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View Full Version : Pool clarifiers and flocculators Sould I Use Them?



ctbrown
05-15-2011, 11:36 AM
So I just opened my pool (16 x 37ft, ~20K gallons) yesterday and It was the cloudiest that I have ever seen. This is my 2nd year living at this house. The previous year's opening was really easy with the water being very clear. Although last we had a permeable loop-loc cover installed which replaced a tarp.

I tested the water and added bicarb, pH-up and shocked with 4 gallons. Retested water the next day and the results were within spec except for the cloudiness. Been running the sand filter for almost 24hour with no noticeable improvement. I've heard mixed reviews of classifiers and flocculators, nonetheless, I'm really tempted to use them.

Two questions

1) Should I give it wait and see if the filter clears things up or just go ahead and use HTH Clarifier Super Concentrate
2) This is the 1st year with the water permeable cover and I was wondering if the cloudiness was due to that.

Thanks

Chris

CarlD
05-15-2011, 12:10 PM
What does "within spec" mean?
Please post your test results.
This should include
Chlorine level (FC and CC/TC, or just TC if you only have OTO),
pH,
Total Alkalinity,
Calcium or total hardness, and
CYA/Stabilizer.
If you can't get them all then let us see what you can.

Is your pool vinyl or hard sided? Cartridge, DE or Sand filter? Any add-ons? (Chlorinators, mineral erosion, etc).

There should be no reason to add Bicarb and pH-Up at the same time. Bicarb is Sodium Bicarbonate and basically raises Total Alkalinity. pH-Up! is Sodium Carbonate and raises both pH and Total Alkalinity.

BTW, pH-Up! is an expensive version of Arm&Hammer Washing Soda (in the yellow box). Both are Sodium Carbonate. Even the generic version of pH Up is $3/lb. Washing Soda? $.80/lb in my area. Same stuff!
3 bucks vs 80 cents!

BTW, I never use flocculants or clarifiers. Don't need 'em. Generally a skimmer sock and some DE in a sand filter do a better job.

Carl

ctbrown
05-15-2011, 01:13 PM
Pool is 16 x 37ft, ~20K gallons, vinyl sided and sand filtered. The bicarbinate and pH-up were added sequentially, 1st the baking soda to restore the buffering capacity in the morning and then, in the evening, re-tested pH and added recomended ammount per-directions of pH-up and 4 gallons of shock. Re-tested the next day FC and TC are ~3ppm, TA is ~100, pH is 7.4-7.6.

Thanks for the info about the washing soda although I already spent $10 on 5lbs of pH-up. Should I switch to borax instead per BBB method?

I'm not familiar with skimmer socks, but like the idea of something solid that is easily removed, and I have never opened up my sand filter (Hayard ProSeries).

BTW - I am a biochemist and have been in the field for almost 2 decades now. So getting technical is fine and I'll ask the dumb questions as need be.

Thanks

Chris

CarlD
05-15-2011, 03:55 PM
OK, well the buffering is the total alkalinity. When you add baking soda, it goes up. When you add soda ash, it also goes up.
But the problem with T/A is that as the pH rises, so does the measured T/A.
1) Bicarb raise T/A but may raise pH some.
2) Sodium Carb raises pH and T/A, part to do increased T/A, part due to the pH effect on T/A
3) Borax raises pH but the increase in MEASURED T/A is function of the pH rising.

The way I look at it, from a pure pool maint POV, Borax + Baking Soda does the same job as Washing Soda (pH Up!)

Your T/A is now plenty high at 100ppm. You should only raise pH by Borax or aeration (which doesn't raise T/A). However, with a vinyl pool, if you don't add calcium (which you don't need) your T/A won't give you trouble. Right now, mine is "low" at 40 but since my pH is fairly stable, I don't care (vinyl as well).

FC and TC being the same is good--it means CC is 0 and that's what you want.

But, the last key is the stabilizer/CYA level. This alters what the "ideal" FC level is. If your CYA level is between 0 and 30, then an FC of 3 is fine. But if your CYA level is between 30 and 50, you are pushing your luck with your FC at 3. If it's over 50, you are taking a risk with FC at 3. So, your CYA level is the third really important factor:
1) Chlorine level
2) pH
3) CYA level.

Carl

ctbrown
05-15-2011, 05:27 PM
Got it. Need to get accurate CYA level.

Also, once all the numbers that are acceptable, how much time do I need give it to decide whether or not the filter is doing its job?

PoolDoc
05-15-2011, 06:11 PM
You can test it with DE tomorrow!

Add several cups of DE powder to your skimmer with the pump running: if you see it shoot back into the pool, your filter isn't filtering properly.

If it doesn't shoot back, it is filtering . . . though it may be too small or have other problems. But, what water does go through gets filtered.

Ben