Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: My first foray into pool care - Alkalinity, and others

  1. Back To Top    #1

    My first foray into pool care - Alkalinity, and others

    [Begin long-winded story]
    Well, it seems as though I've been delegated the task of pool care this summer. Since I'm new to the area, I initially just went to the pool store and had them diagnose and prescribe a treatment plan. On today's visit, my test returned the following numbers

    Alkalinity: 30
    pH: 7.2

    Calcium
    Stabilizer: 20
    FC: 1
    TC: 1.13

    This is for a 26,000 gal vinyl pool with a sand filter. Anyway, the alkalinity was of concern, so they prescribed 21 lbs of alkalinity rise, for the low alkalinity, and 5 gallons of hypochlorite to finish off an algae problem. The second part I was ok with, since I wanted to add more anyway, since the shocking from the previous night showed 0 FC the next morning when i tested (I assumed the algae and other organics "ate" it all). But the first part seemed like a ridiculous amount of anything to add to a pool.

    Anyway, so i went over to chemical aisles to pick it up and they only had the smaller sizes which have a much higher unit price (think it was like 6.99 for 5 lbs, and the 20 lb one was only $17.99 or something).

    Anyway, I was a bit reluctant to part with the money, and I had recalled hearing something about using baking soda instead. Looking at the ingredients on the alkalinity rise confirmed it for the most part. Sodium Bicarbonate

    [Beginning of the end of longwinded story and start of actual question]
    So I left with the sodium hypochlorite and headed over to the grocery store and grabbed a bunch of 2 lb boxes of the cheapest stuff they had that listed only Sodium Bicarbonate as ingredient, figured I'd just go home and researching how to dose it myself. It was 2 for $3.00 and was a supermarket brand "Giant".

    Now I had looked at the Arm and Hammer but it was like a $1.39 a lb. So that brings me to my first question. In researching this matter I came across this site.

    Almost every mention of using baking soda, specifies Arm and Hammer baking. soda Does the actual brand matter. Is arm and hammer more pure than the others? I couldn't tell the difference from a box I had in the cabinet and the one's I bought. Anyway the only ingredient it lists is

    Sodium Bicarbonate USP.

    In a list of uses present on the back there is
    "SWIMMING POOL CARE: Baking soda helps stabilize swimming pool pH in the preferred pH of 7.4 to 8.2...."

    So the question is, is this ok to use? And the suggested dosing I read was to do it gradually in 2lbs increments every 4 hours testing pH and alkalinity regularly. Is this correct? Just want to make sure. Also the amount of alkalinity rise prescribed, is that a reasonable number?

    I've also been reading about Bleach as a substitute for pool store bought Sodium Hypochlorite (I know from chemistry that they are one in the same). But i'm worried about possible additives to the bleach. Obviously, I know to stray from fresh mountain scent bleach and what have you, and look for stuff with 5-6% sodium hypochlorite, and like the rest inert. Are all of the bleaches with the latter ok?


    Thank you in advance, and my apologies if this question has been covered before,as an initial search turned up nothing. Still trying to get my feet wet, so to speak (I imagine you'll've heard that one quite a bit).

    Looking forward to learning,
    radne
    Jason
    18X36 IG vinyl 22100 gal. 1.0 HP Hayward Pump w/300# Hayward sand filter.

  2. Back To Top    #2
    Bleach is bleach assuming no fragrances are added. Stay away from colorsafe stuff too. Just plain old bleach, usually the cheapest is best so you should be OK there. As far as the baking soda, again it should all be the same. No reason to stick with Arm and Hammer assuming the ingedient lists just sodium bicarb..
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Yep, I agree with what cruzmisl said! On the bleach, just watch the percentages. Regular ultra bleach is 6%, some of the store brands are only 3% and not as good a deal as they may appear
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4

    Alkalinity results, stabilizer, thermaswim

    Quote Originally Posted by cruzmisl
    Bleach is bleach assuming no fragrances are added. Stay away from colorsafe stuff too. Just plain old bleach, usually the cheapest is best so you should be OK there. As far as the baking soda, again it should all be the same. No reason to stick with Arm and Hammer assuming the ingredient lists just sodium bicarb..
    Yep, I agree with what cruzmisl said! On the bleach, just watch the percentages. Regular ultra bleach is 6%, some of the store brands are only 3% and not as good a deal as they may appear
    Cruzmisl, JasonLion:

    Thank you for the information on the bleach and baking soda. My question seems silly in hindsight, but I just wanted to make sure I had the right stuff.

