Just received my TF100 and have a couple questions

[BoyWonder]

Just received my test kit and since my pool is being filled tomorrow I wanted to practice on my UG fiberglass hot tub.

Here are my reading if I did correctly.

FC 10
TA 130
PH about 7.4
CYA 30
CC .5

My hot tub is at 95 degrees. I could not find any charts for hot tubs so I was wondering how my reading look? Do I need to adjust anything?

Like I said I'm just trying to get some practice before the real test starts this weekend. All I have used up till now are test strips.

 

[257WbyMag]

Well, aside from the FC being high in relation to your CYA, it all looks good.

 

[BoyWonder]

Ok thanks. My chlorine levels drop very fast and even though we keep tub covered and only use about once a week I add chlorine about every other day. Do you think this is because my CYA is on the lower end? This is the first time I ever checked CYA.

 

[PoolGuyNJ]

The CYA level is fine using bleach. Spas, when hot, use more FC than pools. I like bromine tabs better, No CYA needed, fewer fumes, and spa covers seem to last longer than with chlorine. Three or four tabs per week, depending on the spa size and your water is good for about 4 months due to the low usage. A higher bather load would justify a water change at 2,5 to 3 months.

Scott

 

[chem geek]

Basically, you want to test your FC level just before your soak. At that point, you'll probably want it around 2 ppm so that you don't notice the chlorine during your soak. Then immediately after your soak, you dose with sufficient chlorine to handle your bather waste and to be able to again measure 2 ppm FC before your next soak. You adjust your dosing up/down for this to happen. If you were to measure the FC soon after dosing, then the FC may be very high but that's OK since that is what is needed to oxidize the bather waste and it will drop within hours and certainly by the next day.

If you want greater disinfection because you have non-family members using the tub, then you can have the FC be higher, say around 4 ppm, to prevent person-to-person transmission of disease.

 

[BoyWonder]

Great, thanks for all you help.