I wish i had looked for a form years ago to help out with our pool
I mostly took a water sample several times a summer to local pool supply with good results.
This time I came across a product Agua Chen 4-1 shock + 3" pucks 6+1 at Costco USA. bough last fall.
I though to my self great idea less running around all in one product will try it. Big mistake on my part. We have used this pool for over 25 years.
I was away for several days & came back to a green pool this week.
Great time to try this new to me product 4IN1.
1 bag of 4in1 no change in an hour water still green with swirls of darker green on bottom. 2 more bags no change so I put 1 more for total of 4 bags in over a 3 hour period. + brushed the sides several times.
Checked levels with Insta test strips NO CL on the strip. I now have a white coloured/cloudy water.
Three days have passed & one backwash & added about 2" of fresh city water.
Costco accepted my returned opened & used product.
I also have 2 3" pucks in skimmer Aqua Chem tabs plus (6 in 1)
As you can see from the pic I have purchased some products recommended here, I also ordered a test kit TAYLOR K-2006.
The oldest test kit I have used up to now is a Guardex 4-in 1. the drops are well past best before date.
I"m currently using Aguacheck dip sticks 4 test on a stick. new this year.
Here are the results from the two kits.
FC 3+, PH 6.8 TA 80, CC 3+.
FC 0, PH 6.2, TA80+, CH0-30,
When I receive the new test kit I will post the results and run the test through the (pool-math) what a great tool..