost from sunlight is proportional to the FC level (for a given CYA level).

As for The Liquidator, you can buy it with the very much needed upgrade kit at PST Pool Supplies (http://pstpoolsupplies.com/hasa-pool-the-liquidator-updated.aspx).

Fishcrazy
08-17-2011, 10:12 AM
Well the last two days ahve FC =3.5 and seems to be holding there. I have the floater diled down to a 10000 gal pool size in this 18000 gal pool. The pucks seem to be lasting quite a while at this setting. Be interesting to see how long three of them will last in my pool. Do they suddenly get soft and dissolve faster or are they consistant till they are completely gone? Wondering if these last a week say if I could expect to be able to just go to 6 tabs for a two week period? My pH seems to be steady at 7.2 and I have not tried to raise it any. If I did raise the PH would that change anything with the amount of chlorine that I am using?

On another note I am about to install a timer for the pool pump. I have been running the pool filter 24/7 but dont feel that this is necessary. Any suggestions for a scheule for a 27 round 52 inch pool. I was thinking about 16 hours a day. Thanks in advance for any and all advice.

chem geek
08-17-2011, 11:31 AM
Trichlor tabs dissolve fairly slowly and fairly evenly. They usually don't fall apart. The rate of dissolving will slow down somewhat when they get much smaller since that rate is roughly proportional to the surface area. The pH should be dropping given your fairly low TA of 50 that you last reported. Is the pool covered or uncovered? If you were to add 10 ppm FC to the pool using Trichlor and that chlorine was used/consumed at about the same rate it was being added, then the pH would drop from 7.2 to as low as 6.8 except for carbon dioxide outgassing. So normally you have the pH start out higher when using Trichlor and usually have the TA higher as well. Even if you started with a pH of 7.7, with the low TA the pH after 10 ppm FC would end up at around 7.0 if there were no outgassing.

As for pump run times, you usually figure on one turnover per day but can adjust to keep the water clear. The right amount depends on your circulation. If it's really good, you can sometimes go shorter; if not, then longer; but one turnover per day is pretty typical. Note that an above-ground pool often has terrible bottom circulation since there aren't usually many returns and there isn't a floor drain. Pointing a return diagonally downwards sometimes helps with circulation.

Fishcrazy
08-17-2011, 02:05 PM
I have not run anything but the Cl test and pH since I started these Trichlor tabs on Sunday when my FC was 2.5. I dont have the pool covered but the tree canopy over the pool is considerable affording no more than 2 hours of direct sunlight per day. I guess I need to figure what the flow rate of this 1 1/2 horse Hayward is to determine the turnover time. Thanks for the tip on the circulation of the bottom water.

If Im hearing you right I need to get the TA up some more and prior to leaving the pool for the two week trip I need to make sure that the Cl is either up high around 7 or more and the pH is elevated abnormally high? I have only been feeding trichlor for 3 days and pH seems to be holding steady at 7.2. We will see what happens with tomorrow morning's water test. I think I will test the CYA abd TA also tomorrow. What would I be looking to get the TA up to? Thanks for the help again.

chem geek
08-18-2011, 01:01 AM
Your few hours of sunlight explains some of what is going on -- namely that your chlorine usage is probably low. If I figure that it is only 1 ppm FC per day, then in one day the pH would only drop from 7.2 to 7.15 so not be noticeable and that assumes no carbon dioxide outgassing. If you are going to be gone for a week so we figure 7 ppm FC, then the Trichlor will lower the TA by around 5 ppm so I would just raise your TA by 10 ppm to 60 ppm and your pH to 7.7 before you leave. That will have the pH drop to no lower than 7.2 after a week, assuming the 1 ppm FC per day assumption is correct. That seems reasonable. You don't have to raise your TA way up because you'll probably be frustrated lowering it again for pH stability when you return (I assume you have the TA very low for pH stability when using bleach or chlorinating liquid -- if not, then raising it to 80 ppm would be OK).

Fishcrazy
08-18-2011, 12:38 PM
Today the water test surprised me a bit. pH=7.0, FC=3.5, CC=.5 or less, TA=40, CYA= 30. Surprised to see the CYA down a bit especially since adding trichlor. But it is what it is. I am going to raise the pH to around 7.4 to 7.5 and the TA to around 60 and see what happens from there. I am beginning to think I will not be able to make it two weeks at the time away without some intervention by someone to add some chemicals to bring the pH up or maybe I could raise the pH to say 8 when I left and expect the decrease of 0.05 per day to bring me to pH = 7.3. Would there be any danger in taking the pH to 8 right before I leave? TA seems to be falling rather briskly. Looking like a raise to 80 would be a good Idea prior to taking off. Maybe higher? I am not intentionally keeping TA down as I did not know that a low TA would promote pH stability when using bleach. I was under the impression that my TA needed to be raised from my initial levels to promote stability in pH. Glad I got that straight. What would be a good TA level when using bleach? Thanks chem geek! I really appreciate the insights you are providing.

