CH question - too low? Plus numbers check.

[orion6192]

I filled my tub with half soft water and half city water that is really hard.

My beginning numbers look like this:

FC 3.0
TA 200
CH 100
PH 7.6
CYA 5.4 by calculation

Is my CH too low?

My target TA is 65 and by the time I add the 50 ppm of Borates and my CYA gets up 30 by CSI number is:

7.6 PH = -.35
7.8 PH = -.19
8.0 PH = -.06

Also, on a side note... when I've added the acid and let it cycle full air, then check my PH it's always 8.0 or higher. It never really drops during my balancing but check it tomorrow it'll settle in at 7.6 usually. Seems odd...

Thanks -

Scott

 

[YippeeSkippy]

Hey Scott, your CH at 100ppm isn't particularly high. Most spas don't need a lot of Calcium but it helps prevent foaming. I'd leave it alone if you're not having a problem with foam.

Your spa isn't cement is it? My advice then would be different.

The reason your pH is high is that you are mixing the MA in at "full air" is causing aeration which naturally raises pH. A little less wild "full air" mixing should help.

Maddie

 

[orion6192]

Thanks - it's an acrylic tub (Jacuzzi J345)

wasnt sure if if I need to up the CH or not. No foam.

Did the Ahhsome purge again and flush and fill and flush and fill again then balance.

We we seem stable now - we'll check again tomorrow after it settles in.

Thanks -

Scott

 

[orion6192]

So I checked by PH and FC the day after and my results were:

PH = 7.8
FC = 2.0 (number may be a little off - I added 2oz of Ahhsome Maintenance Dose Solution)

I can honestly say after all the trouble I had purging my tub last Labor Day, and the using the Ahhsome maintenance dose once every seven days, I had a small amount of "purge curd" that I scooped out using a fish tank net at the beginning 30 minutes of the the purge and then let the tub sit for for 15 hours and emptied it and refilled it and let it cycle with about 25ppm of bleach, empty and refill and the water is absolutely crystal clear.

My CSI should be about: -.27 given my CYA and PH.

 

[YippeeSkippy]

The CSI isn't really important for acrylic tubs.

 

[orion6192]

Doesn't keeping you CSI slightly negative assist in keeping the buildup in your pumps and heaters to a minimum?

 

[YippeeSkippy]

Yes, but I wouldn't obsess overly much about it. It is very important for cement pools/tubs, just a lot less so for others. Your calcium is low, that's fine.

With a spa I obsess much more over sanitation than the equipment/spa.