Filling New Pool Q's

[RookiePick]

Hi There!

First time pool owner with the below pool due to be handed over from the pool builder in the next 4-7 days.

We have had a few delays with weather and the pool has sat at the first stage ~ half filled for a few weeks and there is green algae forming in several places.

I am thinking that I may well have to basically start out SLAMing the pool to deal with the algae or will normal sanitisation take care of that? Or will the PB deal with this issue as part of the start-up/handover process?

I'm not certain but reading the literature from the PB it kinda looks like they balance the TA, CH, pH, Salt, CYA, get the pool to 3ppm FC and that's that.

In regards to the target numbers at initial balance I think I have a decent handle on what questions to ask them in regards TA, CH and pH targets.

The SWG says it's operating range is 3000-5000ppm with 4000ppm salt preferred. I should ask them to aim for ~4200ppm salt at start up?

The CYA level. I should ask them to leave this in the 20-30ppm range for now but look to increase to the 70-90ppm range recommended for SWG pools when I am sure I have the algae issue in hand? I don't want them to add too much CYA up front as it will make getting the algae killed much more difficult if I understand my reading here the past several days.

My target FC level will depend on the CYA level but also if I am needing to take corrective action off the bat. Should I make sure I have liquid chlorine on hand?

Also any tips for a good test kit in Australia? I'm pretty sure we can't access the ones suggested here and I expect the supplied 4-1 kit will be inadequate to try and manage the pool by TFP principles.

Thanks

 

[ajw22]

Welcome to TFP.

Get your test kit from Clear Choice Labs in Australia...

Testing sample size variation with Clear Choice Labs kits - should be 10ml

Firstly I would like to thank Brett from Clear Choice Labs (CCL) for answering my questions both promptly and honestly. This is excellent customer service and the obvious choice for Australian members for their test kit resources. Whilst the following specifically applies to my personal...

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[AUSpool]

Geday Rookie and welcome to TFP and the forums and congratulations on the new pool,

I suspect the pool builder will shock the pool, make it look clear and bring all the chems up to balanced for hand over. Ask and take a note of everything they add. A shock is not the same as SLAM, the main difference is the specific FC level and the maintain part until you know your finished. See SLAM Process

The 4in1 is not good enough for a SLAM or even general testing but I would suggest the pH comparator is useful to have and use with CCL reagents. It doesn’t have the CyA test, salt or the FAS/DPD. The 4in1 includes TA and CH but the reagents from CCL are much better quality. And to make testing sooo much easier the speed stir is worth its weight in gold.

This is the link to CCL Clear Choice Labs – Simple. Accurate. Fast.

If your inclined I used the ebay salt meter for many years and it held its calibrations really well while pH meters can be a royal pain in the butt. If you go this path you must get it with the specific calibration fluid. Use it’ rinse it and the cap, and then cap it wet and it will last for ages. The best you can expect in terms of measuring is to the nearest 100-200ppm. I would target 4000ppm for your SWG.

Salinity Salt Tester Meter AND Calibration Solution SET for Testing Salt Water | eBay

SALINITY TESTER. Wide range of applications including salt water aquarium supplies and other water salt content testing. Dam, river and bore water quality. Beverage and food processing. Salt Aquarium supplies.

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Get a note book for everything pool related and keep records, it really helps. Use the app or the”Old PoolMath webpage” like below to calculate chem volumes and weights. Kitchen scales are very handy.

Bring up your CyA to 30ppm and SLAM with liquid pool chlorine. After that bring the CyA up to 50 for winter. Once summer starts and you start turning the SWG up bring your CyA up to 70ppm and keep you FC between 5-7ppm and enjoy your pool.

 

[RookiePick]

Thanks @AUSpool. I think keeping a pool notebook makes a lot of sense, I can sketch out the plumbing layout etc while it is fresh in the mind as I will no doubt lose the photos at some point in time! I will make sure I write down what is done to prepare the pool for handover and the starting levels.

The CCL seem to be out of stock for the salt pool kit. They have a freshwater kit available that looks like it is just missing the Salt test (Available separately for ~$50) but I'm unsure if there is any difference in the chemistry? It doesn't appear so from the lack of fresh/salt options in the rest of their kit items. Ah well, I have ordered the kits with a note to cancel the order if the goods aren't suitable for salt pool test.

Cheers!

 

[mgtfp]

Hey Rookie, welcome!

The CCL freshwater kit should be identical to the saltwater kit minus the salt test reagents. Just order the fresh water kit and add the stand-alone salt test kit which seems to be available (not sure why that's available but not the complete salt water kit...).

Which exact SWG do you have? Most Aussie models (like my AstralPool) work in a very wide salt range, they adjust the voltage until the required current for the chosen chlorine production flows. My one says between 3000-5000 is ideal, but it is specified up to 8000ppm. Nothing that can really go too wrong, even if you can't get the salt reagents straight away.

Like AUSpool, I'm also using an electronic salt meter. I use the drop test from time to time, and use the meter more frequently to track relative changes.

 

[RookiePick]

Thanks @mgtfp

The generator is Pool Controls and has a pH dosing module. It looks like the pH dosing is based off the Chlorine generator output + math + manual adjust based on measuring how the unit behaves in practice. There is no pH probe.

All the reading here talks about Muriatic acid for pH control but here in Perth it all seems to be done with HCl. Can anyone enlighten me on the reasoning and if there are any pitfalls to navigate? The Pool Math app doesn't give any option to add HCl from what I have been able to see.
*EDIT* - I see muriatic and hydrochloric are the same thing now. English language FTW!

 

[mknauss]

HCl (Hydrochloric Acid) is muriatic acid. Same thing.

 

[mgtfp]

Thanks @mgtfp

The generator is Pool Controls and has a pH dosing module. It looks like the pH dosing is based off the Chlorine generator output + math + manual adjust based on measuring how the unit behaves in practice. There is no pH probe.

All the reading here talks about Muriatic acid for pH control but here in Perth it all seems to be done with HCl. Can anyone enlighten me on the reasoning and if there are any pitfalls to navigate? The Pool Math app doesn't give any option to add HCl from what I have been able to see.
*EDIT* - I see muriatic and hydrochloric are the same thing now. English language FTW!

As Marty said, same thing.

It's usually labelled here as 33% strength (or 32%-34%). You can still use PoolMath to calculate required amounts based on 31.45% muriatic acid and than scale down the volume by 31.45/33, but the difference is small enough to not worry about it too much.

 

[RookiePick]

Pretty sure the 20L drum from the PB is marked 140g/L (14% w/v) I'll make sure I enquire as to what setting in the controller are appropriate for which concentration at handover.

 

[mgtfp]

I think automatic dosers use more diluted acid, hence the 14%, I guess.

 

[AUSpool]

The Pool Control’s literature says to use a 2:1 dilution which is roughly 14%w/v. Its best to avoid dry acid which adds sulfates. A salt meter and/or TDS meter is really a conductance meter that applies a “best guess” algorithm, most SWG have a basic one of these build in to give you a low salt warning or even a salt level for some. Not sure what the pool controls have but as long as your chlorinator is happy all is good.

The Taylor or CCL salt test is more acurite then my meter. It is a direct measure of the chloride ion (Cl-) but measures to the nearest 200ppm. (1 drop = 200ppm). My meter displays to 1ppm which after a conductivity reading and applied algorithm is an illusion of accuracy which is a trap for all the digital meters we may use. All the tests we use have an error factor of around +/- 10% which is easily close enough for pool testing.

Like @mgtfp I use my salt meter every test tracking change over time rather then an acurite measure of the salt level itself. I do salt, temp, FC and pH most frequently. The salt and temp are useful for CSI, however, fiberglass pools dont need to bother with CSI, its mostly relevant to concrete. I can get a lot of heavy rain on occasion where change over time from the salt meter will indicate if I’ve had significant dilution - time to add salt but also to test my CyA and CH. This is where the record keeping is handy.

The Pool Controls acid system say they use an algorithm rather then a pH probe and hint that FC is the driving force for pH change. I’m sceptical. pH change is mostly driven by CO2 out or off gassing as a result of running elevated TA levels. It would be interesting to see how it works. I would keep records to see how it goes, the amount or acid used and regular pH results from the drop tests. Acid addition will lower TA and add a little salt. There is carbonate alkalinity in the tap water which my come close to offsetting the loss from the acid but I would test and record TA regularly.

 

[RookiePick]

Thanks Steve.

I agree it will be interesting to see how the pH unit behaves in practice. I struggle to see how it has enough data points available to perform anything approaching automation of the pH level. I suspect through monitoring you simply try establish a dosing schedule that gives you a low enough rising pH over time that you have to intervene and dose acid manually at an increased time interval. This will then be subject to changing seasons, movement of other water chemistry parameters, weather events etc.

Regular testing seems to be the best course of action in any event and with record keeping I will be able to "learn" my pool, at least to a certain extent.

 

[AUSpool]

Thanks Steve.

I agree it will be interesting to see how the pH unit behaves in practice. I struggle to see how it has enough data points available to perform anything approaching automation of the pH level. I suspect through monitoring you simply try establish a dosing schedule that gives you a low enough rising pH over time that you have to intervene and dose acid manually at an increased time interval. This will then be subject to changing seasons, movement of other water chemistry parameters, weather events etc.

Regular testing seems to be the best course of action in any event and with record keeping I will be able to "learn" my pool, at least to a certain extent.

Regular testing with record keeping, reading over winter and ask anything your not sure about. You do get used to it quite quickly and regular testing takes a back seat to enjoying and relaxing.

I don’t know if you can change your dosing schedual but you can change your concentration.

