spring startup

[PoolDoc]

Janet's right, of course.

But, why do you want to raise your TA? It's a fiberglass pool. With your CYA that high, you are going to have to run VERY high levels of chlorine to avoid algae. Using bleach won't lower your CYA; it will just keep it from going higher.

You'd be better off adding borates (and acid) to get additional pH stabilization in the water. LOW carbonate alkalinity -- the part of TA that baking soda raises -- inhibits algae. High borates ALSO inhibit algae. On your pool, 6 boxes of borax, plus 2 gallons of muriatic acid should get you there.

Read this thread: http://www.poolforum.com/pf2/showthread.php?13111 about using muriatic safely.

[jarsch]

When testing water with regents does temp ( 50 F ) affect readings Thanks Jerry

[PoolDoc]

I don't think so, but it will slow reaction times, so you may want double or triple the time you wait before reading, especially on the chlorine and CYA tests.

[jarsch]

how much bleach is needed to shock pool 6500 gal fiberglass pool thanks Jerry

[Watermom]

In your pool, each quart of 6% bleach will add about 2.3ppm of chlorine. Shock level needed is based on your CYA level. See more about this in the Best Guess Chlorine Chart in my signature below.

[jarsch]

Would like to thank you all for all the help it has made pool care a lot simplier. Determining when to shock have a taylor k-2006 test kit My reading are CL 1.6- COMBINED CL 0.5- PH 7.4-AL 100-HARDNESS 180-CYA 40 .what would the readings be if I need to shock pool? again thanks Jerry

[PoolDoc]

If you are not having any particular problems, adding enough chlorine 1x per week, to take you up to the Best Guess shock level, certainly provides some safety factor.

Also, if you were using the 0.2 ppm / drop dilution of the DPD-FAS test, then 0.5 CC is a bit high, in which case a shock dose would be appropriate now. BTW, you do NOT have to stop swimming when you shock, except to give the chlorine time to mix.

[jarsch]

Is CC what determines if you need to shock ? And what is the normal reading if you don't need to shock? again Thanks Jerry

[PoolDoc]

There's no absolute answer; most of the time, if it's more than the minimum reading, shocking is a good idea. But, some pools tend to run a bit more CC, and if it's not causing a problem . . . then it's not a problem. The minimum reading is 0.2 with the 0.2 ppm drop test, and 0.5 with the 0.5 ppm drop test.

[jarsch]

Thanks,
Jerry