chem geek
08-18-2011, 03:09 PM
The CYA test is hard to read accurately so variation of 10 or 15 ppm is not unusual and doesn't mean it actually dropped. Going two weeks without any maintenance on the pool is a big stretch. At least with your low chlorine demand you could probably load up enough Trichlor pucks/tabs to last long enough assuming you turn down the feeder slats appropriately. Yes, you could raise your TA level which will help keep the pH up in spite of the Trichlor assuming the pool remains uncovered. Over two weeks, with 80 ppm TA and starting with a pH of 7.8 (I wouldn't go to 8.0 as you might get some metal staining if you have some metal ions in the water) you would end up as low as 7.05 in pH though in practice it will likely be higher due to carbon dioxide outgassing -- a guess would be 7.2. So that might be OK. A TA of 100 ppm would end up no lower than 7.1 in pH (this all assumes 1 ppm FC per day added from the Trichlor and consumed/used). So you can probably raise the TA to the 80-100 ppm range, load up the Trichlor tabs, and be OK, but if the feeder is set too high then you might run out while if it is set too low then the chlorine level could get too low. It's dicey and tricky to get right which is why automated systems and especially helpful neighbors work out better.

If you were always going to use Trichlor, then your TA could be at 120 ppm or even higher, but there's not much sense in getting it that high if you are going back to chlorinating liquid or bleach upon your return.

Fishcrazy
08-19-2011, 11:12 AM
I figure I may have to call in someone to check on the pool. I dont feel like I should impose on the neighbors this much though. And if they dont know squat about pool water then they probably will be somewhat reluctant to take on this responsability.I just dont know if it is too much to ask.

Keeping the pool covered is going to be mandatory as the leaves would surely clog the skimmer up in short order. That is unless I enlist the neighbor's services. I sometimes clean the leaves from the skimmer 3 times daily.

Im not yet defeated on this working but it sure seems like a lot of ifs here on my situation. I appreciate all the advice chem geek! I have not done any water testing today yet. Will get to that though soon.

aylad
08-19-2011, 04:11 PM
checking on the pool and adding a little bleach shouldn't be too much of an imposition on the neighbor--it actually sounds more time consuming than it is. If you'll leave a checklist of what they're supposed to do, and what/when they're supposed to do it, it really shouldn't be a huge job.....and worst case scenario, if there' s a little green when you get back, we can help you deal with that too!!

Janet

Fishcrazy
08-20-2011, 07:37 AM
Thanks Janet. It is nice to have some good info available from all of you here at this forum. You all have been a big help. trying to get the pH up a bit now but used my last bit of Borax and that didnt do a lot but did get me back to 7.2. I want to take it to 7.5 for now and see how the trichlor holds up. I have had three tabs in the floater for 7 days through the end of today and they are over half disolved. I suppose that if I had 6 tabs in there they would alll be about the same amount dissolved as the three I am experimenting with now. My thought is if I did hav six tabs then my FC would probably be 5.5 probably instead of the 4 that it tested yesterday on only the three tabs judging by the fact that since last sunday when I started the three tabs the FC was 2.5 and now is 4.0. I dont know if that is the right way to think about it though. The only thing I have changed is the pH during the test period. I am probably going to push the TA up along with the pH some more today and continue to watch the tabs to see how long they last and monitor the FC level. Be curious to see how much longer these three tabs last.

One thing I am doing different than I would have to do when I leave is now I dont have the pool covered. Im assuming that there would be no reason that I could not cover the pool while running the pump. I do have a leaf problem that I must deal with using the cover. Since I would only be blocking the 2 hours of direct sun I get on the pool daily I would think the net effect would be a slightly higher FC count. Anyone know of a reason I should not cover the pool while running the pump please let me know.

If these tabs dont make it through the next week then Im thinking I may consider starting out with a much higher FC level to carry me through the second week that Im away. My pool only seems to eat FC at agout 1ppm per day so that may just work. All things being the same if I had started with FC at say 6 instead of 2.5 as I did last Sunday then now I should have a FC of 7.5 with tabs still remaining in the floater. I may have to start awith FC a bit higher than than 6 depending on the time that these tabs last but this could work.

Watermom
08-20-2011, 12:54 PM
It is certainly fine to run the pump with your cover on. Won't hurt a thing. I do it all the time.

Fishcrazy
08-21-2011, 10:25 AM
Thanks Watermom! My test today revealed the ph has gone up tp 7.5 and the 3 tabs seem to se still raising the FC level now to 4.5 and no CC at all. Is it characteristic for the trichlor pucks to continue to dissolve at the same rate until they are gone or do they speed up at the end?