Gone for borates

[Brad_C]

Right, quick history.
Before I discovered TFP my TA was > 190 and I was adding acid every 2 days. I spent a few days with a lot of acid and serious aeration getting it down to ~110. It sat there for a couple of months before I decided to push it down to ~60 as I was still getting pH rise on a weekly basis. Same deal. Acid + aeration. Now the pH is solid at 7.3, hasn't moved in a week and I'm not remotely unhappy with that.

I'm planning to add borates to the pool, and I have boric acid on the way. The problem (as such) is poolmath indicates that boric acid to give me 50ppm is going to drop the pH 0.29 points. So ideally I need to get the pH up before I do that. Theory might posit I should raise the pH with Borax, then add the Boric acid with a qty calculated to give me my 50ppm in total which will bring the pH back down.

That'll give me a mid-range pH, (targeting 7.5-7.6) the right concentration of borates and I won't have to add any more carbonates. Does that sound logical?

 

[ajw22]

I would wait a few weeks and let your pH rise naturally to around 7.5 then add the borates. PoolMath is not always that precise on the effect of adding chemicals to other values. Then you see where your pH ends up.

 

[AUSpool]

I was thinking the same as Allen, just let your pH come up a bit first. Your town water has probably got around 50ppm TA so your TA may slowly creep up a little also. Have you tested your town waters TA and pH? When you get your boric acid add it in a few stages and monitor your pH in between giving time to let everything come to balance.

In order to maintain boric acid really need a test method, the K2006C, speedstir, mannitol, and some other goodies or the Lamotte borate lest strips. I found these in Aussie at; Borate Archives - Test Strips Online

 

[ajw22]

One of the few times we rely on guessstrips - Borates Test Strips

 

[AUSpool]

^ Thought that also. Luckily Borate levels don’t need to be super acurate.

 

[Brad_C]

I'll watch the pH over the next week and see where it goes. I'm fairly well equipped for testing.

 

[Brad_C]

I was thinking the same as Allen, just let your pH come up a bit first. Your town water has probably got around 50ppm TA so your TA may slowly creep up a little also. Have you tested your town waters TA and pH?

Interesting. So my fill water is TA 140, CH 90 & pH 7.55. Lot of alkalinity in that water.

Pool pH is up to 7.41 this morning, so it is creeping up slowly. Edit that : After properly re-calibrating the pH meter it's still at 7.31 (and fill water is 7.50), so it actually hasn't moved in over a week now. We'll see what happens when I do my weekly "evaporation top up" on Thursday.

 

[AUSpool]

Wow, your TA is high. I initially thought that cant be right bit have a look at the spread of results from the published water quality results; https://www.watercorporation.com.au.../dwq-annual-report-perth-aesthetic-tables.pdf

I was initially thinking maybe you’ve gone too low on your TA and maybe you might benefit from bringing back up to 70ppm and see where your pH sits there. But given your evaporation is for the most greater than rainfall your TA will go up. Wait till you’ve topped up, give it time to mix and see where it sits.

What pH meter are you using and is it one or two point calibrated?
Are you going to test borates with the guess strips (OK in this case) or are you going for the Mannitol test?

 

[Brad_C]

What pH meter are you using and is it one or two point calibrated?
Are you going to test borates with the guess strips (OK in this case) or are you going for the Mannitol test?

I'm using an EZDO 6011a. So 0.01 resolution and ~0.05 accuracy (rated at 0.02 but I think that's unrealistic). 2 point calibrated with fresh 4.01 & 7.01 solutions (with certification) from a local chem supplier. The electrode is about 4 years old now, and it's _slow_ but it still calibrates up ok. I have a new electrode on order.

I already have all the gear for borate tests, so it'll be a Mannitol test here. I built a "speedstir" years ago (well before I got serious about pool care) when I needed to do some titration on gypsum samples for a mate.

10kg of Boric acid arrived today, so next task is to knock up a 50ppm test "standard" and practice my tests before I hit the pool.

Yes, I did a "high resolution" 10ppm/drop TA test 3 times on the tap water to make sure I was seeing what I thought I was seeing. It's high. There's also about 1.2ppm FC out of the tap and I can't quite reconcile the high TA with a 7.5 pH, but I did re-check it several times. For that pdf you linked, In theory I'm on the Mirabooka pumping station, but that water comes from several sources throughout the year and I'm not far from Mt Hawthorn and Mt Yokine. All of them are relatively high TA sources.

I've never done a chloride test on the fill water, but those numbers indicate it might be worth doing (for interest anyway).

At this time of the year I lose the best part of 40mm a week to evaporation and rainfall is nil. I must do a volume calculation on that 40mm one day.

 

[yann]

Mate

Been following your thread since I’ve been considering borates too.
My pool ph and ta are much more stable than yours and fill water ta ain’t as high as yours.
I will test with strips.
Anyway couple questions:
Where do you get your boric acid from and how much you paying (I don’t want borax + MA, too complicated)? Poolmath tells me I need 10kg of boric acid to reach 50ppm
What are your main reasons for introducing borates to your pool?

Cheers.

 

[Brad_C]

Where do you get your boric acid from and how much you paying (I don’t want borax + MA, too complicated)? Poolmath tells me I need 10kg of boric acid to reach 50ppm
What are your main reasons for introducing borates to your pool?

Ebay. Seller "ozdingo marketplace". Cost me $70 for 10kg delivered from Qld to WA. That was about half (per kg) what it was going to cost getting it from my regular scientific chem supplier, so I'm ok with that.

