CYA level and chlorine level and pool store recomendation

[Fishcrazy]

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]

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]

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]

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]

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]

It is certainly fine to run the pump with your cover on. Won't hurt a thing. I do it all the time.

[Fishcrazy]

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?