CYA Question

[JD57]

I bought a house with a pool and am trying to get it in order. I drained and refilled most of the pool because by several different pool companies and Taylor K-2006 CYA test the stabilizer was somewhere north of 120-150ppm and it got to the point that FC was above 5 and never went down for several weeks without adding any new. And there was a small mustard algae presence.

So after the refill my CYA as measured using the protocol described on this site using Taylor K-2006 is 30.(tried the test twice...) From a pool store they say it is 90. I did this as a check of my own test as these guys don't use the disappearing dot approach. But it is my guess that the charts developed by Ben and by ChemGeek are based on the Taylor K-2006 testing method, so I'm thinking that I go with the 30?

Immediately after filling, I hit it with enough calcium hypochlorite(73 %) to drive the FC to 20PPM, it went down to 10 by the next day, then to 1ppm. Next day again I put in enough to put the FC to 12 PPM,the next day it is 6. So basically what I'm asking is when CYA is around 30 and you've got a pool in texas, is this kind of consumption of FC normal? And is it recommended that I push the calcium up to 250?

Here are the numbers:
FC=6ppm
CC= <.5
PH=7.5
TA=100
CH=210
TDS=500

Pool is plaster and 8500 gals.

Thanks

 

[woodyp]

Welcome to the forum. Texas is gonna require CYA level of 40 to 50. I hold 50, full sun all day, and lose 4ppm still. Higher levels of FC over normal burn off at a faster rate.

 

[jblizzle]

Welcome to TFP!!!

Trust your own testing. That loss seems high ... assuming your pool is clean.

I am guessing you need to SLAM the pool correctly since you claim to have seen algae. [slam:3h8jwrwc][/slam:3h8jwrwc]
And you should switch to using liquid chlorine / bleach or you are going to drive you CH up pretty quick using the cal-hypo. I would leave the CH as is, but just keep your pH > 7.4. The CH is going to rise due to evaporation anyway.

 

[JD57]

Thanks all!