First ever test - new pool

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kkendall

kkendall

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Aug 29, 2012
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Just got the TF-100 kit yesterday. I took a sample from the pool inside to do the testing.
Results

FC 2.5
CC 0
PH 7.6 (didn't seem as light as 7.5 or as dark as 7.8)
TA 120
CH 120
CYA 20

I'm a total noob with this. Good thing tftestkits.net has videos to reinforce the instructions!
Note - pool finished filling last Saturday afternoon for the first time.

Recommendations?

Thx
 
What has been added to the pool at this point? Did the builder put some CYA in? when?

You are going to want your CYA up closer to 40-50ppm, but depending on when the CYA was added it may not fully register yet.

You CH is remarkably low given our usually hard water.

You will want to keep a close eye on the pH and keep it in range as the new pebble (and slightly high TA) may cause it to drift up.

Also, I would want to make sure you keep the FC above 3ppm at all times until you are certain of the CYA level.
 
I don't know what the builder added....

Pool was filled Saturday afternoon - I knew we weren't going to see anyone until Tuesday because the holiday on Monday, so I just watched the clarity of the water.

Monday morning, it started looking a bit cloudy, so I put in 2 gallons of pool chlorine. Tuesday morning, it looked a little better, then the builder came out and fired up the pump. I see he left an empty gallon jug of pool chlorine, a gallon on muriatic acid (tiny bit gone), and some chlorine tabs. He also left a floater in the pool with some tabs in it. I checked it yesterday and they look like they are 70% gone now.

After testing - and reading the materials in the pool school, I made a note to myself to
* test CH again tomorrow and
* go to the pool store later today to get some solid cynauric acid / stabilizer / conditioner to put in a sock and put it in the skimmer basket

They are supposed to be back next Wednesday to provide the official orientation. I can't wait until Wednesday to start getting the pool water right.
 
kkendall said:
I don't know what the builder added....

Pool was filled Saturday afternoon - I knew we weren't going to see anyone until Tuesday because the holiday on Monday, so I just watched the clarity of the water.

Monday morning, it started looking a bit cloudy, so I put in 2 gallons of pool chlorine. Tuesday morning, it looked a little better, then the builder came out and fired up the pump. I see he left an empty gallon jug of pool chlorine, a gallon on muriatic acid (tiny bit gone), and some chlorine tabs. He also left a floater in the pool with some tabs in it. I checked it yesterday and they look like they are 70% gone now.

After testing - and reading the materials in the pool school, I made a note to myself to
* test CH again tomorrow and
* go to the pool store later today to get some solid cynauric acid / stabilizer / conditioner to put in a sock and put it in the skimmer basket

They are supposed to be back next Wednesday to provide the official orientation. I can't wait until Wednesday to start getting the pool water right.
Click to expand...
Unless the pump is running 24/7, don't put the CYA in the skimmer. Better to suspend it in front of a return, or suspend it from an empty bleach bottle floating in the pool. And shoot low when you add CYA. If you're low, you can add more easy enough, but high CYA is perhaps the most common root cause of problems on the board.
 
Did a test today of the CYA.
FC & pH were the same as before.

Today I tested the CYA "outside" under the patio instead of inside. I think having the bright inside lights to my side allowed me to still see the dot in the bottom of the tube all the way to 20. Outside, with by back to the sun (even though I was in the shade), the dot disappeared completely at about 30.

Learned something today!
 
Worked out a "plan"

FC 2.5
CC 0
pH 7.6
TA 120
CH 120
CYA 30


This is a brand new pebble pool. (Filled 2 weeks)

Note - The pool builder left the pool with pucks in the floater. The problem I have is - I don't know if these are the trichlor pucks or the calcium hypo pucks. They will be back Wednesday to give up the initial orientation on the equipment, etc. I s'pose I can ask then, but it will more than likely be a different guy that will just tell me he doesn't know.

I'd like to know if this is a sound plan....
(been busy reading pool school, etc about the chlorine options)

The plan is - Puck refills will be the calcium hypo type until I get CH to about double. I will supplement with liquid chlor if the cal-hypo pucks aren't quite enough to keep FC up. After CH has about doubled, switch to liquid only.

Make sense?
 
Cal-Hypo ... for pools

Cal-Hypo for pools

Untitled.jpg
 

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duraleigh said:
Have you used these tabs in the past? With the deck chlorinator?
Click to expand...
Nope - this is a brand new pool.
So far it has been two gallons of (10%) liquid to start (within 2 days of being filled) -
then the builder came out and started the pump up, added another gallon and put the floater in the pool. I suspect they may have put a couple in the deck chlorinator, but I can't say for sure since there's nothing in there now.
 
Since those pucks say they "inhibit scale" in spite of them adding calcium to the water, I suspect that part of the other ingredients includes a metal sequestrant. I believe this MSDS is for the product you are showing, assuming that's HTH brand (from Arch Chemicals). It shows the following ingredients (sorted in order):

Calcium hypochlorite ...................... 40-55%
Magenesium sulfate heptahydrate ... 25-35%
Water .............................................. 17-22%
Sodium chloride ................................ 5-15%
Calcium hydroxide ............................ 0-5%
Calcium carbonate ............................ 0-4%
Calcium chloride ............................... 0-4%
Calcium chlorate ............................... 0-4%
Sodium tripolyphosphate ................ 0.9-1.1%

The tripolyphosphate is a strong chelating agent so will help to prevent scaling. The magnesium sulfate heptahydrate helps reduce how much calcium is added, though it will still be at least 7 ppm CH increase for every 10 ppm FC increase. Magnesium sulfate can be problematic since it is one of the worst salts to splash out onto concrete and soft stone surfaces since it has very high salt recrystallization pressure, higher than regular sodium chloride salt.
 
For the sulfates, they are a problem on their own at high levels because they can attack plaster and concrete surfaces, but you have to get pretty high before that's a problem. Even so, we generally tell people to avoid them and is one reason to recommend Muriatic Acid over dry acid or sulfuric acid.

As for polyphosphates, when they break down they will become orthophosphate but we don't care so much about that and HEDP metal sequestrant will also break down to become phosphate. Though phosphate is algae food, if you maintain proper chlorine levels (FC/CYA ratio) you can kill green algae faster than it can grow regardless of phosphate level. That said, there really isn't any reason to add more algae food to the pool unnecessarily.
 
In the past, Cal hypo tabs were intended for septic tanks and pretty much turned to mush after being submerged in water for any length of time.

If you decide to keep these, we will all be interested in their performance.

IMO, tabs are not good to put in skimmers. the super concentration of chlorine and other ingredients when the pump is idle can result in an "overflow" of staining onto the pool walls.

I would not use them but HTH clearly thinks it's fine if you do.
 

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