I am new to the forum and just went through pumping out about 3' of pool water, at the recommendation of the local pool store, to reduce CYA, Nitrates and Calcium. I want to make sure I am on the right track to avid having to pump out the pool again so I bought a TF-100 test kit and found/joined this forum.
My most recent (self) test results after removing and replacing pool water are as follows:
Prior to removing and replacing pool water, based on a test at Leslie's, CYA was 100 (had been higher in the past) and CH was somewhere between 350 and 400 and Nitrates were 30 (I don't know it that was ppm or ppb but was told it was bad). The rest of the readings were OK.
TA: After removing/replacing the water I added a total of 3.5 gallons of muriatic acid based on TA readings from another test kit which listed ideal readings for TA at 80-100. The newly acquired TF-100 kit lists ideal for a chlorine pool at 100-120. Do I need to adjust this or will it eventually rise on its own? Almost every time I went to the pool store to have a test run I ended up having to add Muriatic Acid, so something happens on its own to lower the PH.
If I need to raise the TA is Arm and Hammer baking soda OK to use?
FC: When I refilled the pool it was pretty cloudy so I initially added muriatic acid to raise the PH and then when it got toward the correct level used 2 pounds of Leslie's Power Powder Plus to shock it and ran the pump for 2 days straight. I then replaced the filter cartridges with new cartridges and monitored the FC level. I had the auto chlorinator turned off since I didn't want to add too much chlorine due to the pump running 48 hours straight. As the chlorine level from the shock dropped and I set the pump to the normal schedule I turned the auto chlorinator on.
CYA: I use 3" tri-chlor chlorine tablets (most recently punched at Leslie's) in the Pentair 320 auto chlorinator and, at the recommendation of the Leslie's to reduce the increase of CYA, a non-chlorine shock call Fresh N' Clear. However, our chlorine levels fluctuated all over the place from 0 to over 5 and we ended up with algae. So they recommended using their Power Powder Plus whenever the FC got to 0.
Re the auto chlorinator, I replaced the check valve in the bottom, made sure it was not clogged and still had the problem with chlorine levels all over the place. We set the knob from 3 to 5 and never could get it consistent this summer It worked fine the last 2 years. Could the inconsistent FC have had something to do with the high CYA levels we had? At the suggestion of the pool store I replaced the lower hose to the auto chlorinator with a longer hose that lets water in to the top of the cylinder rather than filling from the bottom.
I know the forum lists liquid bleach as a way to go, but the guy who installed my pool recommended against it since it was not stabilized and would lead to inconsistent chlorine levels. Since I have had that lately anyway, is the liquid bleach the way to go and if so, how do I make the transition?
Weekly treatments: I add 1 pound of shock (Fresh N' Clear) on Sunday mornings and 2.5 capfuls of Pool Perfect + PhosFree on Tuesday mornings. The PhosFree keeps our phosphates level in check. It had been over 3000 and using the PhosFree keeps it at 0 (we have a bunch of Crepe Myrtles in our yard that supposedly contribute to that high level).
Nitrates: I don't know where it came from how to test for nitrates, but we don't use any fertilizer near the pool.
Pump Schedule: I run the pump at the following times:
8am - 12pm 3000 RPMs (booster pump with Polaris runs from 8am - 11 am)
12pm - 8pm 2000 RPMs
8pm - 10pm 700 RPMs
In the past I had it running at 450 RPMs from 12pm to 4pm and then at 2000 RPMs from 4pm to 6pm but found that the auto chlorinator would not fill with water unless the pump ran at at least 1400 RPMs.
18,000 gallons Chlorine Pool
Pentair 520 Cartridge Filter
Pentair Intelliflo Variable Speed Pump
Polaris 280 with Polaris booster pump
TF-100 test kit
Pentair/Rainbow 320 auto chlorinator