Do Acid Feeders exist for salt water pools

[mnittler]

Is there any type of Acid (pH minus) feeders that can be used with chlorine generators in salt water pools to keep the pH near where it should be. I was thinking something like the in-line or floating chlorine feeder style. Just something to add nearly the right amount of acid to keep the pool near balance until it could be checked. Like to use while on vacation or all the time for that matter. The pool installer was offering me this multi $1000 dollar electronic contraption to control the chlorine and pH but that is not what I am looking for. I just want something simple and cheap to dribble a little acid in all the time that could be adjusted as needed to find the sweet spot.

[kelemvor]

They exist, but as you noticed are a little pricey. Not to mention if you have one and it fails and brings the pH too low, it could seriously damage your pool. There are some other options; watermom has written up a detailed post on some ways to minimize pH rise in swcg pools: http://www.poolforum.com/pf2/showthread.php?16849-Minimizing-pH-rise-in-SWCG-pools

Item #6 had a big impact for me, and the instructions for how to do it safely can be found here: http://www.poolforum.com/pf2/showthread.php?18597-Adding-Borax-to-Make-your-Pool-Resistant-to-Algae

In my case I found I can go about twice as long between doses of muriatic with the borax; although I have to add twice as much when I do. Since it inhibits algae growth you may be able to get away with slightly lower output on your swcg as well (which will in turn reduce aeration that causes pH rise).

One more thing not mentioned in watermom's post. If you have any water features such as a waterfall, or even have the return eyes pointed so they are rifling the surface of the water - those will cause the pH to rise faster. Turn the eyes downward, and turn the water features off - both will help you.

I asked about one of the systems you reference just over a year ago. Check out the responses about the systems for more details: http://www.poolforum.com/pf2/showthread.php?11936-Hayward-Sense-amp-Dispense

[mnittler]

Can a chemical acid metering pump (proportional type) be used that is connected to the same power source signal that controls the Chlorine Generator cell unit? This way at least a little acid will be entering the pool while the unit is generating chlorine. I guess one would also need to know the estimated size of the acid metering pump required in some units (gallons per day, oz/hr, oz/day)? Anybody have an estimate of how much acid they put in the pool per day, week etc. per 10,000 pool size or some similar units as a starting point. I would also need to know the estimated time the cell was in operating.

[JimK]

They exist, but as you noticed are a little pricey. Not to mention if you have one and it fails and brings the pH too low, it could seriously damage your pool. There are some other options; watermom has written up a detailed post on some ways to minimize pH rise in swcg pools: http://www.poolforum.com/pf2/showthread.php?16849-Minimizing-pH-rise-in-SWCG-pools.........

I pretty much folllow that advice, except my TA has been 90-100 and my borates at about 60. My pool seems to have stabilized at about 7.6 and I haven't had to add acid since the middle of June.

[mnittler]

In that case then it probably won't be a big deal. I had thought that Acid needed to be added every day.

[kelemvor]

I end up needing a dose about every two or three weeks.

[JimK]

In that case then it probably won't be a big deal. I had thought that Acid needed to be added every day.

:eek: Thank goodness there's nothing I have to add every day! (Well, technically chlorine, but the SWCG takes care of that ;) )

[JimK]

I end up needing a dose about every two or three weeks.


I use to add acid when the pH hit 7.6. At that time I was adding acid every week. Following the advice here about TA/borates and not worrying about adjusting until pH rose above 7.8 made a big difference as I noted above.

[waterbear]

The other part of the pH puzzle is to maintain the CYA at the manufacturer's recommended maximum (usually 80 or 100 ppm) and adjust cell output to maintain the FC at 5% of the CYA (or slightly higher for high usage pools or pools without 50 ppm borate). The explanation is somewhat complicated but this will also indirectly slow the pH rise and increase the pH stability.

[CarlD]

To cut the Gordian Knot there's a very simple way to steadily add acid to your pool, assuming your CYA isn't too high, or is even low:

Just load a floating chlorine dispenser with Tri-Chlor tabs.

Tri-Chlor is VERY acidic and will lower your pH or fight the raising of it by your SWCG. It's an effective and far cheaper solution. I've come home from vacations with my pH TOO low from the floaters (oops!).

[waterbear]

To cut the Gordian Knot there's a very simple way to steadily add acid to your pool, assuming your CYA isn't too high, or is even low:

Just load a floating chlorine dispenser with Tri-Chlor tabs.



Sort of defeats the purpose of having a SWCG doens't it? :puzzle:

[mnittler]

To cut the Gordian Knot there's a very simple way to steadily add acid to your pool, assuming your CYA isn't too high, or is even low:

Just load a floating chlorine dispenser with Tri-Chlor tabs.

Tri-Chlor is VERY acidic and will lower your pH or fight the raising of it by your SWCG. It's an effective and far cheaper solution. I've come home from vacations with my pH TOO low from the floaters (oops!).

Then do you turn the SWCG off while you are gone? How does the Tri-Chlor react? Too much Chlorine?

[CarlD]

Sort of defeats the purpose of having a SWCG doens't it? :puzzle:

Since I don't have an SWCG I don't "feel your pain" :D

Seriously, if you have to come up with an automated acid-feeding system perhaps just tri-chlor tabs are enough, certainly easy to set up and replenish. I presume the SWCG will produce less chlorine to compensate.
Of course, the Tri-Chlor will run your CYA levels up.

[kelemvor]

I expect once he gets the levels right (including borates) it will not really be an issue. I bet a floater would require maintenance more often than he will have to add acid; although I'm guessing since I've never used a floater.

[waterbear]

I expect once he gets the levels right (including borates) it will not really be an issue. I bet a floater would require maintenance more often than he will have to add acid; although I'm guessing since I've never used a floater.

Exactly!!!! I have to adjust my pH about every 2 months or so..Not a lot of work. There is no need for a trichlor feeder. And yes, I do shut everything down when I go on vacation and because of the borate return to a pool that, at worst, had been slightly cloudy. I just shock with bleach before I go and again when I come back and I am swimmable in a day or two! If the recommendations posted for SWCG water balance are followed pH rise is basically a non issue.

Trichlor would actually be more work and expense, why pay for it when you have a SWCG anyway?

I would recommend trichlor IF you have new plaster that is still curing but once it does (or in a fiberglass or vinyl pool) there is really no reason to use it.