Ca hardness question

[moreira85]

Just changed my water in my 400 gal spa. After I filled it up I did a CA hardness test w my Taylor testing kit and got a reading of 30 ppm.
I added about 6 oz of CA increaser last night and when I tested it today I couldn’t get any reading of calcium? When I added the Reagent the water wouldn’t even turn red so CA was not even present today. I just added 5 more oz of CA increaser today.
what would make the CA hardness go down?

 

[Newdude]

. I just added 5 more oz of CA increaser today.
what would make the CA hardness go down?

Nothing can remove Calcium, CYA or salt except draining. Now, in a hot tub, splashout/refilling and rain can help ALOT faster than in a pool, but it is still a slooooooooooooow process. To go to 0 would require a full drain, and even then, you fill water would have at least some calcium in it.

Something else is amiss.

 

[mknauss]

Only reason to add calcium to a plastic spa is to reduce foaming. Do you have a foaming issue?

 

[moreira85]

Currently no foaming issue. I just can’t get the test to turn red when adding R0011. It starts to turn red then goes clear. So CA hardness isn’t important in a tub?

 

[mknauss]

So CA hardness isn’t important in a tub?

No. Too high it might scale. But there is no low limit, except to prevent scaling.