Need Salt?

[digit]

I was running my intex saltwater system and it says I needed to add salt. Problem is it is a 16x48 Intex metal frame pool, and I already added 5 bags of salt. I cleaned the saltwater system with vinegar and it says salt level is good than 2 days later I get the low salt error. Been going on for about a week now. I am using city water.

Intex test strip that came with the system

Free Chlorine - tan color that is not on the chart
pH - 8.5
Alkalinity - ~200

not sure if the strips are correct, did two strips and same results

 

[JasonLion]

I suspect you are getting calcium scaling in the SWG, though it is impossible to be sure without either a visual inspection of the cell or a complete set of water test results.

You should never allow the PH to get that high. Keep the PH below 8.0 at all times, and preferably below 7.8. Lowering TA will make that easier. High PH tends to cause calcium scaling, which can cause the SWG to give the error message you mention.

I recommend lowering PH to 7.2 right away, getting a complete set of water test results, and cleaning the cell again.

 

[digit]

Whats the best way to lower the PH?

 

[JasonLion]

Muriatic acid, sold by most hardware stores, is the most cost effective, though it is a little annoying to handle (fumes). The other alternative is dry acid, sold as PH Down and similar names by pool stores. Dry acid costs more, but no handling issues. But muriatic acid is best.

 

[digit]

If I use Muriatic acid do I need to keep the kids out of the pool for 24 hrs?

 

[JasonLion]

No, muriatic acid only needs 30 minutes with the pump running to throughly mix in. For dry acid I would give it an hour to mix in.

 

[digit]

Is there a chart on how much i need to add?

 

[JasonLion]

You can use the Pool Calculator to figure out amounts. Remember that when making very large PH changes it is best to use about 1/2 to 2/3 the recommended amount, give it time to mix in, test again, and adjust further from there, because calculations are never exact for PH changes.

 

[digit]

Got it, going to pick some up today. Is there anything else I should do to the pool? All I have done was get the filter and saltwater system added 5 bags of salt and thats it.

 

[aa62579]

Just a quick note - you must have your TA level plugged into the calculator for it for it to properly calculate the amount of MA needed to reduce your pH. If you use the default value of 100, it won't tell you to add enough.

 

[JasonLion]

What else you need depends on what your other levels are. If you haven't already added some, the most likely thing for you to need is CYA/stabilizer/conditioner/cyanuric acid (lots of names for the same stuff). Stabilizer is only sold by pool stores and the pool departments of some big box stores.

 

[digit]

You mentioned "calcium scaling". I do know when I take it apart to clean it, there is a lot of build up on it. White chalky stuff so I am sure it is. Any ideas on cleaning that up?

 

[JasonLion]

The white crusty chalky stuff is calcium. You can use a dilute solution of muriatic acid to clean it out, try mixing one part of acid into four or five parts of water and soaking the cell plates in that.

 

[digit]

"The cell plates" is that the big piece of metal that looks like a copper bar in the tube?

 

[JasonLion]

No, this is same part Intex tells you to soak in vinegar, a couple of parallel metal plates in the water flow that can be pulled out of the housing.

 

[digit]

Calculator suggested 29oz added 18oz
Tested water again.

Free Chlorine - still does not register on the chart. (I looks like it is closely matches the 0.2 but is a little browner than the test strip picture)
pH - 8.5
Alkalinity - ~200

Water has a green tint to it now

 

[JasonLion]

Having a better test kit would be a huge help.

Did you allow the water to circulate for half an hour with the pump on before testing again? If not, wait the half hour and try again. If you waited, the most likely meaning of the PH still being high is that it was way higher than it said because you had reached the upper limit of the test. If so, you need to add more acid. The risk is that your test strips are bad, and just register high regardless. Intex test strips are not known for reliability.

 

[digit]

Should I take some water and get it test at a pool shop? Is so, how much do they usually charge and how long does it take?

Edit: yes it did circulate for about 30-45 mins

 

[JasonLion]

Most pool stores will test your water for free, hoping you will buy something. Usually it only takes a couple of minutes, but it can be longer if they are busy.

 

[digit]

Nice, I am on my way to get it tested and will post the results (and get some stabilizer)