Newbie to this

[Chrisjm15]

Hey everyone,
Just went to the pool shop for the first time and had the water testing done.
$200 for minerals so I thought I'd give this forum a spin!

I have a Magna pool which we inherited when we bought the house.
I believe the Magna is supposed to be relatively easy to maintain?

1st question, is there a cheaper way to buy the magnesium/sodium bags that go in the pool?
$200 for 4 bags seems pretty steep!


Thanks everyone, Chris

 

[PoolStored]

Got to get the attention of some of your mates - @mgtfp @aussieta @AUSpool to help you with solutions in AU...

 

[AUSpool]

Geday Chris and welcome to TFP.

Unfortunately you’ve found your way onto the fluidra gravy train. The Magna pool mineral/magnesium system is the odd one out, it pretends to be better by having no sodium. It is a blend of potassium chloride and magnesium chloride. Both are salts just like sodium chloride. They have rebadged their chlorinator as an hydroxinator but it is essentially a salt water chlorinated system. It uses the chloride in the potassium and magnesium chloride salts to make chlorine. The potassium and magnesium ions are innocent bystanders but unfortunately sodium is much better suited to swimming pools and is a lot more innocent than the other two. There is a lot of smoke and mirrors and fancy advertising in the magnesium salt market, at the end of the day the bags of salt are around 10x the price of the regular. They are also only 98% pure while the regular salts are 99.4% and the impurities have a greater chance containing iron which can cause staining.

I would just use regular salt. It’s cheaper and better.

At TFP we encourage self testing with a quality test kit and taking control of pool management ourselves. The bet kit in AU is the Taylor K2006 from misterpoolman or a kit from clear choice labs. The noticeable difference with these kits is the quality of the reagents and the FAS/DPD free chlorine (FC) test. With a concrete/pebble/plaster pool the calcium hardness (CH) value is important but magnesium interferes with CH test.

What did they say your magnesium and salt levels were?

Magnesium salts are normally sold in 10kg bags while the regular comes in 20kg bags so your 4 mags of fancy salt = 2 bags of the regular.

 

[Chrisjm15]

Thanks for such a comprehensive response!
Yes, definitely want to start learning this stuff.
Really don't like the idea of relying on someone who stands to benefit from my ignorance!

That being said, the guys in the shop are super helpful and have been very generous with their time to explain the different parts that I should maintain myself so that I don't need to call a guy.

Magnesium hardness was 185 ppm and salinity 1,426.
According to the manual, the MH should be between 1-200 and the Salinity around 4k.
For reference, pool size is 45k Ls

The pH needed decreasing too, fortunately I already had some hydrochloric acid, so measured and added.

I'm assuming the Salinity is what the system then uses to generate the chlorine? (The chlorine was fine apparently - 1.37).

 

[AUSpool]

A salinity of 1400ppm . A salinity of ~1400ppm (rounded to the nearest 100) should have set alarm bells off. To bring that up to 4000ppm in a 45kL pool you’ll need 6bags of regular salt ( ~115kg). The Magna pool minerals manual says you need 12bags (~120kg).

I’ve normally seen 800-1200ppm given as magnesium levels. There is no Australian standard for magnesium in the current AU standard for domestic pool water quality. It’s a new industry thing and every company have there own preferred levels.

The pH will normally rise in a chlorinated pool. It will slow at a pH of around 7.8 and total alkalinity (TA) of 70ppm but its best to always keep some pool acid (hydrochloric, HCl) on hand.

A free chlorine of 1.37ppm my be OK from an industry perspective but not for TFP or the old AU standard which says FC should be maintained above 3ppm (for water above 26oC) when stabiliser is used. TFP recommends a FC at around 10% of the stabiliser (CyA), see the FC/CyA chart below. I’ve run at 7/70 (FC/CyA) for almost 15 years. That’s because FC reacts with CyA in a ver rapid equilibrium reaction, something that has never been acknowledged by the industry in general but that is slowly changing.

You’ll have to choose which salt you want to use. You can always go back to magnapool salt if you really want.

 

[AUSpool]

Magnesium hardness was 185 ppm and salinity 1,426.

I would be sceptical of that salinity value. It is very low, almost too low to be possible.
Do you have a low salt or mineral warning on the chlorinator?
Why would the shop recommend less than half the amount needed to get it back in range?
Do they suspect their reading was unusually low?

I would test it again. If it’s still low add a small portion of the salt required (your choice or expensive minerals or normal with less impurities ) and test again before adding more.

I estimated the salt required from the Old PoolMath webpage, the link at the bottom of every page under quick links.

You can use a salt test kit from Clear Choice Labs that detects the chloride ion only.