Inroductory post and initial pool opening questions

[rswanson]

Hi forum-
I am brand spanking new to pool ownership, although I’ve been lurking here for a few months to gather information. This is a great site…I love it when I can find this sort of concise information on a forum.

We bought our home last November and the previous owners had installed a 15x30x4 (approx.) oval above ground vinyl lined. My volume estimate is around 10,000 gallons. The pool was, of course, closed and covered when we took ownership. I pulled the cover off this past weekend and was fortunate to be greeted by crystal clear water. After topping up to mid-skimmer level from our well water supply the pool has been uncovered for the past week, untreated and unfiltered as I discovered I needed to order a replacement part for the cartridge filter. Over the past week the water hasn’t shown much in the way of algae growth but I know the clock is ticking. My filter should be up and running tonight and I need to get chemical in the water ASAP.

I bought the 6 way HTH test kit from Walmart so I could perform immediate testing. FC is at 0, as expected. PH appears to be just below readable by the color test…maybe 6.6 or 6.8? I didn’t test for Calcium as it didn’t seem to be consequential at this point, and I haven’t run a CYA test yet.

Alkalinity is where my big question is. When I added the requisite number of drops from the indicator bottle, the sample turned red and did not shift to green. I am interpreting this as TA=0. Is this correct? And, if so, the Pool Calculator page shows I need to add 235 oz by weight (14.6 pounds) of baking soda to my 10,000 gallons to hit a target TA of 100. Does this sound right? And, should I be attacking the low TA before adding any chlorine or attempting to bring up the PH?

Thanks in advance for any assistance!

 

[jblizzle]

Welcome to TFP!!!

You really should test the CYA before you do anything else, as if it is high, you will need to replace water.

You are correct that the TA is likely zero and I get the same weight of baking soda ... although personally I would shoot for about 80ppm (assuming you are planning to use bleach for chlorination). This is the first step after verifying the CYA level is fine. Then raise the pH if required and add chlorine.

 

[Richard320]

Welcome!

You should check CYA. If it's astronomical, you'll be wanting to drain and refill some water, and why treat water only to dump it a day later?

If you have no TA, then, yes, add baking soda. Otherwise when you try adjusting the pH, it will be extremely sensitive and you'll be going back and forth with acid and borax trying to get it to settle down. That sounds like a reasonable amount of baking soda. (Check Costco - they have big bags of it, cheap) It will have a tiny effect on pH. After it's had an hour or so to circulate and mix, recheck pH and TA and adjust pH as needed. Note the TA rise - it can be helpful to back-figure your pool volume.

Then jack the FC up to shock level. Sadly, you haven't said whether the kit you bought is a stopgap until your proper kit arrives or if you intend to use it all year. I hesitate to give any more instructions that you won't be able to follow.

 

[rswanson]

Thanks for the super quick responses! I'll test CYA immediately. If my understanding of pool water chemistry I've gleaned from this site is correct, the previous owners may have chlorinated the heck out of the pool, which could account for the clear pool water upon uncovering? If that's so I might see super high CYA levels as the CYA just sits, correct?

Assuming that's the case, will posting my numbers allow for a determination of how much water to drain, or is this more of a guessing game?

And, I do plan on obtaining one of the more robust testing kits. I bought the HTH 6-way kit so I could get going immediately.

 

[Richard320]

Thanks for the super quick responses! I'll test CYA immediately. If my understanding of pool water chemistry I've gleaned from this site is correct, the previous owners may have chlorinated the heck out of the pool, which could account for the clear pool water upon uncovering? If that's so I might see super high CYA levels as the CYA just sits, correct?

Yep. CYA doesn't evaporate.

Assuming that's the case, will posting my numbers allow for a determination of how much water to drain, or is this more of a guessing game?

Pretty much straightforward arithmetic, since tap water has no CYA. If it reads 100 and you want 50, drain half.

And, I do plan on obtaining one of the more robust testing kits. I bought the HTH 6-way kit so I could get going immediately.

The TF100 has more of the reagents you need than the k-2006, especially the CYA test, which you'll be doing a lot in the beginning. I'd spring for a speedstir, too. No one who owns one regrets the purchase.

 

[jblizzle]

At least that kit actually is drop based and has the CYA test. That is the first step and if previous owners used a LOT of pucks, then you are right, the CYA may be way too high. The CYA will lower 1-to-1 with water replacement. Replace 20% of the water, CYA drops 20%, replace 50% of the water, CYA drops 50%.

Hopefully you will not need to go through the shock process and that will be difficult without the FAS-DPD test.

 

[rswanson]

Hopefully you will not need to go through the shock process and that will be difficult without the FAS-DPD test.

You guys are blowing me away with how quick you respond. Thanks again!

So I may need to go through the shock process due to....? Not being able to maintain acceptable cholorine levels? Or to counteract something yet to happen, like algae bloom?

I'll take the TF100 recommendation to heart and look into the speedstir as well.

 

[jblizzle]

The shock process is needed if your water is not clear, you see algae, you have high CC, or you have higher than normal FC loss at night.

Sounds like your water is clear, but by Performing the Overnight Chlorine Loss Test you would KNOW if there was anything in the pool that would require the shock process.

 

[rswanson]

Ok, here is where i am at. I tested CYA using the HTH and levels appear to be pretty low...in the 30 range. As Im sure you know, the test isnt super accurate so its a bit of a guess but I felt comfortable enough with the water in the pool that I proceeded wiith adding chlorine. I added a full 120oz jug of 8.25% bleach which brought my FC up over what the test kit can measure. I estimate it to be in the 12-14 range? I measured the level after dark, then again this morning and it looks like FC levels are still over what my kit can register.

So whats next? PH is still below 6.6 and TA is still 0 Id assume. Should I be adding baking soda to bring up TA? Towhat target number? Then work on PH, correct?

Thanks again....boy theres a lot to learn here!

 

[jblizzle]

Hard to say by what you posted if you passed the OCLT or not ... thus the need for the FAS-DPD test.

Raise the TA up to 80-90, verify abd then adjust the pH into the 7s if required.