SWG with two lights on

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Elgrecus

Elgrecus

0
Feb 15, 2013
60
Los Angeles, CA
We moved into a new house with a salt water pool and are just getting started on understanding how to maintain it. Our ECO-matic was getting the two red lights on so we bought a TF-100 test kit and salt strips. Here are some results:

Salt: 1000 ppm
CH: 300 ppm

We had hired a pool guy to "take care" of the pool at first but he seemed a little clueless, and it didn't help that the ECO-matic was getting the red lights and he hadn't even brought it up to us. It appears that he never even tested the salt level because it is way below the approximate 4500 ppm that ECO-matic suggests. We suspect that the previous owner never changed the water in the eight years since the house was built. Since our CH levels seem to be normal, is there any need to drain the pool and change the water? I bought 240 lbs of pool salt today and thought I would check whether is was necessary to change the water before throwing the salt in. Any thoughts are appreciated.
 
Ok, I got to doing the full tests today. The results are:

? FC (Free Chlorine)
? Bromine
7.8 pH
150 TA (Total Alkalinity)
300 ppm CH (Calcium Hardness)
20 ppm CYA (Cyanuric Acid)
1000 ppm Salt

I used the Taylor K-1000 to test for Chlorine (and Bromine). The water remained clear and never looked yellow at all, so I am assuming the levels are below the charts lower limit. The chlorine drop test I attempted also never turned the water pink after adding the R-870 powder. Again, I am assuming the level of chlorine is undetectable.

There were a couple of questions I had about performing the tests:

1. In testing for TA (Total Alkalinity), at 14 drops the solution began to turn red. At 15 drops it was more red, and at 16 it was fully red. Which of those three numbers should I multiply by ten?

2. In the Taylor K-1000, chlorine and bromine are tested in the same cell. I am assuming that the numbers below each of the titles ("Cl" and "Br") represent the respective values of chlorine and bromine, rather than the two numbers representing a range (i.e. .5 to 1 in the lowest square, 1 to 2 in the next cell up, 2 to 4 above that, etc.)

This is my first time testing this pool since moving in to the house, so any help is appreciated. As I mentioned, the ECO-matic often has two red lights on indicating there is some problem. After reading the ECO-matic literature, it appears that almost all my test results (expect for pH) are way off their recommendations.

One other note, the general contractor who built this house for himself about eight years ago planted grass right up to the coping and hedges/shrubs that overhang the pool on the other side. He set the grade too high (to top of coping in some areas, so grass is above coping) and I believe that when the water sprinklers run at night, a small amount of runoff is getting in the pool. I also have some organic matter (small leaves and grass from mowing) at the bottom of the pool that needs vacuuming (can't get it with the net). I have since lowered the grade to below the coping and will remove the overhanging plants shortly to keep leaves and such out of the pool. We have a motorized pool cover which helps otherwise the pool would be filled with leaves. I figured this was worth mentioning in evaluating the quality of the water. Any advice is much appreciated!
 
How does you water look?

If it is clear, I would use liquid chlorine/bleach to get up to about 10 ppm tonight after the sun is off the pool and do a OCLT to ensure your algae free. If you pass then I would start putting in the salt and cya. If you fail, then I would start the shocking process and worry about adding salt and cya later.
 
The TF-100 does include the FAS-DPD test. That is the one with the R-0870 and R-0871 reagents. It is the most accurate and can read the highest of the three commonly available chlorine tests (the others being the OTO (K1000) and the DPD).
 
Ok, that must be the one they call the "Chlorine Drop Test" in the TF-100 kit. It uses the R-870 and R-871 as you mentioned. I tried that test and the water never turned pink after adding the one heaping scoop of the R-870 powder. It remained perfectly clear. I proceeded with adding the R-871 solution anyway. No change. The water remained clear.

Am I correct in assuming that I should add bleach to bring up the FC level, and add the salt? If so, can I add them simultaneously? How long should I run the filter for when adding bleach? Thanks again for your help.
 
I had a typo in my post to you...I wrote FA-DPD, and meant to right FAS-DPD (my s key is broken on my keyboard)...sorry for any confusion.

Elgrecus said:
Am I correct in assuming that I should add bleach to bring up the FC level, and add the salt? If so, can I add them simultaneously? How long should I run the filter for when adding bleach? Thanks again for your help.
Click to expand...
Definitely get some chlorine in there using bleach/liquid chlorine. I would do the OCLT I mentioned above before adding salt. Make sure your at at least 10 ppm FC (using the FAS-DPD test) after the sun is off the pool for the test.
 

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Ok, I shocked the pool yesterday evening. I added (4) 120 oz jugs of 8.25% bleach. The TFP article on "The Shock Process" says to "Add enough chlorine to bring FC up to shock level (or a little higher)," but doesn't say what FC constitutes a shock level. I recall reading 24 ppm so that's what I put into the pool calculator. Anyway, here are the results after adding the bleach and letting the filter run for a few hours in the evening before pulling a sample (ran the filter all night too):

PM 06/08/13
FC=2.5ppm
CC=0.5ppm
TC=3.0ppm

AM 06/09/13
FC=1.0ppm
CC=0.5ppm
TC=1.5ppm

So, I don't quite understand. If my target for shock level was FC=24ppm, and I added sufficient bleach to get me there according to the Pool Calculator, the FC level when I tested in the evening a couple hours after adding the bleach was FC=2.5ppm. I did of course experience a big drop in FC overnight. I assume I should continue with shocking the pool until I get the OCLT in line with the recommendations in "The Shock Process" article, correct?
 
The large amount of chlorine you added to the pool was used up by that "slight green tint" you were (and probably still are) seeing. This is called an algae bloom. Keep pouring the bleach to it, until you can maintain shock level.
 
Thanks again. My CYA level (20 ppm) is not on the "Chlorine / CYA Chart", but I will extrapolate. ECO-matic recommends CYA levels between 50 to 80 ppm. Should I add cyanuric acid to get me to an acceptable level during the shocking process, or wait until after my chlorine levels are stabilized?
 
You can, but that will increase the FC you will need to maintain while shocking. Best to get the pool cleared before adding the CYA.

You aren't trying to run your SWCG while shocking, right? All that will do is wear it out. Best to leave it off until you pass the OCLT.

Once you pass OCLT, add your CYA to the required level, then turn on the SWCG.
 
Thank you both. I did turn off the SWCG while shocking, not because I knew better but because the salt level was so low that I figured it would only be taxing the cell. I am disappointed that the pool guy we hired at first didn't alert us to the fact that our salt levels were far below the recommended range. The cell is probably 8 years old anyway. Once I pass the OCLT I will get the CYA right, add the salt I need to get to the right level and see how it goes. It may be time for a new cell. I doubt the cell's been cleaned either in its lifetime. I don't get the feeling that the previous owner had maintenance high on his list. Thanks again!
 
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