New owner. First fill - TA/PH issues

[crazycorkey]

Hi all,

I got my new hot tub (467 gal) hooked up the other day and did a 50ppm Chlorine shock and Ahh-some and got some nasty out. Drained and refilled. The day was shot so I let it sit overnight and left it running.

Next day water at 99 deg followed to 3-step bromine method here:

How do I use Bromine in my Spa or Hot Tub?

Originally Posted by waterbear There is a lot of misinformation on the proper way to use Bromine so I hope this primer is helpful. First, you need to establish a bromide reserve in the water. Bromine tablets can do it by themselves but it can take literally weeks until enough dissolves. Some...

www.troublefreepool.com

But started with the water balancing instructions from here:

How do I use Chlorine in my Spa or Hot Tub?

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 didn’t go as I expected...I have the Taylor K-2106

Calcium Hardness read at 100 I raised it to 130.
TA read at 110 and PH 8+ so I started with aeration (30 min while I ran to the store for Muriatic Acid) and then added 2 oz per the table for reducing PH to 7. 30 min aeration later I needed another 2 oz, next cycle 1.5 oz, next cycle 1 oz, next cycle 0.5 oz. 2.5+ hours later after all those cycles PH was always 8+ off the scale when I check 30 min after. Since this wasn’t matching with the instructions for about an hour to lower TA by 100 (I only needed lower by 60) I tested TA and it was 20. Why didn’t my water stop with PH around 7.6 and TA 50 like instructions stated it should? With it getting dark I added Baking soda to what should bring TA to 50 and another .5 oz of Muriatic Acid to reduce the PH from 8 to hopefully around 7-7.2 (I stopped testing) and finished out the instructions.

I added 50ppm Borates via Boric Acid (19oz vol).

Added 30ppm Sodium Bromide

I used Pool Math set current FC to 0 and Target 10 and shocked with 10 oz 6% bleach. Is that the right way to do that?

The water turned a green tint. Is that normal?

Immediately after, I added the floater set to 2 with 4 pucks. And after a few minutes the water turned a blue tint???

Why did my PH never level out?

What’s with the color tints? I dumped the test samples on the ground but rinsed in the spa, is that bad? Did that cause the color tints?

How do I measure FC to know when a shock is done and it’s safe to enter the water with the K-2106?

I’m going to retest everything when I get home from work but any advice would be helpful.

Thanks!

 

[crazycorkey]

Also it has an Ozonator

 

[Tpopz]

A few things:

If your FC is >10ppm, pH test will not be accurate and will register high.

Don’t add boric acid until everything is balanced and stable. Adjustments will require more chemical after you add borates.

I usually give acid about 30min to circulate without aeration to drop pH and TA together, then test to make sure I reached my pH target, then aerate, then test again. Don’t know if it’s necessary to do it this way, but I figure as long as I’m keeping my pH in the 7’s, my tub/heater are safe and my pH usually stays rock solid for a couple weeks after the balancing and borates.

I don’t know anything about bromine

 

[DangerBoy]

The boiling off of CO2 to lower the bicarbonate/alkalinity level in the water will continue to lower TA to levels much lower than 60 if you keep dropping pH and aerating. You should've kept testing as you went along and stopped the process when you hit a TA of 60 or whatever you were trying to get to. At that point you would add acid to get your pH to desired levels (I shoot for 7.5 - 7.6 with my chlorine system), then add either boric acid or borax and acid to get borate level to ~50 ppm, test and adjust your pH again if necessary (ptobably won't be if you were using Pool Math) and then and only then start adding your sanitizer.

You went too far with the TA reduction process because you weren't testing enough along the way, tried to raise iTA up again with Baking Soda, then maybe didn't give that enough time to have its full effect on pH before trying to counteract it with acid based on a guess or calculation instead of an actual measurement and then likely added the borates before you had the TA and pH completely sorted out and dialed in to target levels.

I too have no experience with Bromine so can't comment on the color changes and other things that happened while you were getting that system up and running.

 

[crazycorkey]

Thanks for the input. That’s good to know to keep testing TA. Nitros writeup doesn’t mention that.

Numbers today:
CH 130
TA 50
PH 8+ test with R-0005 was 3 drops to get to 7.4
Bromine 6

Should I keep using Muriatic Acid to lower the PH? Is there a PH down I can buy that will only affect that?

 

[Msch99]

Try looking here.

Recommended chemicals

 

[DangerBoy]

Your TA, TC and Bromine numbers look good. Just need to drop that pH to about 7.5 and you're golden.

Yes, keep on using Muriatic for lowering pH. All acids have the same effect and the same use which is primarily to lower pH. It's used in conjunction with extended periods of aeration to to lower TA but so long as you don't drive pH down low with acid and follow that with long periods of aeration, using any type of acid and short periods of aeration just to tweak your pH shouldn't have much effect on your TA levels.

You can use either dry acid (the powdered pH down product all of the pool chemical companies sell) or a liquid acid for lowering pH. Anything to get H+ ions into the water. Muriatic is pretty much just HCl and is probably the easiest and cheapest strong liquid acid you can get and it's cheaper than dry acid so just go with Muriatic unless you're worried about having a jug of strong liquid acid around from a safety point of view. Like if you have young kids and you're worried they'll get into it and you don't have a secure place to keep it.

Use the Pool Math calculator to figure out how much acid you need to get your pH to 7.5, add exactly that amount and run the jet pumps a few minutes to get it circulated and you should be all set. Thereafter, you'll probably find that your pH level stays fairly stable so all you'll need to do most of the time is maintain the bromine levels.