Inherited a pond, trying to turn it into a pool!

[PoolDoc]

Live algae clogs DE filters almost instantly -- the solution here is to kill the algae. It will then filter more normally.

If the algae is not dying at 10 ppm, take the levels to 15 ppm, and then 20. You've got to kill the algae, in order for your filter to work.

Ben

[barma16]

It's all starting to make sense, thanks!

[barma16]

OK, so yesterday afternoon I added 8lb Borax, 8.4 gal (6x1.4Gal bottles) 6% Bleach, and 4lb baking soda. I didn't get a chance to test again until this morning, when I had 3ppm Free Chlorine, pH still below 7.0, and 40ppm Total Alkalinity. An hour ago I added another 6 gal 6% bleach, 8lb Borax and 4lb Baking Soda, and will test again in another hour.

Meanwhile I've managed to pick up some 12.5% Sodium Hypochlorite - is it reasonable to assume that 4gal 12.5% is roughly equivalent to 8.4gal 6%, so I should halve the volume to add the same dose?

I'll be testing and dosing every couple of hours today, tomorrow, and probably Monday, hoping for some decent progress!

How can I tell if the algae is dying at 10, 15, 20ppm? Will the water clear, or will dead algae just turn it a different color until it's filtered out?

Thanks!
Mark

[Watermom]

Each gallon of 12.5% should add 2.8ppm, assuming it truly is 12.5%. You never know. Glad you found it. It will mean few empty jugs. You'll be able to tell when the algae is dying as your water will be cloudy and grayish instead of green. Keep working on the pH. Keep us posted how things are going.

[barma16]

When I tested this afternoon the pH was still low, so I've added another 8lb Borax. Total Alkalinity was up to 60ppm, so another 4lb Baking Soda has gone in.

I'm not convinced I'm testing for chlorine properly. When I tested this morning, the first drop of 871 cleared the solution. By the time I'd made a note and was about to start the next test, the solution had regained a slight pink tinge. Assuming that I hadn't measured all of it yet, I kept going.

When I tested this afternoon I was careful to wait a minute or so between drops, and each time the tinge returned. It wasn't much in the way of coloration, but I could see that the drop of 871 was clearer than the solution around it before mixing, so I kept going. I stopped when my FC count got over 15ppm, since I don't think I've added enough bleach to hit that sort of level, especially if the bleach deteriorates in the sunlight.

I retested the chlorine once I'd completed the other tests, and stopped at the point where the returning tinge seemed to be the same color as before. That gave me about 5ppm, which seems more sensible, so I've added 2gal of the 12.5% (which has 12.5% Sodium Hypochlorite listed in the active ingredients, so I'm hoping it's the real deal!).

So my silly question of the afternoon is, just what does "clear" mean in this context? When the solution first clears completely, when it stays clear after mixing, or when (if) it stays clear a minute or so after mixing? I never was much good at chemistry...

[Yeggim]

...So my silly question of the afternoon is, just what does "clear" mean in this context? When the solution first clears completely, when it stays clear after mixing, or when (if) it stays clear a minute or so after mixing? I never was much good at chemistry...

I heard that letting the sample sit after adding the 5 drops of R-0003 reagent to test for combined chlorine it will revert back to pink. When I test for FC with the R-0871 my sample turns completely clear (after so many drops)--even the undissolved crystals of the R-0870 DPD powder. My tests are right on the mark when I test before and after I add a known quantity of bleach according to the Pool Calculator.

May I ask why you wait a minute after each drop of the R-9871 reagent? I add a drop, swirl a second or two and add my next drop and so on. Sometimes I'll add up to 6 drops in rapid succession because I know that I have at least 3ppm in the pool and then swirl. Maybe I'm doing it wrong.

[BigDave]

There are videos on the Taylor website that show FAS-DPD test procedure - might help to see.

[barma16]

May I ask why you wait a minute after each drop of the R-9871 reagent? I add a drop, swirl a second or two and add my next drop and so on. Sometimes I'll add up to 6 drops in rapid succession because I know that I have at least 3ppm in the pool and then swirl. Maybe I'm doing it wrong.

Most likely I'm doing it wrong! I started waiting after I had a sample turn clear, then turn pink again while I was making notes (Just with the 871, still testing for FC). I'm really on day 1.5 of trying to get the hang of this, so I'm learning as I go. I just made an assumption that the pink coming back was a sign I hadn't accounted for all of it. Sounds like my FC is probably much lower than I thought...

[PoolDoc]

Hi Mark;

=> You can assume that you'll need about 1/2 as much 12% bleach as you did 6% bleach.
=> Dead algae is not green. It typically will go from green to grayish green to a greenish gray to bluish gray. The pool is not usually blue till it's clear. Dead algae filters MUCH better than live algae.

[barma16]

Thanks Ben, I think I get that. It's water clarity when testing (specifically for chlorine) that I'm trying to get my arms around now. I don't want to muck up bleach dosage because of bad testing technique.

Appreciate the input (and patience, you must have answered these hundreds of times before!).

Mark