I'm trying this for 2 reasons.
- My wife and youngest have bad eczema. I suffered terribly (and chronically) from it until I was in my 20's, and now in my 40's I still have repercussions from the medication. I've read only good things about borates in conjunction with the salinity, so as I can't see a down side I'm going to give it a go.
- Good reports about "feel" of the water, potential improvements in chlorine usage and a bit more "sparkle". None of which really matter above the first point, but what do I have to lose?

The thing is. I have a *little* pool. It's 19,000L. If it turns out I've made a mistake I can just dilute it until its gone.

I've only started on the "troublefree pool" thingo in the last half a year, and so far everything I've done has turned to gold, so I'm willing to give this a bash as we all spend hours in the pool. If it helps with the eczema, then I've won. Frankly if it doesn't cause any adverse effects then I've not lost anything except a hundred odd bucks. That's a cheap gamble.

 

[yann]

Fair enough.

I’ll keep following your progress before I take the plunge if you don’t mind

 

[Brad_C]

I’ll keep following your progress before I take the plunge if you don’t mind

No worries at all. I'm more than happy to be a Guinea pig.

 

[AUSpool]

Your own speedstir, good work.

I found it really hard to find mannitol and used xylitol at first with similar results. I now have a life time supply of both.

I eventually gave in on the pH meter, calibrating it every time was absolutely necessary and a pain. Now its 4-5 drops, white background and I’m done. I use a RedDevil which is the same as an Aussie Gold comparator with the Taylor reagent. But my tap water is at pH 7.2-3 and my pool water never shifts from 7.8.
I would choose to calibrate at 7.0 and 9.1 if you can get it.

I applaud your effort for making a standard but thats a step too far for me, PoolMath says 5400g (I rounded down a little) for 19kL from 0 - 50ppm. I don’t think a 1/3 or 1/4 at a time will move your pH enough to worrie about, it really doesn’t have to be too exact.

 

[yann]

I was thinking the same as Allen, just let your pH come up a bit first. Your town water has probably got around 50ppm TA so your TA may slowly creep up a little also. Have you tested your town waters TA and pH? When you get your boric acid add it in a few stages and monitor your pH in between giving time to let everything come to balance.

In order to maintain boric acid really need a test method, the K2006C, speedstir, mannitol, and some other goodies or the Lamotte borate lest strips. I found these in Aussie at; Borate Archives - Test Strips Online

Hi!
Had a quick look at those borates strips and also noticed phosphates strips https://www.teststripsonline.com.au/product/insta-test-phosphate-low-range/
Are they worth having too? Lots of talks on the forums about phosphates and should levels be ignored?
Sorry slightly off topic but I thought I should ask.

Cheers.

 

[Brad_C]

I eventually gave in on the pH meter, calibrating it every time was absolutely necessary and a pain.

Mine is pretty good. Once a month for calibration is still more accurate than phenol red. If I want it better than a point then I'll calibrate it. I use it for other work also, so calibration is not an issue for me. (edit : I just re-checked and this probe has been in use for 8 years and was manufactured in 2010. Probably why it's a bit slow to respond now).

Had a quick look at those borates strips and also noticed phosphates strips

Yeah, I've wondered about that also. I use my local pool store for phosphates, but I only use starver if I have it handy and feel like it when they recommend it. I honestly don't think it makes much of a difference if you keep the FC levels right. I get a *lot* of pollen in the pool.

I applaud your effort for making a standard but thats a step too far for me

I have the glassware and a +/- 5mg balance, so a standard is pretty easy to knock up. That way I can be confident in my measurement, but yeah not essential.

I found mannitol from a seller on eBay. $10 for 100g. Expensive, but it'll last me a long time. I already had bromothymol blue from an old fish tank, and I have the other reagents (and equivalent NaOH and H2SO4 standards from other work). Heck, +/- 10 ppm would do me fine.

 

[AUSpool]

TFP doesn’t really care much about phosphates, if you maintain your FC then there will be no issue with algae and no need to lower phosphates. Phosphates only come into play when your FC in neglected.

 

[yann]

TFP doesn’t really care much about phosphates, if you maintain your FC then there will be no issue with algae and no need to lower phosphates. Phosphates only come into play when your FC in neglected.

Agreed, but I remember reading somewhere about organic calcification, or phosphate calcification, which could be a problem (stains) to some pools (I think plaster mostly) and in that case controlling phosphate levels would correct the issue.
I agree this is off topic so happy to start a new thread if worth discussing

 

[Brad_C]

I agree this is off topic so happy to start a new thread if worth discussing

Nup. My thread, my rules. Umpire says "game on".

Anyway, phosphates, borates. They both end in "ates".
Due to gross negligence on my part, I have a shed full of phosphate remover, so when the pool store tells me to use it and my filter is due a backwash I use it a couple of days before I backwash.

 

[AUSpool]

Agreed, but I remember reading somewhere about organic calcification, or phosphate calcification, which could be a problem (stains) to some pools (I think plaster mostly) and in that case controlling phosphate levels would correct the issue.
I agree this is off topic so happy to start a new thread if worth discussing

I believe your answer is somewhere in here; Phosphates.....are they worth removing??
I cant recal but think the main impact of calcium phosphate scaling was on the SWG plates with way high phosphates which is not an issue anyway if you have a self cleaning model. Maybe if we ask nicely @JoyfulNoise he may remember more than me.

And for Brad, borates is one of many topics that Joyful excels at but think borates may be a favourite. The recipe for the mannitol test is found in here; New borate drop test at piscines-apollo vs. test strip