Had Water Tested Now Puzzled

[giveituplouie1]

We have Intex 32 x 12 pool that holds 7600 gallons of water with a pump that does 2500 GPH. I've been testing with the HTH kit from Walmart. I thought my level were good, but then I had it tested at the pool store. The numbers are different on pH, Alkalinity, and Calcium Hardness. My question is should I try to bring these more inline? Also my combined chlorine seem high? I've been using the BBB method and the water looks great. I'm probably cleaning with vacuum every other day and trying to keep as much I can out of the pool. One more thing the chlorine hardly ever moves in the last week I only had the floater in the pool and have not added any liquid chlorine. I'm not sure but this the first year with a solar cover ( uncovered during the day and in direct sunlight from 10am till 4pm ) and stabilizer



My Test:
TC 3
pH 7.2
Alk 90
CH 220
CYA 35

Pool Shop Test:
FC 1.6
CC 1.3
pH 7.6
CH 120
CYA 35
Alk W/stabilizer correction 50

 

[JasonLion]

Welcome to TFP!

Keep in mind that test results are not perfect, the same water can give different results even if you do everything correctly. Also, while there are some good pool stores, many of them are quite incompetent and will make large errors when testing water.

When the HTH actually gives a reading it is generally quite good. It is sensitive to high chlorine levels and metals in the water, but you don't have high chlorine levels and metals in the water prevent you from getting any reading on the calcium test, so I doubt you are having any problems there.

If your CC is really 1.3 you should shock the pool. CC at that level should cause the color on the HTH chlorine test to shift from the FC number up to the TC level over several seconds.

The only numbers you really disagree with the pool store on are PH and CH. Everything else is within testing variability. The HTH PH test is quite good, I would go with your numbers on this. CH is more difficult to guess at. Since you have a vinyl liner I wouldn't worry about it. CH doesn't really mater in a vinyl pool.