Is testing Alkalinity necessary

[maanoi]

So I've just moved into a new place with a pool and it's my job to take care of it.

I've bought a testing kit which tests the ph and chlorine levels. I also bought some chlorine and soda ash.

I did my first test and both the chlorine and ph were low. The ph was 6.8 and chlorine around 0.2

I have since got the chlorine up to ok levels, actually it's maybe a little high but I don't think anything to worry about and with all the rain I guess it will come down very fast yes?

However I cannot get the ph up. Over the last 4 of days I've added 2kg of soda ash, but the ph has not changed at all, it is still reading as the lowest colour on the tester. I actually started to doubt the tester so i put some water in a bucket, added soda ash and then tested it. The tester went a dark purple colour off the charts so I guess the tester is fine.

After searching online it seems that either a low or high alkalinity can make it hard to adjust the ph yes?

So maybe I'm best buying a test kit that also tests alkalinity?

Thoughts, suggestions?

BTW the pool is around 50-55,000 litres.

[fdimike]

I'm not an expert but have successfully maintained our own pool for about 8 years now. It's my understanding that you should first adjust the Total Alkalinity and then your Ph, Chlorine level and then your cyanuric acid level (salt water pool). We have a salt water pool and have had no problems adjusting and balancing things out in this manner.

I hope this helps.

[curtklay]

Alkalinity is crucial to stabilizing the PH. You use sodium bicarbonate to raise the alkalinity to 100-120ppm. After that, check the PH and adjust as needed; soda ash to raise it, acid to lower it. Always check and adjust alkalinity first, or your PH will bounce up and down like a roller coaster. Get a good 4 way test kit that measures free chlorine, total chlorine, PH and alkalinity.

[SantiSuk]

Alkalinity is crucial to stabilizing the PH. You use sodium bicarbonate to raise the alkalinity to 100-120ppm. After that, check the PH and adjust as needed; soda ash to raise it, acid to lower it. Always check and adjust alkalinity first, or your PH will bounce up and down like a roller coaster. Get a good 4 way test kit that measures free chlorine, total chlorine, PH and alkalinity.

But with a salt water pool you also must be able to check cyanauric levels, though I find that once monthly for that particular test is fine, unless you are using chlorine powder purely for its cheap CyA content and/or keeping your CyA level close to minimum levels of 20ppm (CyA levels for a salt water pool drift down slowly and predictably). Salt levels too require pretty regular checking. Crucial to know all the testers you need before going shopping as there is a wide diversity of testers that do anything from one to 20+ tests.

I have never found a tester that just does FC, TC, pH, TA, CyA and salt. I'm pretty sure that you would have to spend around 15,000 baht on a mega test kit (10+) just to cover off those 5 with one single tester/test kit (maybe there is a cheaper non-digital mega kit). So I suspect most of us use combinations of testers to keep testing costs down.

I use a digital tester for FC/TC/TA/CyA, a bottle of pills for TA and a salt digital tester. Unfortunately I had to self-import from falangland (UK) to get the first two of those - Scuba digital colour-comparison tester (about 6,000 baht) and a bottle of TA pills that lasts several years (about 700 baht). The digital tester is not that cheap when it comes to buying replacement reagent tabs though, so I sometimes have the cheapo two-bottle-tubes test kit on hand for routine checks of TC and pH.

The industry would have you believe that (1) you should check everything very regularly like every couple of days and (2) that you need to use a digital tester for accuracy; both are self-serving exhortations IMO.

Others will now come on with more economic solutions no doubt (and flak for my last comment ).

[Chuckles78]

I just bought this from ebay. Good test kit!

[ExpatOilWorker]

Where to purchase an alkalinity test kit in Thailand?

All I can find on Lazada are the standard pH/Chlorine red/yellow test kits.

[Bagwain]

I can supply.

1800 + postage.

Where you situated?

[ExpatOilWorker]

8 minutes ago, Bagwain said:

I can supply.

1800 + postage.

Where you situated?

Koh Tao.

What is the brand of the kit?

How does it look inside?

[Bagwain]

21 minutes ago, ExpatOilWorker said:

Koh Tao.

What is the brand of the kit?

How does it look inside?

Unbranded.

Edited August 29, 2021 by Bagwain

[ExpatOilWorker]

38 minutes ago, Bagwain said:

Unbranded.

Looks about right. New kit, right?

You have a pool company or why are you selling it?

[Bagwain]

18 minutes ago, ExpatOilWorker said:

Looks about right. New kit, right?

You have a pool company or why are you selling it?

I have had a pool building & water filtration business in Thailand for 17 yrs.

Also equipement supplies. Commercial & domestic.

my site www.poolsasean.com