By lowering TA you reduce the rate of pH climb which reduces acid demand. With CyA the dependence on maintaining a low pH to maximise hypochlorous acid (HOCl) concentration diminishes. A lot of pools become close to equilibrium with a TA of ~70ppm and a pH of 7.8. I keep my pH @ ~7.8 but it’s constantly moving. When it gets anywhere between 7.8 - 8.0 I dose it back to 7.6. I don’t really use a lot of acid which is why I never bothered with a pH controller. And I didn’t want ORP control because I want to use CyA. With 7ppm FC and 70ppm CyA my HOCl is minimalised buy always just enough + a safe buffer. Something the anti chlorine and CyA side of the fence are constantly striving for but never quite achieve with their alternative solutions that are quick to turn pear shaped.

I just opened a new acid, packaged for Poolworx by Fluidra. 370g/L = 37%. Don’t know if that will be the new norm or if it was a typo, we don’t normally get more for the same $$ value.

 

[mgtfp]

I'd also suggest to run the pool for a while without automated dosing and manual acid additions to fully understand the acid demand of your pool and where the pH ceiling for your setup is. Your pool might be happy to just stay solid at pH 7.8 or 7.9, which is absolutely fine as long as you operate TA and CH in the correct range to balance CSI. But you might never learn how high your pH would actually rise if you keep adding acid.

pH automation can lead to a situation where you get into that see saw where you keep adding acid and than compensate TA drops with baking soda. Once you have to start adding baking soda regularly, you need to review your setup.

 

[RookiePick]

Some good food for thought. I know from my tropical fishkeeping days it was preferable to let the system find it's pH balance and it would be really pretty stable. Constantly trying to hit a number and fiddling with the water seemed counterproductive to me then and fraught with the risk of harming the fish if an error was made.

The mailman has visited, so that is one more thing ticked off the list. CCL have been in touch so hopefully that all gets in the mail tomorrow with any luck.

 

[AUSpool]

Everybody loves new toys. Bob the robot, that is so cool, the’ve even pre selected a nick name for him.

Check your warranty and literature with regards to pH. Although the vast majority of pools tend to decrease in overall chemical demand as the pH reaches 7.8 with TA @ ~70ppm a lot of fibreglass pool manufactures seam to stick with a pH range of 7.2 - 7.4 with TA kept on the high side and this may be enforced in your warranty.

I really don’t understand their reasoning behind maintaining low pH values. TFP’s recomended pH values for fibreglass pools is 7.2 - 8.0 with an ideal range of 7.6 - 7.8. Many years ago I had a fibreglass sail boat bobbing up an down on an ocean mooring. Seawater has a pH of 8.3. Its probably still there totally unaffected by the oceans higher pH values.

When it comes to salt they add the required amount of bags to get it close enough. In 30,000L one 20kg bag of regular salt (99.4%) will raise your salt by 650ppm. Tap water has about 100-200ppm salt to start so if you deduct 100ppm, 6 bags will bring you up to 4000ppm. The PB tried to overdo my salt but they were good about it and left 2 bags with me for latter.

Don’t be tempted by the magnesium spa salts on offer, they are 10X the price and the better quality ones are only 98% pure which adds a greater chance of metal staining. Plus they mess with the calcium test which is not so important for fibreglass but you now need a total hardness and magnesium kit to get calcium. Our tap water comes with natures perfect balance of magnesium anyway.

 

[mgtfp]

a lot of fibreglass pool manufactures seam to stick with a pH range of 7.2 - 7.4 with TA kept on the high side and this may be enforced in your warranty.

I suspect this may go back to the belief that FC turns inefficient at higher pH (which only applies with no CYA in the water). Their thinking might be "high pH -> inefficient FC -> algae -> shocking -> fibre glass dissolving"

 

[RookiePick]

Guys are here now finishing back-filling. Pencil compaction is scheduled for Monday. Hopefully an electrician turns up Monday too...

On the plus side I queried the pool builder to get a better idea of the volume than what I had sketched down in my notes. Pool got 20% bigger and is actually 36000L. I presume that is the total full to the brim volume so water volume will be a few thousand less than that in practice,maybe that is why I jotted down approx. 30kL.

I have the memo on nudging up to the salt value. I think I will have a bit of time to get things right as I will be SLAMing at start up with LC to get the algae eradicated and off to a clean start (hopefully)

 

[RookiePick]

Well the pool is on its way to final fill level.

Pool guys threw in 2 bottles of this unmarked stuff. I'm guessing it's an algaecide? Algaecide + something?

Figured whatever it was it made sense to give it the best chance to work and gave the pool a brush down.

 

[AUSpool]

Interesting, there are no additive type products on their web site. Give them a call if your want, I spoke with them when I was shopping around for equipment and they were very helpful. I suspect it may be a sequestrant to prevent possible staining from the the new water. Something similar was added as part of a startup kit to our pool.

Its a bit late now but I would have been tempted to add bleach from the start of the initial fill and maybe even a floater with tabs To keep on top of any algae from the start.