Low Chlorine Problems

[PoolDoc]

If you want to know how much more chlorine it will take, you can get an estimate by doing a chlorine demand test:

Bucket-testing-for-chlorine-demand

But do NOT back off while you are checking: with algae, either YOU are winning, or THE ALGAE is winning. There is no 'coasting'; when you coast for a day or two, the algae will recover, and you are likely to lose 100% of any ground you've gained!

By the way, you NEED TO GET A TESTKIT. Your FC=3.57 ppm result tells me you are using a somewhat bogus digital reader, which in turn tells me, that you don't know -- reliably -- what's in your pool

[CORRECTION from ORIGINAL VERSION: The Lamotte Color Q is considerably better than the digital strip readers, which also produce 2 decimal point results. But the evidence still is that the unit's fundamental accuracy comes nowhere close to 2 decimal points, and does not approach the accuracy of titration methods, like the Taylor K200x series. In addition, there's an intrinsic problem with colorimetric methods for calcium and alkalinity: such methods are inherently logarithmic in progression, rather than linear like titration. Thus, color methods become more and more imprecise as the value increases. So the Color Q may be MORE precise than the K2006 for FC=0.1, but MUCH less precise for FC=10 or CH = 400. Unfortunately, this decreasing precision is masked the digital conversion process, which pump out multi-decimal results, even when the unit can barely distinguish 400 ppm CH from 500 ppm CH!]

Please go get a cheap OTO kit, if nothing else . . . and then dose with bleach till you reach DARK yellow, or orange-tinted yellow.

Ben

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+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ Having a good test kit makes pool care easier for EVERYONE. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon