Woohoo! Test kit arrived in Australia... results are in!

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AdelaidePooler

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Oct 20, 2013
77
Adelaide, Australia
The postman delivered my K-2006C kit today and it came padded out with Sweet Tarts (for my wife... from Indianapolis!) and Reese's cups (for me!).
Having a family mail-forwarder is great!

So I finally got to play with it all and a test this evening yielded the following results:

FC 5.4 (SWG running 8 hours at 50%)
CC 0.2
pH 7.6
TA 90
CH 90 (fill water is 80)
CYA 33 (I knew it would be low, but not zero like the last pool store test I had done!)
Salt (recently bought test strips) 1700 (Pool store that uses Taylor a drop test) 4200

My salt strips do not seem to work very well, the little band at the top doesn't go dark, well only in the middle, and the result after 15 minutes is no where near where it should be. I guess that means they are bad?

So I think my first issue is the CH, then the CYA, then reducing the time/percentage of the SWG a touch.

The pool is covered at the moment with a solar cover, in the height of summer it will be uncovered to let the heat out, right now it's on to try and get some in! High FC probably not doing that any good, according to the manufacturer who recommends no higher than 2-3!)
 
Don't worry about that "high FC". Keep in mind the manufacture suggest that level with ZERO CYA. Your 5ish FC level at 30ish CYA won't harm a thing.
 
Disregard the manufacturers suggestion of 2-3 ppm FC. It is not adequate according to the TFPC methods we teach.

You'll want 3-5 ppm all the time when you get your CYA up around 70 ppm.
 
Thanks Trevs... my wifes wondering which I'm more excited about... my test kit or the actual new arrival (well 6 weeks ago) of our first daughter!
I had the kit sent in a USPS large pre paid box, so it cost the astronomical sum of $78, but those boxes can take up to 20lbs.
The K2006C weighs just over 4 lbs so it couldn't go First Class package, but if it were slightly under 4 lbs, it would be $38.95.
Dave S has told me that the the TF100 XL is 3.7 lbs so that (via a forwarder) would be a good deal.

Still cheaper than buying in Australia for $270!!!

I have found a place that does reagent... but I don't know how much it costs yet. Still may be cheaper to order from the US in plenty of time.


I hadn't considered that the cover manufacturers figures would be sans CYA but I suppose that makes sense as they wouldn't know what levels people were using. I wasn't concerned about it, knowing the suggested levels; and besides, even it did ruin it, the cover's pretty ratty and needs replacing anyway!)
 
So before I added calcium I retested the water, and had my wife do it as well so she gets the hang of it.

FC has jumped to 11.5! (I didn't change the SWG settings from before)
CC is zero
TA still at 90
pH 7.6
CH 90 - I've added 16kg of Calcium carbonate , I will retest.... actually when would be good to retest?
CYA - 6 hrs after the Calcium, I started adding CYA using the sock/return method... That's still underway, and will be for a while!

Could the FC figure be due to leaving the cover on during the day for the last few days and not having the sun on the pool? Seems a big jump. We tested FC twice first using a 10ml sample, and then a 25ml sample so it was completely comparable to the last one I did. Same result.
 
AdelaidePooler said:
Could the FC figure be due to leaving the cover on during the day for the last few days and not having the sun on the pool? Seems a big jump. We tested FC twice first using a 10ml sample, and then a 25ml sample so it was completely comparable to the last one I did. Same result.
Click to expand...

Yep......Keep in mind there's only two things that consume chlorine. Organics and the sun. With the cover on the sun is mostly eliminated, so if there are no organics growing the chlorine will keep building up.
 
Thanks. That will need managing a bit better then. At the moment we are trying to capture the heat, over Christmas we will be trying to let it out!

So on the balancing... (all figures according to PoolMath)

Once the CYA is added (some 2.6kg / 5lbs 12oz of it to bring me to 75ppm ish) my pH is going to drop by 0.73 which would put me at a pH of 6.9.
What effect will this have on my TA? PoolMath suggests it will affect it, but doesn't say by how much.

So should I be trying to aerate to raise the pH instead of using soda ash?
Is that kind of pH change viable with aeration?
I don't have any aeration going on at the moment, and not sure how I would rig it as my return is simply a cut off pipe coming out of the pool wall with no fittings or threads or anything.
Assuming a reasonable amount of aeration how long should I expect it to take?
 

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Whatever it's dissolution rate, I would expect that after it's completely dissolved the pH effect will manifest itself.
It's taken about 24 hrs to dissolve 2kg/4.4lbs, not sure if that's fast or not!

I suppose I'll wait until it's dissolved (I've only put 2kg of the 2.6kg suggested by PoolMath into the sock at the moment) then test again to see how things are coming along, and work out a plan of action from there.
 
AdelaidePooler said:
I suppose I'll wait until it's dissolved (I've only put 2kg of the 2.6kg suggested by PoolMath into the sock at the moment) then test again to see how things are coming along, and work out a plan of action from there.
Click to expand...
I think this is a good plan. I almost never see a significant effect of adding granular cya that requires raising ph, since it dissolves so slowly and ph tends to rise in most pools. In your case, with a TA of 90, I would guess your ph also tends to creep up.
 
Results from this evening:

FC 10
CC 0.5
pH 7.4
TA 90
CH 250 (should I expect this to keep changing after a day?)

I left the cover off all day (been hot and sunny here today) to try and reduce FC, but the pump and thus the SWG (albeit turned down to 30%) were still on to dissolve the CYA. I guess the SWG could be a bit lower.
Didn't test the CYA.
 
Results from this evening:

FC 9
CC 0.4
pH 7.4
TA 90
CH 250
CYA 45

I left the cover off all day again today to try and reduce FC a bit, SWG turned down to 10%... it's still way up there.
According to PoolMath, the 16kg of Calcium I added should have yielded me a CH of around 310, but I'm still only getting 250... will it still be dissolving?

The CYA has started to appear, that was 2kg in a sock, so from that dosing I would expect the level at about 60 eventually. I'll wait for it all to register before adding more.

CC has appeared over the last couple of days, could this be the result of leaves?
 
I would wait a week after you added the cya to test again. If your cya is still low then and your CH is low (CH should show up on test quickly), maybe your pool volume is bigger then you think.

AdelaidePooler said:
CC has appeared over the last couple of days, could this be the result of leaves?
Click to expand...
I would doubt it. Generally we say anything below 0.5 ppm CC is fine, though it appears you are using the 25 ml sample for the fas-dpd test and then it is taking two drops to go clear after adding the R-0003?
 
Yes, I did a 25ml test. The first drop in the CC measurement was very, very, close to clear, so I added another and then it went unquestionably clear.
I did 'swim' for 45 minutes in the afternoon while I was leaf and twig diving (they get stuck in the vacuum head) surely one bather isn't enough to generate that CC?

I've already upped my estimate of volume this season from 48 to 66,000 litres as I finally measured the pool. Oddly, I was previously assuming the real estate agents measurements were right (never trust an estate agent!... apologies if any realtors are members, actually, aren't all realtors members :wink:) it never occurred to me to check it all of last year... turns out they UNDER measured the pool! (And I was being pool stored based on a major underestimation, no wonder it never worked!)

For 16kg of CH to add only 160ppm PoolMath suggests the pool volume would have to be 90,000 litres. It's definitely not that big.

Previously I've ignored a small step recess (would add 700 litres volume) and also the 12" radius at the walls/floor (would reduce 500 litres volume).
Reassessing the average depth profile from 'all slope' to 'shallow plateau - slope - deep plateau' my average depth is 4" or 10cm deeper than I've been using that adds a fairly significant 3,000 litres / 800 US gallons.
Having done that quick bit of geometry, I reckon that would mean I was 3,200 litres (about 5%) low on my estimate, but not 24,000!

Even combining these additions and putting the new volume figure into PoolMath it suggests that the CH should be at 300 rather than 250.

Potential sources of error that remain are:
1. The test results, although I did both the inital one and the latest tests, twice and with different samples so I'm confident in those
2. The amount calcium that's showing up on the test, although I added it 2 days ago, and as linen pointed out it should show up quite quickly, so this is unlikely
3. The amount of calcium I've actually added.

I bought 4x 4kg buckets of calcium chloride from Bunning's (Home Depot equivalent)... PoolMath's results would imply that I only put in 3 out of the 4. But I definitely have 4 empty buckets, so that implies that the buckets were under their stated weight by 25%. That's a fairly major concern, not to mention that, if true, against the law!
I didn't weight it myself before putting it in, (I will in the future) so I don't know whether this is actually the case or not. If I want to put CH in the middle of the range I'm going to need another 4kg of it anyway (actually another 1.3 if there ARE underweight!) so I'll weigh the next one before opening it. The pool water would appear to be fairly well balanced at 250, but my fill water is low CH, and evaporation is significant here when the cover's not on, so I may as well hit the higher level to start with.
 
I weighed the Calcium Chloride before putting it in... 4kg. Exactly what it should be, (bang goes that theory!). I measured CH again 6 hours after addition.
PoolMath would suggest a change of 50ppm CH for a 69kL pool... it went from 250 to 300.

So the volume would appear to be right.
If the weight of the calcium chloride was correct (it's a bit of a stretch to be off by 25%), it implies my initial test was in error, and that I only had a CH of 40 initially, which I can't understand. Counting 9 drops is very different to counting 4.


JUST READ THE EXTENDED TEST DIRECTIONS ON TFP... Turns out I have a 'fading endpoint'
Restesting required.
 

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