Beginner Pool Questions

[crokett]

Hi. We got our first pool this year. You can see my sigline for current pool info. I am currently using 1" stabilized tablets but want to get away from those into probably bleach. The bleach is cheaper, and I know exactly what I am putting in the pool. Plus I've put about half a bottle of tablets into the pool over the last few days. I just treated for mustard algae this morning so I imagine that is where the chlorine has been going.

I have a liquid drop-type test kit. Current numbers are

chlorine 4PPM - does my kit measure total or free? The liquid is reacting to free, and the used chlorine is stable, no?
pH is 7.6
Alkalinity is 150PPM - my research says there is disagreement on whether that is high or not at least for vinyl.


Stabilizer - I know mine is low. Is it necessary to get a kit that can measure stabilizer? As I understand it stablizer stays in the water so I should be able to get it tested once, find out how much I need then add that and the bleach?

Pumps - apparently no one can agree on whether running at night or during the day is better. The only thing that makes sense to me is running it at least long enough to get the water through once.

thanks

 

[JasonLion]

Welcome to TFP!

Most of the test kits only test total chlorine. The most common one is the OTO test which shows various shades of yellow and reads from 0 to 5 ppm of total chlorine.

You need to know your stabilizer (CYA) level. If you want to get that done at a pool store that is fine. But a good test kit is one of the best investments in your pool you can make. Even the HTH 6 way kit at WalMart (under $20) has a CYA test. Much beter is the TF Test Kit.

If your electric rates vary by time of day then run the pump at night. If they are the same at any time then run it whenever is convienent for you. Many people like to have the pump running when they are swimming.

The ideal level for alkalinity is between 80 and 120, but 150 is fine in a vinyl lined pool. Higher alkalinity levels may cause your PH to rise, so keep any eye on your PH and make sure it doesn't get too high.

 

[MikeInTN]

Your test kit is probably measuring total chlorine, unless it specifically states it's measuring free chlorine. Some of the test kits will measure both free and total chlorine. Check the instructions that came with your kit.

Your TA is a little high for my liking, but probably tolerable, as long as your pH is OK.

If you have a pool store that will test your water for you and you trust their test results, then you can probably get by without a test kit for stabilizer (or CYA). You'll want to test after adding stabilizer and waiting for it to dissolve to make sure your level is where you need it to be. There are some threads on the forum here where some folks have added what they thought was the proper amount to bring them to a certain level, only to find out that something was wrong with the stabilizer they purchased, as it didn't raise their level near as much as they calculated it would. Once you get it to the required level, say 30-40 ppm, then you should be good throughout the pool season. If you winterize your pool, you'll want to check it again when you open the pool, as there are reports of some anerobic bacteria that can develop in your pool over the winter that eat CYA, especially if you have an algae bloom over the winter. Again, personally I like being able to test for this myself. My local pool stores aren't the best at giving accurate test results.

I run my pump from 6am to 6pm, because we only swim during the daytime hours, and the wind dies down here in the evenings, so hardly anything gets blown in the pool overnight that needs to be removed from the water. I get at least two turnovers of water during that 12 hour run. My pump is a single speed pump, though. I think those that have two-speed pumps leave the pumps running longer on low speed to get the turnover they need. Running the pump on low speed saves on electricity usage, even at extended run times ( from what I've read) because the low speed setting uses something like 1/4 the power the high setting uses.

 

[crokett]

Ok... so why does the kit test total chlorine? I thought only the free chlorine was useful, meaning it is what is availble to kill things in the pool? I think I'd rather know what free chlorine is than total, correct?

 

[JasonLion]

Right, you want to know FC far more than you want to know TC. However the chemistry required to distinguish between the two is somewhat complex. No one has come up with an inexpensive FC test, so the cheaper kits only include the TC test. Besides, you normally try to keep CC at zero, FC and TC are the same when CC is zero.

With the OTO test it is possible to get a sense of the combined chlorine (CC) level, and thus hints at the FC level. The OTO test will change color about 15 to 40 seconds after you add the drops when CC is present. The amount of color change is suggestive of the amount of CC. If you are quick and able to distiguish the various shades of yellow well you can get a guess at the CC level by seeing how much color change happens.