Thoughts On My Initial Chemistry?

[johig]

I have been reading TFP during the process of building my pool and I purchased the TF-100 before construction was complete. When the pool was handed over to me it had extremely low CYA (about 5 ppm) and low CH (about 110). The Total Alkalinity seemed high, but I believe (from reading on here) that is a bit less critical and the process of changing it requires a bit more effort than some other adjustments. I added calcium and CYA last week. I have made no attempt to change the TA. I tested today and I have these levels (tested with TF-100):
Free Chlorine: 1.5
Combined Chlorine: 0.0
pH: 7.7
Total Alkalinity: 115
Calcium Hardness: 325
CYA: 35
Salt: 5200
Temperature: 53°F
Based on this, I have a few questions:
1. Is the TA anything to worry about?
2. My salt result seems high but the pool store tested it at 3,300 ppm. (a) Are there any common mistakes I could be making with that test? (b) If Salt is really 5,200 ppm do I need to be concerned? (I tested twice, several days apart, with the K-1766 Taylor Salt Test and got very similar results).
3. My SWG turned itself off because of the low temperature, so I am currently using 3" tablets (in a floater) for chlorination. I'm assuming that will continue to raise the CYA, so I am not planning to deliberately add any additional CYA for now. This is just my temporary solution until the temperature increases and the SWG kicks on. (a) Are there any concerns with this approach in general. (b) Do I need to consider adding more CYA (I previously used the granules in a sock method).
Thanks in advance for any input or advice you can provide!

 

[wireform]

I'll let the rest of the crew chime in here in due time. In the mean while assuming your CYA
is 40 which for this time of the year will be fine. Nothing concerns me about your numbers except for the FC which is low by all standards. Forget the pucks in the floater and get some liquid chlorine into the water asap. Check pool math for the exact amount. And lastly stay away from the pool stores testing the water. They are usually off big time in accuracy and advice and will always have something to make you pull your wallet out.

 

[Texas Splash]

Congrats on the new pool and even more so for already having the recommended test kit(s) on-hand.
1 - TA ... nothing to worry about at present. But I would double-check the math next time. You should multiply the # of drops by 10, so your number should be more like 110, 120, 130, etc. The TA should fall slowly over time as you use acid to control the pH.
2 - The salt is a bit elevated, but I don't see an immediate issue requiring water exchange.
3 - I agree that you need to add chlorine ASAP. CA has various sources for liquid chlorine, some of which are refillable stations. But if you chose to simply grab a couple bottles from a hardware store like Home Depot, that will work. So will regular bleach, just make sure it's regular - nothing scented or splashless. With chilly water it will go a long way.

Using the tabs is a personal choice right now. Sure, you need the CYA higher for your SWG when the water warms up, but if you increase it now then your FC needs to be elevated more as a manual pool per the FC/CYA Levels. If it were me, I'd probably just stick with the liquid stuff, then add stabilizer once the water warms-up a bit.

Either way, you're doing well testing yourself. Stick with it and congrats.

 

[johig]

Thanks for the feedback, it is much appreciated. Just to clarify, the TA number was me "splitting the difference" from my test - the color visibly changed at 11 drops and but turned more fully at 12 drops.

As a related/follow up question, what are your opinions on the "super chlorination" feature of the IntelliChlor SWG? I have the IC40 model. Once the SWG kicks on with slightly higher temperatures I know I will need to dial in the SWG percentage to keep things stable day to day. But if I find myself in a similar situation with low FC, is the "super chlorination" a reliable way to correct it in a reasonable timeframe? Or is liquid chlorine still desired in that situation? Thanks!

 

[mknauss]

Or is liquid chlorine still desired in that situation?

Correct. Use liquid chlorine when you need a burst of FC added to your pool.

 

[ajw22]

How many gallons is your pool? Please add it to your signature. It is needed to answer most SWG questions. Also put IC40 in your signature.

 

[johig]

Thanks Allen, that is a good point, sorry! It took me a minute to calculate the volume and adjust for the Baja shelf, benches, and steps, but it's right around 17,000 gallons (pool and spa combined) I just got done noting all the model/part/serial numbers off the equipment. I will update my signature now.

 

[johig]

Correct. Use liquid chlorine when you need a burst of FC added to your pool.

Thanks Marty! I was able to use liquid to get myself out of the very low zone. However, I'm the curious type and decided to experiment with the IntelliChlor a little. I was able to increase FC by somewhere between 0.5 and 1 ppm every hour with the cell at 100%. Is the advantage of the liquid simply that it is quicker (i.e., effectively instant versus a few hours), or is there any other advantage?

To the extent I can rely on the SWG without keeping too much chlorine on hand, that would have some big advantages. It's convenient (especially with wireless control) and it saves the hassle and potential safety concerns with transporting and storing bleach (I have young kids). I also have enough solar power that running the pump and SWG is essentially free. Figuring that it will usually take some time for FC to drift too low, is there a problem with taking a few hours to get it back in check? I figure with the TFP method I will already be testing my pool WAY more frequently and accurately than 99% of pool owners out there. From that standpoint I would probably be able to fix a problem before the average person would even know it existed, even with just using the SWG. Am I missing anything critical with this line of thinking?

 

[ajw22]

Superchlorinate simply sets your IC40 to run at 100% for 24 hours and then it goes back to its previous % setting. It will raise your FC by 10 ppm over a 24 hour period if your pump runs for 24 hours, about 0.4 ppm per hour. Nothing wrong with using the setting to raise your FC over a 24 hour period.

 

[mknauss]

If your FC is just a bit low in your target range and you want to raise it over several hours, then using a higher % setting on the SWCG is OK. But if you find your pool cloudy and/or you just had or are going to have a larger than normal number of swimmers, then the addition of liquid chlorine is much better. You can eliminate the chance of possibly having to do a full out SLAM.

Storage of liquid chlorine is no different than household bleach and other cleaning products. I store mine (a few gallons) in the laundry room cabinet.