Hi all - I need some help with the SLAM process. Iíve been going through dozens of gallons of 10% chlorine to maintain the pool at SLAM levels over the past week and although there has been marked improvement in the appearance of the pool, the chlorine continues to be consumed at a very brisk rate and doesnít show any sign of slowing down.
Some background - My wife and I recently moved to upstate New York and bought a house with a pool (pool details in signature). Neither of us have ever owned a pool before. Before we moved in I read extensively about pools on this site. Thank you for all of the wonderful information!
The pool we inherited didnít seem to be in very good condition. Although it was only mildly greenish (and very cloudy), brushing the side kicked up abundant half-dead algae and debris and the cartridge filter was caked with the same stuff. Ran some preliminary tests (using the TF100 test kit), cleaned the filter, and starting following the SLAM procedure. Over the next couple of days the greenish color disappeared and then the pool slowly started to clear. For the past couple of days it has been almost entirely clear and looks ready to swim in.
The problem is that the FC is still dropping very quickly (both during the day and night) and Iím still using 8 to 10 gallons of 10% bleach every day just to keep it at SLAM chlorine levels. Itís losing 10-12 ppm just overnight (so it is nowhere near passing the OCLT) and this rate of chlorine consumption doesnít seem to be tapering at all. Iím beginning to worry that I may be overlooking something or doing something wrong. Itís also getting expensive and time-consuming. Iím including below all of my test results (which are mainly FC) and my actions in response to results. Iím also including a few pictures of the pool. I put a dark hose into the deep end (8 feet at the deepest) for the pictures just to demonstrate how clear the pool is. I also have a heater, but I havenít turned it on during the process.
DATE TIME pH Chlorine (FAS) Action 6/10 AM 6.8 1.5 ADDED 6 GALLONS 12.5% 6/11 AM 1 ADDED 6 GALLONS 12.5% 6/12 6:00 AM 7.2 13 ADDED 5 GALLONS 10% 6/12 10:40 AM 24 6/13 7:00 AM 7.2 5 ADDED 5 GALLONS 10% 6/13 2:00 PM 20 6/13 8:30 PM 12.5 6/14 5:30 AM 7.2 2 ADDED 5 GALLONS 10% AND 5 BAGS SOLID SHOCK 10:30 AM 30 4:30 PM 16.5 ADDED 6 GALLONS 10% 6:45 PM 32 6/15 6:00 AM 16 ADDED 2 GALLONS 10% 10:00 AM 21 12:00 PM 19 ADDED 2 GALLONS 10% 4:00 PM 21 ADDED 3 GALLONS 10% 7:00 PM 28.5 6/16 5:00 AM 14 ADDED 2 GALLONS 10% 11:00:00 AM 17 ADDED 2 GALLONS 10% 2:00 PM 18 ADDED 2 GALLONS 10% 4:00 PM 23.5 ADDED 3 GALLONS 10% 7:50 PM 25 6/17 6:00 AM 15.5 ADDED 3 GALLONS 10% 9:00 AM 21.5 ADDED 3 GALLONS 10% 12:15 PM ADDED 1 GALLON 10% 1:00 PM 25.5 3:50:00 PM 18.5 ADDED 4 GALLONS 10% 8:00 PM 25 ADDED 4 GALLONS 10% 6/18 6:00 AM 25.5 ADDED 4 GALLONS 10% 10:45 AM 30.5 ADDED 2 GALLONS 10% 3:45 PM 23.5 ADDED 5 GALLONS 10%
CYA ACTION 6/10 <20 ADDED 120 OZ CYA 6/12 40-45 6/14 40-45 6/18 40-45
TA CH 6/10 75 325 6/11 70 6/12 310 375
Other notes - The pool has two skimmers, two main drains, and four returns. Three of the returns are in the shallow end, around the stairs. One return is at the deep end. They all have a forceful flow. Iíve been brushing the sides and floor as aggressively as I can and vacuumed a few times as well. Iíve used a small brush to try and get in the crevice behind the main drains and beneath the ladder. Iíve drained and cleaned out the filter itself with dilute bleach and replaced the filter cartridges. The skimmers seem to be working appropriately and Iíve been keeping them and the pump basket clear.
A note on my alkalinity level - The pH of the pool was initially low (less than 6.8) and I made the embarrassing mistake of trying to adjust it with baking soda instead of soda ash or borax (I ended up adding a lot of baking soda). I did manage to get it up to 7.2 but, of course, now the alkalinity is high. Iím trying to follow the process of lowering the alkalinity by raising the pH (using a primitive waterfall-type feature- you can see it in one of the pictures).
A note on CYA level - The TF100 kit includes a 50 ppm CYA standard, which is great practice for performing the test. Unfortunately, when I used to 50 ppm CYA standard, the black dot is not totally obscured when the test tube is filled to the 50 ppm mark. Itís mostly obscured, but not entirely. For me it becomes totally obscured around 35 ppm. My pool water is pretty similar - mostly obscured around 40-45 and totally obscured around 30-35. Not sure if this means that the standard is wrong, or Iím looking too closely. It would be nice to know although, either way, my CYA shouldnít be more than 40-45.
Appreciate any help or suggestions you folks have.