CH level range discrepancy

[Nordy-que]

Just wanting to understand why TFP recommends a CH level that is quite a bit higher than what I've seen elsewhere. My pool warranty sheet, for example, gives a range of 200-400, while Poolmath is saying 250-650, with 350-550 being ideal. Mine is at 300. I'm inclined to stay there unless there is a really good reason to go higher...

 

[mknauss]

The Recommended Levels, specifically for plaster pools, are designed around maintaining a safe CSI level so that the water is neither aggressive to your plaster finish nor in the scaling tendency range. The wide ranges TFPC has for the levels allow more flexibility in achieving those results.

Your level of 300 ppm CH is in range. No need to change it.

 

[Nordy-que]

The Recommended Levels, specifically for plaster pools, are designed around maintaining a safe CSI level so that the water is neither aggressive to your plaster finish nor in the scaling tendency range. The wide ranges TFPC has for the levels allow more flexibility in achieving those results.

Your level of 300 ppm CH is in range. No need to change it.

Makes perfect sense, thanks!

 

[Sanford35000]

This is confusing to me also.

The recommended range for CH on other pool web sites and test strips is ridiculously inconsistent:

clorox test strip: 175 -275
hth test strips: 200 - 400
blog.intheswim.com: 180 - 220
swimuniversity.com: 200 - 275
ultimatepoolcare.com: 200 - 400
taylortechnologies.com:200 - 400
troublefreepool.com: 250 - 650

The above ranges are for a concrete or plaster pool.