DIY - Muriatic Acid Dispenser

[sergey]

Hello All
I've got a swim spa from Arctic Spas - So far happy but :
My HP level is rising too quickly and I can add acid only every 2 weeks. (it is too high on day 4 already)
So, I have an idea to design and build a small acid floating Dispenser. (wi-fi)
Would like to know if it is a stupid idea or not - Feel free to express your opinion.
Thank you !
Design could be like this  : https://drive.google.com/file/d/1kts6qKq9Eakf-xpd7mBVbWxlYzgP1kxo/view?usp=sharing

[Tman122]

I would worry about concentrated acid getting on stuff (shell, filter housing, ect.) as the floater settles where the current takes it. I always dilute muriatic acid in 5 gallons of water before adding it to the tub. And I pour it in the center carefully.

[Tman122]

I would worry about concentrated acid getting on stuff (shell, filter housing, ect.) as the floater settles where the current takes it. I always dilute muriatic acid in 5 gallons of water before adding it to the tub. And I pour it in the center carefully.

In other words scoop a bucket of water out of the tub, mix and return.

[sergey]

Yes - I thought about that but :
1. battery operated dosing pump will supply a very small amount - let say 1 ml per minute. (if it is still an issue it can be showered down more - let say drop by drop)
2. the acid output hose could be ended with a small plastic perforated container  where acid will mix with water a bit before entering the spa without touching anything but this container directly.
3. As I understand M.acid does not really react with (damage) plastic - Am I wrong ?

here is a newer picture : https://drive.google.com/file/d/1AXLD1mgj5ZmFcm6BCxdAsF3LbFnWlZ0C/view?usp=sharing

[Tman122]

When you float something in you spa where does it end up in a day or two?

Lets talk about why your PH goes high so much so quickly. What are you using to sanitize and how?

You said you can only get to it every couple weeks? Do you only use it every couple weeks?

[sergey]

In my particular case it does not matter because I can turn on all jets remotely during acid dosing.
As an alternative solution it could be a wide floating ring to be placed around the floater to do not allow it to be too close to let say filters.
Another solution is to equip the floater with a motor to move it while dispensing

I have no floater at this moment - can not tell where it prefers to stay

[sergey]

Yes - I use it only once a week or once every 2 weeks.
it is Arctic Spa + salt system(spa boy). - chlorine.
salt system drives PH up naturally.
I am still new to water treatment (3 weeks)
I have feeling that PH should not rase that fast - maybe I did not lower it enough before I left (I believe it was about 7.7, raised to >8.2 in 3 days) ...
probably I can manage that but having a control over Ph level remotely would be great

[Tman122]

Yes - I use it only once a week or once every 2 weeks.
it is Arctic Spa + salt system(spa boy). - chlorine.
salt system drives PH up naturally.
I am still new to water treatment (3 weeks)
I have feeling that PH should not rase that fast - maybe I did not lower it enough before I left (I believe it was about 7.7, raised to >8.2 in 3 days) ...
probably I can manage that but having a control over Ph level remotely would be great

Lower it to 6.8 or even less and see how fast it goes up.

Stabilize your alkalinity around 120 also

[sergey]

Yes - it is the exact plan for my next visit

[Hottubguy]

Yes - I use it only once a week or once every 2 weeks.
it is Arctic Spa + salt system(spa boy). - chlorine.
salt system drives PH up naturally.
I am still new to water treatment (3 weeks)
I have feeling that PH should not rase that fast - maybe I did not lower it enough before I left (I believe it was about 7.7, raised to >8.2 in 3 days) ...
probably I can manage that but having a control over Ph level remotely would be great

Lower it to 6.8 or even less and see how fast it goes up.

Stabilize your alkalinity around 120 also

I would keep alk lower then 120. I would keep it closer to 60. Should reduce ph climb somewhat. I have had luck using Boric Acid in my tub. Keeps PH fairly stable (have a salt tub as well). I went from adding ph down every week to 10’days to once every couple months

[sergey]

I will try all that in time will start from A.120 and if does not work will lower it down.
Boric Acid - Is it just Borax from a hardware store ?

Here is some info from web :
A disadvantage of borax is that its own pH level is very high, around 9.5, and when it's added to a pool in large amounts, it will significantly raise the water's pH. A solution is to also add muriatic acid or another pH-reducing product when adding borax, to bring the pool's pH back in line.

I am still interested in a liquid floater - dispenser.
It also can be used for chlorine injection for regular spas ...