brown stain along water line

[Krulligo]

I use one of these for my spa dosing, it works perfectly.

 

[Olivera]

Should always purge a new tub with ahh-some. Those tubs get filled at the manufacturer for testing and leak detection. Then they are drained after they pass. Residual water stays in the plumbing and then the tub sits until it gets sold. Lots of nasties can grow in that time.

As for borates in Canada I use 20 Mule Team Borax. Get it from Home Depot or Canadian Tire here in Canada. I have a 380g tub as well. For 50ppm borates you need to add 650g of borax then counter the pH with 320ml of muriatic acid (usually I need a little bit more acid after it stabilizes). I usually pre-dissolve half the borax, pour it in with jets running for mixing, then about 15mins later I pour in half the muriatic acid very slowly. Then let it mix again and repeat with second half. Total cost in Canada to do this is after each refill is around $4 or less.

been looking into the boric acid powder I bought and worried about handling it safely. Might do your borax with Muriatic acid instead. Could you expand on the technique? You mentioned first dissolving the borax, would that be in water? Thanks!

 

[Olivera]

I use one of these for my spa dosing, it works perfectly.

View attachment 502512

Exactly what I was looking for, thanks!

 

[Mdragger88]

been looking into the boric acid powder I bought and worried about handling it safely. Might do your borax with Muriatic acid instead. Could you expand on the technique? You mentioned first dissolving the borax, would that be in water? Thanks!

The boric acid is just fine to use especially since you already own it- it is much simpler than using borax & muriatic acid separately as it’s nearly ph neutral. Just dump it in & it almost instantly dissolves.
Boric acid has been used for years in eye solutions & “women’s health products”.
As with any powdered/granular/dry product don’t inhale it & you’ll be fine.

 

[Krulligo]

been looking into the boric acid powder I bought and worried about handling it safely. Might do your borax with Muriatic acid instead. Could you expand on the technique? You mentioned first dissolving the borax, would that be in water? Thanks!

I dissolve half of the borax in a bucket of water, takes a bit of stirring but eventually most goes into solution. Once dissolved, I dump it into the tub with jets running. After I very slowly pour half of the muriatic acid needed when jets are running. Let mix for 10-15mins. Then repeat with other half. In my tub, the end result is still a bit basic, so I measure how much acid I need to finally bring pH back down to about 7.4. Then you are done.