Manufacturer recommended chemical balance vs TFP question

[Cornhuskerfan]

First I'd like to thank you all for the wealth of information on this forum. You have guided me through the first summer of pool ownership without fail, through some pretty intimidating times. i've even gotten 2 neighbors seeking the wisdom on this forum.

I have two questions;

Inside the control panel the manufacturer's label has it's recommended balance for the pool chemicals as follows;

FC 1-3 (TFP recommends 4-6)
Ph 7.2-7.6
TA 80-120 (TFP recommends 60-80)
CYA 30-50 (TFP recommends 70-80)
CH 200-400 (TFP recommends 350)
Salt 27-3400

I currently use the recommended numbers that are here on TFP. Maybe I'm just splitting hairs but am curious to know why the difference? Seems to me TA and CYA are quite a bit different, maybe not...

Second question I have is that when I test my numbers, they are always pretty good but my TA seems too high often. I know that the MA I'm currently using has a low baume but I make sure to put the correct % in the TFP calculator. Seems like I have to add MA more often than I should. Thoughts?

Thanks again, you folks are a lifesaver.

 

[mknauss]

The FC is based on the [FC/CYA][/FC/CYA] relationship. Industry does not fully embrace that science.

CYA is based on anecdotal data showing that one can lessen the daily additions by the SWCG if using a higher CYA. You can run lower CYA, you just then must increase your SWCG production to be sure you never let FC fall below minimum at any time.

TA is a range. You might find your pH is better off with a TA outside that range. That is OK. In certain circumstances you might have to manage CSI if you get outside of the ranges shown.

Hope that helps.

 

[DebbieO]

The pool store does not take into consideration the FC/CYA relationship. Which is why my water was a mess! The TFP levels for CYA is 70-80 for SWG pool. 30-50 for a regular chlorine pool. Sorry about your TA question, I rarely have to fiddle with that. My Ph is pretty stable.