Break even point - shock

[seanauld]

Firstly, let me thank all who contribute to this site and the owner/operator. Being a new hot tub owner, I have learned more here in the last month than I thought I needed to learn. The altruism displayed here is nothing short of impressive.I have a quick question as it relates to shocking. The hot tub manufacture , beachcomber (430 gallons, dichlor for the moment) advises to to add 2 1/2 TBs each week of their Carefree Boost - their dichlorvos sanitize each week. This causes the chlorine to jump into the teens, and obviously we can’t use it for approx. 24 hours. When I measure the free Chlorine pre-shock it is usually around 3PPM, with combined chlorine around .5 PPM. If I understand correctly, I need to add 10 Xs the combined CC, which in this case would be enough to bring up to 5 PPM ?

If I added less than the 2 1/2 TBs , but enough to bring up to , in this case 5 PPM, would I have effectively shocked the hot tub.

Many Thanks
Sean

 

[Mdragger88]

You should follow the FC/CYA Levels to determine your shock/slam level which may be quite high if your primary source of fc is dichlor. Dichlor adds as much stabilizer as it does fc to the water - the fc gets consumed quite quickly but the cya/stabilizer stays & builds up.
Here’s a handy guide for using chlorine in your spa

How do I use Chlorine in my Spa (or pool)?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.troublefreepool.com

It is also pinned to the top of this forum for convenience

 

[JoyfulNoise]

The 10X breakpoint chlorination “rule” is actually wrong. The ASPS and other pool and spa related orgs push that nonsense but it’s incorrect as it’s based on conflicting units of measure. When you take into account the ACTUAL chemistry and use the correct formula units, it works out to about 3X. Even so, if a tub is properly chlorinated and run correctly, you don’t need to worry about breakpoint chlorination unless your are using the tub multiple times per day or you have a huge bather load. Even if CCs build up the the fix is simple - drain the tub and start over.

Don’t forget to follow the Ahhsome purge procedure for your tub. Biofilm build up in the plumbing is the primary cause of FC demand in a tub aside from actual bathers.

 

[seanauld]

You should follow the FC/CYA Levels to determine your shock/slam level which may be quite high if your primary source of fc is dichlor. Dichlor adds as much stabilizer as it does fc to the water - the fc gets consumed quite quickly but the cya/stabilizer stays & builds up.
Here’s a handy guide for using chlorine in your spa

How do I use Chlorine in my Spa (or pool)?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.troublefreepool.com

It is also pinned to the top of this forum for convenience

Thank-you Mdragger88, I had read the post and concerned about the cumulative effects of the CYA, me so was trying to see if I could minimize my addition of Dichlor. Will transition to bleach or bromine soon, though with the kids heading back on Tuesday was trying looking to keep the tub running until after the confusion dies down.

Many thanks
sean

The 10X breakpoint chlorination “rule” is actually wrong. The ASPS and other pool and spa related orgs push that nonsense but it’s incorrect as it’s based on conflicting units of measure. When you take into account the ACTUAL chemistry and use the correct formula units, it works out to about 3X. Even so, if a tub is properly chlorinated and run correctly, you don’t need to worry about breakpoint chlorination unless your are using the tub multiple times per day or you have a huge bather load. Even if CCs build up the the fix is simple - drain the tub and start over.

Don’t forget to follow the Ahhsome purge procedure for your tub. Biofilm build up in the plumbing is the primary cause of FC demand in a tub aside from actual bathers.

 

[seanauld]

Thank-you Mdragger88, I had read the post and concerned about the cumulative effects of the CYA, me so was trying to see if I could minimize my addition of Dichlor. Will transition to bleach or bromine soon, though with the kids heading back on Tuesday was trying looking to keep the tub running until after the confusion dies down.

Many thanks
sean

 

[seanauld]

Thank-you Mdragger88, I had read the post and concerned about the cumulative effects of the CYA, me so was trying to see if I could minimize my addition of Dichlor. Will transition to bleach or bromine soon, though with the kids heading back on Tuesday was trying looking to keep the tub running until after the confusion dies down.

Many thanks
sean

Many thanka joyful noise, I wasnt aware and so very good to know. I will get some cleaner before the drain……
sean