Numbers translation requested

[woodyp]

Been playing around with the chemicals a bit for the new pool and here's what the pool store came up with:
FC 1.4
TC 1.6
CC .2
PH 7.7
CH 50
CYA 45
TA 177

Their chemical recommendations say to Shock the pool for one thing, when the stuff in pool school says not until it's over .5
They say to add 1.5 gallons of muriatic acid. I don't care what they say on the trichlor since I'm trying BBB.
I punch all those numbers in the calculator, and it tells me to add 26 oz. of muriatic to get to a PH of 7.4 and 74 oz. of bleach to bump FC up to 4. I also used a target level there on the TA of 120.

Is the pool store number on the massive muriatic acid addition trying to bring down my PH.....AND,,,,,,,my TA to 120 or so and will that accomplish fixing the PH and the TA? Why the big difference? Which would you do? Your help is appreciated. Thanks.

 

[JasonLion]

Just completely ignore what the pool store is telling you. The huge amount of muriatic acid is the total amount of acid you need to bring your TA down to whatever it is that they are aiming for. If you added that all at once it would bring the PH way way down and could possibly damage something. What is even funnier is if your PH is low and TA is high. Then they will tell you to add both muriatic acid and soda ash at the same time, both raising and lowering the PH, which serves no purpose other than to get you to spend money.

Your PH, CH, and CYA are all fine where they are. FC is too low. With CYA at 45 you want to keep FC between 4 and 8 and never below 4. Your TA is a little high. The best way to deal with that is to lower PH to 7.2 each time it gets to 7.8. Eventually the TA will come down.

 

[frustratedpoolmom]

The TA is a tad high, but all that usually does it cause the PH to creep up. So, each time the PH hits 7.8, simply calculate the muratic acid dose to lower the PH to 7.2. These acid additions will also slowly lower the TA. There are instructions in pool school for speeding up the Lowering TA Process, but it's not required, unless the PH rise is frequent and annoying, and usually associated with a pool that has water features or an SWG (I don't see these things in your sig so it shouldn't be an issue for you at all.)

So I'd go ahead and lower the PH to 7.2-7.4, and raise your FC to 4 with bleach, and call it a day.

Now as for their advice to shock, how does your water look? And is the FC holding overnight...(what are you testing the water with-are you relying on Pool Store testing?)

A cc of .2 does not indicate shocking required - the presence of green water or algae may indicate otherwise, so might an overnight FC loss.

Ditto Jason - we were typing at the same time. His probably makes better sense.

 

[woodyp]

Thanks guys,

I didn't see any point in trying to lower the TA that fast either. On clarity, the pool looks fine and clear. Just bumped up the chlorine per the Calculator and am now going to drop the PH to the 7.4 with the 26 oz. of acid. I've got test strips and a drops test. Can't get/see clear results with either one. Purely guesstimates looking at those. Even my 19 year old daughter's eyes can't see the difference. Are the TF-100 kits easier to tell color changes on? I"m leaning toward that or one of the digital rascals--Color Q I've been reading on. Gotta do something quick! Is around half up to a gallon about the right amount and normal for this size pool for bleach per day? Just trying to figure out how much to stock on a weekly basis.

 

[frustratedpoolmom]

What is nice about the TF-100 and the Taylor K-2006 is they have the FAS-DPD test kits which are a drop-count based test - meaning you are looking for the water to change from pink to clear, and counting how many drops it takes to get there. So you don't have to compare colors on a chart or anything like that. It also tests FC/CC up to 50ppm which is useful when shocking.

Nothing is more accurate.

As for the amount - our gallonage is similar, but I keep mine covered when not in use - I would say I use 1/2 a gallon of 6% every other day.
Do you have a solar cover? They help cut down on UV loss.

 

[woodyp]

I think I just ordered a TF-100 then!

 

[baudilus]

FYI - the pH test is the same in the TF-100. You'll know for sure if it's too pink (high) or too orange (low), but matching the colours exactly may be difficult. I have a hard time differentiating between the different "in range" colours, but since they are in range I don't worry about it too much.

For chlorine, I find the drops based Taylor kit useless outside of three conditions of chlorine - a lot of it (intense yellow), a little bit (pale yellow), or none (no yellow). It's more of a sanity check for me - "some" chlorine is good enough, most of the time.