Stabilizer

[mknauss]

Disregard...ordered K-2006C

That is great. The TF100 with Speedstir is the better value, but the K2006C will work fine.

 

[MCF50]

I suggest you stop making any adjustments based on your 5 way kit but to keep enough chlorine in the pool for the yellow tinge to be in the OTO test. The pH may be able to be believed if the TC you are reading with the OTO is low enough.

OTO?

New test kit comes tomorrow. I'll post all findings and them hopefully be able to add the 4lbs of stabilizer to get the 40ppm thru the winter. Thanks!

 

[mknauss]

OTO (Orthotolidine) Test is what your 5 way test uses for TC (Total Chlorine). You cannot test FC (Free Chlorine) with that method. That test is best at telling you that you have chlorine in the water, not at what level with any precision.

 

[MCF50]

Thanks. While I wait for my test kit, what should I have on hand for regular chemical maintenance:
1. I have powdered stabilizer. Once I get PH, CL BR, and alkalinity lined up I will add recommended amount to get to 40ppm
2. I have a bucket of chlorine pucks for my 'feeder' (that is now off)
3. Salt - I have one 45lb bag
3. Meuratic acid?? - cheapest place to get?
4. Sodium bicarbonate?? - cheapest place to get?
5. ???????

 

[mknauss]

You will not be testing BR as that is Bromine and none have or will be added.
You will need liquid chlorine for the winter. Or only raise your CYA to 30 ppm and use the pucks for the winter. Be sure they are dissolving enough to get your FC in target range. Test pH often as the pucks are very acidic. Test CYA monthly to track it. Stop using pucks if it gets to 60 ppm (not likely over winter).
No need for any salt. Will be too cold for the SWCG anyway.
I get muriatic acid at Home Depot. 2 gallon box of 31.45%
Should never need sodium bicarb aka baking soda.

 

[MCF50]

You will not be testing BR as that is Bromine and none have or will be added.
You will need liquid chlorine for the winter. Or only raise your CYA to 30 ppm and use the pucks for the winter. Be sure they are dissolving enough to get your FC in target range. Test pH often as the pucks are very acidic. Test CYA monthly to track it. Stop using pucks if it gets to 60 ppm (not likely over winter).
No need for any salt. Will be too cold for the SWCG anyway.
I get muriatic acid at Home Depot. 2 gallon box of 31.45%
Should never need sodium bicarb aka baking soda.

Thanks. I thought the purpose of the SWCG was to eliminate the need for chlorine? We are in Houston and weather for the next week is 50-65F. How do you know how much to flow thru pucks. Leave it on all the time? Why not just add stabilizer to get CYA to 40ppm for winter?

 

[mknauss]

The SWCG will generate chlorine when the water is warm enough. You will be using less chlorine during the winter.
You will have to adjust on the chlorinator if you wish to use it. You had the pucks so I described how you can use some of them this winter. Up to you. The lower CYA if you use pucks is because the trichlor pucks will add CYA as they add chlorine to the water.

 

[MCF50]

The SWCG will generate chlorine when the water is warm enough. You will be using less chlorine during the winter.
You will have to adjust on the chlorinator if you wish to use it. You had the pucks so I described how you can use some of them this winter. Up to you. The lower CYA if you use pucks is because the trichlor pucks will add CYA as they add chlorine to the water.

Thanks. I prefer to not use the chlorinator as long as the SWCG can keep the chlorine level at the necessary level after adding stabilizer - woudl rather be adjusting one thing rather than two. The SWCG (IC40) is currently set at 50% output. So I understand, if I add stabilizer and get the CYA to 40ppm, I can then just bump up the SWCG output if the chlorine level starts to drop, correct?

 

[MCF50]

You also state above I will not need baking soda; however, per my tests today my total alkalinity is only 30ppm. If it does not come up after using better test kit tomorrow how else would I raise it?

 

[mknauss]

I understand you want to use the SWCG. Just realize it will not work when the water gets cold. So test your FC often.

As I recall the TA of your fill water in Houston is pretty high. So how you got the pool TA down to 30 ppm is interesting. If you find that number to be correct, you will need some baking soda to raise the TA to 60 ppm or so.

 

[MCF50]

So here are the numbers:
Water Temp: 56F
TA: 40ppm
FC: 3.8
PH: 7.6
CYA: <30ppm (stayed clear)
Combined Chlorine: 0.4 (if this makes sense - 1 drop almost made clear / 2 drops made 100% clear)

Based on this I should add ~2lbs of stabilizer to get CYA to about 40ppm. Thoughts??

 

[mknauss]

Sounds good. That will add just under 20 ppm. Once dissolved, wait a few days and retest CYA.

Start using a 10 ml water sample for FC testing. One rounded scoop of powder, each drop of reagent to clear equals 0.5 ppm FC.