CSI Question?

[dlambe5]

I am fairly new to this board and have been doing a ton of research. I am attempting to get my water balanced before the warmer weather hits. I am using a Taylor K2006 Kit.

Test results:
Chlorine= 3
PH= 7.5
CH= 375
CYA= 40 (I just added cyanuric acid to raise this. Waiting a week to retest)
TA= 40 (I will raise TA in a few days because I just added CYA)
Temp= 74deg
In pool math the CSI comes to -0.73

When I hover over the CSI number with my mouse it states that "potential to become corrosive to plaster". Even when I pretend that all of my numbers are matching my goals, I get a CSI of -0.43 and the same message of "potential to become corrosive to plaster". Am I completely doing this wrong? Am I on the right track to getting my water balanced? Thanks in advance.

 

[atttech-2]

You are on track. Once you get the TA up CSI will be more in line.

 

[Texas Splash]

Monitoring the CSI row is a good thing, but as you may have noticed, the pH, TA, and CH are the main drivers in that CSI result (water temperature a little too). Once you take into account the TFP "Recommended Levels" (link below), then you can see the NOW and GOAL results of the CSI. At the moment, your TA of 40 is a bit low, so when the pH gets low it really driver-down the CSI. Experiment with the calculator. Raise that TA to about 60 and perhaps the pH slightly to 7.6-7.7 and you'll see the difference that has on CSI.

Also, no need to wait on adding anything. Adding stabilizer doesn't prohibit you from adding some baking soda for TA. Also, on a side note - you probably should increase that FC right away. An FC of 3 is the minimal level, bordering on too low which opens you up for algae. I would keep the FC at the 5-6 mark as much as possible.

Hope this all helps.

 

[dlambe5]

Thanks guys. I was just thinking cya is an acid and baking soda is a neutralizing agent. Maybe I'm over thinking it. Haha.

 

[JoyfulNoise]

Thanks guys. I was just thinking cya is an acid and baking soda is a neutralizing agent. Maybe I'm over thinking it. Haha.

The term "acid" for an organic compound like CYA is a bit misleading. It is a weak acid. Once it dissolves into your pool water it will immediately form the deprotonated cyanurate anion as well as on of two chlorinated cyanurates. It will have very little effect on you waters overall pH. As well, baking soda is sodium bicarbonate which is a fairly weak base and doesn't change the pH of your water all that much.

You can add the CYA and then the baking soda without any concerns.

 

[pooldv]

Managing your CSI makes things better in your pool over the long term. It can make your plaster last years longer. Sort of like changing the oil in your car. Nothing will happen tomorrow if you don't change the oil today. But, one day you will regret it. One day you might have scale build up or your SWG is all gunked up or your plaster is rough and pitted. Here is more information about CSI.

Langelier and Calcite Saturation Indices (LSI and CSI)
Pool School - Calcium Scaling