Watergram / CSI Questions

[floridarandy]

20 year old, 17000 gallon rectangular pool resurfaced with quartz 60 days ago. Testing with Taylor K2006.

Today's test results with water temp 87-88 F

FC- 2.5 (try to keep this around 4)
pH - 7.6
TA - 65
CH - 260
CYA -30 (although probably 0 since none added since resurfacing and using liquid chlorine)

Watergram and PoolMath show CSI as "Balanced". Does this trump pH a tad high, TA a tad low and CH a tad low? By this I mean should I be running the pool focused more on Watergram/CSI as goal or the numbers specifically on each test?

Also, other than using chlorine more quickly is there a downside to low/no CYA? We're heading on vacation in two weeks and I'd planned to use chlorinating tabs which would end up moving the CYA up some regardless. Prior to resurface I'd used tabs exclusively with the result the CYA was always off the charts and I don't want to go there again.

Thanks

Randy in Florida

 

[JVTrain]

CSI is the important number. The TFP Recommended Levels are such that they should place you in the proper CSI range. Your hardness is a little low, but I would not add as that number tends to climb on its own in a plaster pool and in most places fill water can be higher than that. I wouldn't raise TA either as that will likely just increase the rate of your pH rise. Allow your pH to live slightly higher due to this "low" CH and "low" TA to keep things balanced from a CSI standpoint.

You can certainly use tabs while you're gone with your current CYA being lower than recommended for your location. Using tablets is great as long as you know how it will affect your pool for a short term use. I would recommend putting them in a tablet floater and not in your skimmer, especially when on vacation. This will limit chances of damage if your pump should stop running or the tablets get coughed out of the skimmer and end up resting on your pool bottom.

 

[chem geek]

You also don't have to precisely nail a zero CSI. Being off by small amounts is not a problem which is why the Recommended Levels ranges mostly work.