Trouble getting CC to zero.

[chem geek]

Your TA is a little on the high side which can lead to a tendency of your pH to rise, though you seem to find it pretty stable. The next time you find your pH too low on opening, if your TA is high then instead of adding Borax, do aeration instead. That will cause the pH to rise with no change in TA. Though Borax doesn't add any carbonates, it will have the TA rise when it makes the pH rise (because they go together). It is only aeration that actually removes carbonates from the pool via carbon dioxide outgassing.

I wouldn't worry too much about the rising pH in SWG pools since keeping the TA low and using Borates does seem to help a lot. Yes, you probably will need to add acid more frequently than you do now, but it won't be as often as with most SWG pools where people don't know about the low TA and use of Borates. Check out the various threads on rising pH in SWG pools to see people's experiences and how much acid they need to add. It might be tolerable for you.

Anyway, it sounds like you've got a pretty nice and easy situation currently, except for dealing with iron in your fill water. You might consider using a water softener filter for the water -- you might even have one already for your house. Also, if you use a pool cover (such as the solar cover you mention), then that will significantly cut down your loss of chlorine during the day, will keep your pool warm at night and I'll bet that it's use is why you don't see much of a pH rise even with the higher TA.

As for BioGuard Mineral Springs, the "Beginnings" added at startup is just salt (sodium chloride), Boron salt (i.e. borates), and acid (inorganic and organic). The "Renewal" is just the same thing but with less salt and more Boron salt (borates) and inorganic acid and a little aluminum salt. In California, the Beginnings is just salt with a small amount of Cyanuric Acid (CYA) while in Renewal there is no Boron salt (borates) in the product and instead there is sodium bisulfate (acid). This dry acid adds sulfates to your water and high levels can cause problems, particularly with plaster (but we don't know exactly how high so generally just try avoiding adding too many sulfates) and I don't know if there are any issues with sulfates and vinyl pools (probably not). We do know that high levels of chloride and sulfates together are corrosive to stainless steel (especially with high chlorine levels).

The only thing in the product that helps with the rise in pH is the Boron Salt (borates). The products still add acid (at least partly to neutralize the borate that is alkaline) that is probably sodium bisulfate even outside of California (what is called "inorganic acid"). California identifies boric acid as a hazardous waste so that's probably why it's not put into the BioGuard products sold in California (it probably requires special labeling and/or handling requirements). If BioGuard were really on the ball, they would recommend a low TA setting with their system. I can't find their MS-10 or MS-20 product manual so don't know what TA they recommend.

You can check the price of the BioGuard Mineral Springs and compare it to the equivalent of adding Borax and dry acid (and salt) that you could purchase separately.

Richard

[duraleigh]

Huskerfan,

I'm a little confused by your CC's? How are you measuring .4 and .6 values? I am not aware of a test that precise.

[chem geek]

Dave,

The FAS-DPD chlorine test can measure Free Chlorine and Combined Chlorine each to 0.2 ppm since using a 25 ml sample size has one drop of titrant measure 0.2 ppm (the 10 ml sample size has one drop measure 0.5 ppm). You add 2 dippers of R-0870 powder which makes the sample turn pink if free chlorine is present, then add R-0871 dropwise until the sample turns colorless. The count of drops is Free Chlorine. Now you add 5 drops of R-0003 and the sample will turn pink if combined chlorine is present, then add R-0871 dropwise until the sample turns colorless. The count of drops (after adding the R-0003) is Combined Chlorine.

Richard

[duraleigh]

Thanks, Richard,

I had fogotten about doing that test with 25ml. Makes perfect sense to me now. (Tho, I'd have to say, that precision seems like a little bit of overkill)

Nevertheless, I understand now.

[huskerfan]

It's definitely overkill if your pool is at shock level! When it's not it doesn't take that much longer or that much more reagent. I was told .4 cc is acceptable, .5 or higher - shock, thus I measured with the 25ml level. LOL - I guessed .6 on my cc now, it was just barely pink after adding one drop of 0871. It actually could have been .7 or up. Sometimes you just gotta guess .

Richard, I was told to only use one dipper of the DPD powder regardless if you were testing using the 25ml line or the 10ml line. Quite possibly I was told wrong, but it was from a very reliable source. You're absolutely right on the aeriation, but for now we're starting our planting season and didn't have the time to hook up the fountain, and too cold for these bones to jump in! The borax was handy and quick. My TA is a little high, but I read it's ok as long as it stays under 180. It'll drop as we start to swim too --- that's those times when I need a little muratic acid as my daughter is 10 and we have her friends over a lot - so it gets a lot of aeriation!

Will check the chlorine and cc levels once more before going to bed - will let it come down and get my solar blanket on tomorrow. When you fill with iron filled well water you don't want evaporation either.

Matt 4x4 talked about a brown dust algae where he had to overshock to get rid of it... wonder if that's what mine is. I don't think I want to shock over, let alone up to 19 again, as I don't want my iron to fall out.

After my chlorine drops to my normal rate I'll recheck my cc using the 25ml line and repost the actual number. I think I'm just gonna have to live with some cc in our pool. Thanks again!

[chem geek]

The Taylor instructions say to use two scoops and somewhere else on this forum (if I remember correctly) somebody experimented with differing numbers of scoops and some people got slightly different results. With my own testing, I found that it didn't seem to matter at the chlorine levels I was testing, but as a general rule I think it best to follow Taylor's instructions as can be seen at this link for the K-2006 kit.

Your higher TA is perfectly fine since you've got a vinyl pool so can have lower CH (which you have). The only issue with higher TA in your situation is a tendency for the pH to rise, but you don't see that because you keep your pool covered (with a solar cover) and probably don't have aeration features (fountains, waterfalls, etc.). If you had an SWG, then the higher TA would likely cause a very large rise in pH.

Richard

[ivyleager]

FYI,

I just purchased reagents and DPD-FAS powder directly from Taylor, which I would recommend over going thru this site. I received them in 2 days!

Anyway, the scooper for the Taylor powder is TINY! I can see why their directions may state to use 2 scoops. It's MUCH smaller than the one included in the poolsolutions kit.


CaryB