Will TSP to lower calcium hardness???

[amanda_easternon]

I've read on a few sites that adding TSP (trisodium phosphate?) will lower the calcium hardness in a swimming pool but I haven't found any clear directions on how to do this.

Has anyone heard about this or tried it?

I have a 16'x32' inground pool (vinyl liner) and it is slightly cloudy (I can't see the bottom drain) and I think it is because of the CH.

I had my water tested today and
Free Chlorine = 0.5 ppm*
Total Chlorine = 0.5ppm*
pH = 7.6
CH = over 490ppm
Alk. = 109ppm
Cyanuric Acid = 5ppm
Copper = 0ppm
Iron = 0ppm

*I added chlorine & stabilizer after testing.

I really don't want to empty the pool and refill it since we are on city water and I don't want my water bill to go through the roof.

Thanks,
Amanda

[duraleigh]

I saw that somewhere, too, and posted that info.

Pooldoc immediately posted back and said, 'DON'T USE IT!". It is apparently an invitation for an algae bloom.

I agree your CH is high but I think your cure may be the Cl and stabilizer you have already started to apply.

You need your own test kit that will test for those things (as well as pH, Alk, and combined chlorine)....don't rely on the inconvenience and unreliabilty of pool store tests.

I'd leave the CH alone for now. If the Cl and increased stabilizer don't ckear it up, post back and you'll get more help.

[amanda_easternon]

Thanks for the info, I do have a good test kit somewhere but we moved in the fall and I'm still trying to find it.

Do you know anything about something called Hydroquest?

Amanda

[cygnusecks]

For the record, when our pool was done, while I was waiting for Ben's kit, I used a Walmart kit. It was broken somehow and my CH always read 0. So I thought I had no calcium, and kept dumping in calcium. Now that I have Ben's kit, I test around 500ppm calcium (CH) but my pool is crystal clear thanks to the other numbers being nearly perfect (again, thanks to Ben's kit). So it IS possible to have clear water with high CH. I'll probably get some scale somewhere in the future but I'm slowly letting the CH come back down through splashout.

Question for all: Does evaporation (and requisite refilling) lower CH? It would seem that it would not lower it, since the CH would not evaporate with the water.

[CarlD]

Re-test and be sure your pool has CC=0.

I don't trust those numbers. I want to see if your cloud is from algae or a high calcium condition.

The chlorine levels seem fishy, as does the total alkalinity.

Is the cloudiness white or some other color, like green, brown or gray?

[amanda_easternon]

I don't really see any color to it. The water looks blue from the liner but I can't see the bottom so I know the water is not nice and clear.

What is CC? (Sorry, I'm not used to all the abreviations for pool stuff.)

Beside the alkalinity it say's "w/stabilizer correction". Does that make any difference?

Amanda

[waterbear]

There are calcium reducers that are sequesterants but have more of an affinity for calcium than other metals. They are based on derivatives of phosphonic acid (as are most of the metal sequesterants) TSP will raise your phosphate levels very high and can provide a lot of algae food. The phosphonic acid derivatives don't seem to do that as much but they can still raise the phosphate levels from what I understand.

[Ozzzz]

waterbear,

Can you provide some product names for those calcium reducing products ? My fill water has about 350-400ppm calcium. This is the 3rd year for the water and with all the evaporation we experience in the Vegas area the CH is over 1000ppm. I am thinking about emptying the pool at the end of this season but if I can reduce calcium before that I might be able to alleviate some of the scaling before then.

[waterbear]

check with your pool store or online seach for calcium hardness reducer. You want a product that is a derivative of phosphonic acid. Many metal sequesterants will also reduce calcium. Read the bottles and see. If you can read the MSDS. That will usualy list phosphonic acid as a component.