DallasDan

Thank you very much for the suggestions Richard; I haven't tested the water in the past couple of days and have been just swamped with work...this evening I noticed I've got some mustard algae starting on the walls. I'm fairly certain it's not pollen as it starts on the shady side of the pools and is nearly exclusively on the walls. I'm going to take the water into a new place and see where they place the CYA levels at. If they are high as I've indicated I think I'm going to have a company drain and refill the pool--after reading another of your articles, I'm considering an offline liquid chlorine feeder... Anyway, economy is certainly key here, but I just can't backwash the thing every week or so (to drain water) and dilute it over time. I'll let you know how it turns out. Thanks again for your response--I very much appreciate it. -Dan

Greetings! I am a first time pool owner and recently purchased a home with a pool (about 2 months ago). I have read quite a bit online and several books on pool chemistry and maintenance and would say that I'm a bit overwhelmed by this 25,000 gallon chemistry experiment going on in my back yard! OK this is a long question that hopefully will give enough background for someone to chime in on a recommended course of action. Sorry in advance for my verbosity! I have a 25k gal IG/gunnite pool with white plaster walls. When I moved in the previous owner had let the sanitizer drop relatively low (1ppm); it appears she was maintaining the FC levels solely through the use of an offline tri-chlor feeder. She had exactly (3) 3" Tri-Chlor tabs left and 0 Cal-Hypo when I moved in. Having very little information about the pool I purchased a Taylor Service Complete kit to see what I could measure (being somewhat less than impressed with Leslie's in store testing methods). The previous owner had a company that was somewhat infrequently maintaining the pool, I was able to get this company to come out and take apart/clean the DE filter and at the same time I picked the guys brain that had maintained this pool for the past 12 years. He couldn't remember the last time the pool had been drained. I have noticed that after shocking the pool that the FC levels take literally days to drop down substantially. I have all but shutoff the offline Tri-Chlor feeder and have been testing the FC and CC levels daily. I shocked the pool (Cal-Hypo) Wednesday morning, 24 hours later I had the water tested by the pool company (took the sample in) and it tested 6.5PPM FC (no CC). I had a party yesterday 3-days after shocking with about 12 people in the pool. Today (4-days after shocking) it tests at 4PPM. It seems that Wednesday-Sunday with only a 2.5PPM drop in FC after a pool party and 100ºF days is just not right. I suspect is there may be a HUGE amount of CYA in the pool. I've had some problems with algae (mustard and black) that have been kept under control with brushing (OK a little more effort was required for the black algae!). Phosphate levels are somewhere between 500-1000PPB which I wouldn't think is ridiculously high. What I can't get a solid reading on is CYA. I have a turbidity test that after 50% dilution with tap water places the CYA level at about 200PPM (it's the Taylor test that max's out at 100PPM). The pool company is reading it at about 70. I have been skeptical that my test could be that far off so I took the sample in to watch them test it...I noticed they used a strip that tested 140PPM CYA and the girl said that was inaccurate...she performed a turbidity test and came up with 70PPM. There is a world of difference between 70PPM and 200PPM. Again, I don't know how long it has been since the pool was drained, and I suspect the former owner maintained the FC exclusively with Tri-Chlor. I'm not sure which reading to trust. 70PPM isn't low but I don't think it warrants draining the pool at this moment in time...water and startup chemicals ain't cheap, plus the cost of getting a pump in there to drain the pool. That being said I don't want to dump more chemicals into a backyard chemistry experiment that has gone awry. What has precipitated (literally and figuratively) this question is really the CYA correction for TA is putting my TA way too low. Uncorrected TA measures at around 120PPM (my testing AND the pool folks all agree on this much). If my CYA levels are really at 70PPM the adjustment should place my corrected TA at 99PPM (pH is 7.4). But if they are as out of control as my testing suggests then that might explain some of the scaling around the tile line of the pool and also why the sanitizer levels are taking so long to drop...maybe also some of the algae problems??? --if the FC is "locked-up" in CYA? Before anyone asks, my reagents were new this year, and the other tests agree with both Leslie's and the pool company's measured levels. I wouldn't be maintaining my own pool if it weren't the cost factor--home ownership has proved to have a LOT of unexpected expenses at every turn. I'm trying to do what I can by myself. Any suggestions for getting a more accurate CYA testing performed? Or suggestions in general?? Thanks for reading--I know it was a novella!