    JasonLion, your PoolCalculator is amazing. I've learned so much, just by taking the instructions the pool store gives me and running them through the "Effects of Adding chemical section." Learning what all these chemicals do instead of just blindly adding them is great!

    As mentioned above, the pool store reported my alkalinity at 30 initially and prescribed 21 lbs of alkalinity rise. (Using the pool calculator I think they were shooting for ~87 in terms of alkalinity). Anyway I ended up buying 12 lbs of baking soda to start, since I'd be back at the pool store the next day. (It's close by, and since I only have strips, I just take a sample in everyday). Anyway, my dosing procedure was

    6 lbs - premixed in a large bucket, wait 6 hours, test pH and alkalinity with strips, pH was rising but still looked ok, alk still looked low.

    3 lbs - premixed, waited 6 hours, tested pH and alkalinity, pH was rising some, still seemed fine, alkalinity still looked low.

    Added last 3 lbs - pH was getting somewhat higher. Alkalinity still looked low, but not as low as before. Was out of baking soda, and planned on getting the water tested the next day. It rained (Didn't think to fill a jar up and test the rain water). The next day, I gathered my sample (About 16 hours had past since my last baking soda dosing), my alkalinity and pH were 96 and 7.5. Is it possible that the rain could raise the alkalinity this much (Using the calculator 12 lbs would only add ~ 33, not sure about pH as the calculator doesn't give it).

    On another note, my calcium was reported at 317, and the pool guy wanted me to shock with calcium hypochlorite. From reading on here, this adds calcium, which I don't particularly need in a vinyl pool. Asked the guy about it, and he confirmed that it's not really needed in vinyl pools, but it makes the water "crisp" looking and as long as it is under 800 it's fine. Anyway ignored the instructions (Doesn't seem to add too much calcium but, still if I don't exactly need it, why add it) and added a couple 182 oz jugs of bleach instead. It rained once again that night. At this point the water was near the top of my skimmer, drained some water off until it was midway. Took another sample in (yesterday). My results

    Pool Size: 25000, 18x36 Vinyl IG
    Alkalinity: 110

    Again could rain bring this up this much? or is this test error prone? Not sure what type of test kit they use. Behind their counter I see strips (They used this once to test my pH when the phenol red test showed 8.2), a Taylor test kit (Which I've never seen them use), but the kit they seemed to use was a set of like 6 vials, the tops were sealed with foil and labeled (pH,CH,CYA,etc). They'd pierce the foil with a dropper and add the sample, mix it up then place it in some device that gave them a digitial readout.

    pH: 7.6
    CH: 304
    Stabilizer: 10
    FC: .76
    TC: 1.10

    He wanted me to shock once more before adding stabilizer. He suggested dichlor shock since it raises FC as well as CYA. Confirmed this with the PoolCalculator and various threads here,so I added it to the pool, since I could see nothing wrong with it.

    Now regarding adding stabilizer, the paper they give me with test results says

    "CHLORINE STABILIZER: CHLORINE LEVEL MUST BE LESS THAN 1 PPM & WATER MUST BE CLEAR, START WITH CLEAN FILTER ADD 1 LB EVERY 20 MINUTES DIRECTLY TO SKIMMER, IT WILL TAKE 3 TO 4 DAYS TO FULLY DISSOLVE, SO DO NOT CLEAN FILTER DURING THIS TIME"


    Now I've confirmed the underline part from using these forums, but see no mention of the first part. From reading these forums, I'm assuming the bolded part is just to make sure there is no algae present (since adding CYA reduces the effectiveness of the chlorine. However the first part I can't confirm. Is this necessary?

    The last question was about a product that I can't seem to find any information on. It's called Therma-Swim. From looking at the bottle it's Isopropyl alcohol best supposedly creates a thin layer on top of the water surface (I'm assuming this part is true since alcohol floats on water), that supposedly keeps the heat from escaping, effectively causing an increase in water temperature. (Guessing that since the water doesn't drop in temperature at night, it is able to get closer to the ambient temperature during the day). Has anybody ever used this? I don't have a heater, and while I find the temperature to be fine most of the time, some complain it's too cold, so was considering using this if it worked and there were no side effects.

    Anyway, pretty tired of running to the pool store every day for "reliable" results, So I'll be order the TF100 sometime next week, and look forward to doing my own tests. This post is getting rather lengthy so, thank you in advance. This site has been such a wonderful resource.

    radne
    Jason
    18X36 IG vinyl 22100 gal. 1.0 HP Hayward Pump w/300# Hayward sand filter.

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    You can add CYA at any FC level. You can add CYA when you have algae, but if you backwash/clean the filter too soon you will lose most of it.

    I have no ideal on your TA results. It sounds like bad testing.

    Therma-Swim will help just a little. You need to add more frequently and it is no where near as effective as a solid cover.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. Back To Top    #6

    Sustain

    Jason, thanks again. Helpful, as always.

    I got another set of test results from the pool store, when I went to pick up stabilizer

    25,000 gal, 18x36, Vinyl
    Alkalinity: 100
    pH: 7.6
    Calcium: 220
    CYA: 10
    FC: 1.1
    TC: 1.2

    My Stabilizer has been 10 for quite some time, but everytime I go they suggest a different amount of stabilizer. I guess different employees have a different CYA that they target?.

    In the past, the suggested amount to add has been 4 lbs and 5 lbs. Today it was 10 lbs. I went with 4 lbs.

    In previous years, We had used I guess what is called a Sustain chlorination system.

    Consists of 1 application of something called Summer Shield per summer.
    A weekly application of fast dissolving chlorine pellets. [This is the "shock", i guess]
    And has a little container that gets filled with these puck shaped chlorine tabs.

    Unfortunately, the above chemicals have already been purchased for this summer (back in early spring), so I can't really justify switching over to just bleach.

    Now in reading up on the sustain pucks and pellets, (from ingredient list and online), I found out the following.

    1) The active ingredient in both of the products is calcium hypochlorite.

    2) Doesn't contain stabilizer. Was concerned about this initially since the tabs are pucks shaped which from reading is a characteristic of a trichlor tab, which does raise CYA.

    3) On the regular chlorination part, the container has a sliding window to supposedly control chlorine level. Supposedly ranges from 1ppm - 3ppm. This is why I only chose to bring my CYA up to 30.

    From the above and reading these forums. I'm made the following observations/plans

    a) I won't have to worry about CYA getting too high, but I will have to worry about calcium. From reading on here, both require partial draining and refilling to remedy.

    b) With the chlorine tabs, I plan to run the window half open initially, at least until my TF100 arrives, then I will adjust as needed when I see what my actual FC is.

    c) I may or may not need to use the shock "pellets" weekly, depending on my FC vs CC level.


    Do these observations sound correct?

    Thanks again,
    radne (Jason)
    18X36 IG vinyl 22100 gal. 1.0 HP Hayward Pump w/300# Hayward sand filter.

  7. Back To Top    #7
    Guest
    Summer shield is stabilizer

  8. Back To Top    #8
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Yes, that plan sounds reasonable, except that your CH level is likely to be getting quite high by the end of the season. High CH is manageable up to a point but you need to keep your PH from going too high when the CH starts to get high.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •