Confused After SLAM

[ATinyMouse]

Hi Pool Gurus,
I'm a pool newbie looking for some wisdom. After performing my first test with my TF100 kit a few days ago I found testing to be a very straightforward process and being a number guy, I can't stop testing now. I'm so concerned about my FC and CC numbers that I just keep performing tests and end up doing all of them every time. I realize this may be overkill, but tonight will be my third OCLT. After my first one 2 nights ago I believe I had completed SLAM as I had a 0 for CC. The next night I had .5 for CC and I just recorded values for one more OCLT hoping to see 0 again.

After testing my water tonight here are the numbers:

• FC 8 (High end of target FC)
• CC .5 (Pool was used a few hours earlier)
• pH 7.9 (Down from 8.3 this morning, added Clorox pH Down tonight to lower it further overnight)
• TA 240 (Is this bad?)
• CH 200
• CYA 50
• 79 degrees

The TA value has me concerned a bit, but it hasn't moved in the 7 tests I've performed so far and I'm hoping it is related to my attempts at balancing pH. Where I'm really looking for some help is what to do now? My confusion lies with how much bleach I need to know I have to add without having to run the FC/CC test each time or is that what we have to do? Do those of you with pools just get a feel for the amount you add at whatever frequency and if the pool is used by X number of people then you add an extra cup or something? I found the TF100 kit seems to have plenty of chemicals for me to test twice daily for at least a few more weeks, but I'm kinda hoping to not have to do this now and actually start enjoying my pool...

The other thing I'm confused about is that whenever I clean my cartridge (daily, sometimes twice daily) I'm finding living bugs. There's nothing in the pool I've found, but these things are all over the cartridge and I'm guessing they are feasting on the material caught in between the pleats that I can't wash out. Isn't this something chlorine should take care of?

Thanks for any input!

Jason

BTW - The TFP pool app rocks. Happy subscriber here!

 

[Pool Amateur]

I use poolmath to determine how much chlorine to add to get a specific FC or target FC, if you know your pool dimensions you can get an estimated volume of your pool at the Poolmath page, just enter your dimensions and to get even more accurate volume, measure your water level with a tape measure.

Aeration is how you lower TA ( see poolmath), the question is why so high, test the water you use to fill your pool what is the TA of that. If I keep my TA at 70, my ph sits steady at 7.5, if it falls because of rain water or fill water I add baking soda to bring back up, but only 1 or 2 times a season.

 

[ATinyMouse]

I use poolmath to do the clorine add for FC and target FC too. I guess I was more curious about how often pool owners practicing TFP are adding chlorine to their pool. I have a floater with pucks and my FC is staying on the high side, but not changing much. Last night I ran across a thread warning about puck use because of CYA being added, but my CYA hasn't budged in 8 tests after adding stabilizer, so hopefully I have the floater dialed in correctly.

After OCLT here are the results:

• FC 9
• CC 0
• pH 7.7
• TA 220
• CH 300
• CYA 50
• Temp 77

Good idea about testing the hose water. I did that for TA and pH and got:

• TA 260
• pH 7.2

The label on the pH down side warns about not using too much at a time. The TFP app is suggesting I used the last of my 2.5 lbs of pH down, so I'm going to put that in. Hopefully Fleet Farm will have a sale on the stuff and I can stock up. I seem to be using a lot of it.

 

[AftonJeeper]

With your high TA I'd suggest using Muriatic acid to lower pH. More here in recommended chemicals. Fleet farm does carry it but they don't say what the % is. Head over to Menards and pick up this stuff, it's 31%.

 

[domct203]

I use poolmath to do the clorine add for FC and target FC too. I guess I was more curious about how often pool owners practicing TFP are adding chlorine to their pool. I have a floater with pucks and my FC is staying on the high side, but not changing much. Last night I ran across a thread warning about puck use because of CYA being added, but my CYA hasn't budged in 8 tests after adding stabilizer, so hopefully I have the floater dialed in correctly.

After OCLT here are the results:

• FC 9
• CC 0
• pH 7.7
• TA 220
• CH 300
• CYA 50
• Temp 77

Good idea about testing the hose water. I did that for TA and pH and got:

• TA 260
• pH 7.2

The label on the pH down side warns about not using too much at a time. The TFP app is suggesting I used the last of my 2.5 lbs of pH down, so I'm going to put that in. Hopefully Fleet Farm will have a sale on the stuff and I can stock up. I seem to be using a lot of it.

Each 8oz trichlor puck will add about 4ppm to FC and 2.5ppm to CYA in your sized pool regardless of how the floater is 'dialed' in. CYA does not get consumed like FC, and will continue to build up.

Lets say your pool is using about 3ppm a day, or about 5 pucks a week. With continued puck usage, each week you will add 12.5ppm to CYA.

With a starting CYA of 50ppm, in one week your CYA will be at 62.5ppm, in two weeks you will be at 75ppm, in three weeks you will be at almost 90ppm of CYA.

Are you prepared to drain 50% of your pool every three weeks?

 

[Pool Amateur]

I use 12.5% liquid chlorine and pour it in front of return, I test in am & pm and add if necessary, I use between 1-2 quarts depending on Sun conditions and bather load.

Great post by Dom, if you keep using floaters your CYA will rise, if not getting a rise you are not getting accurate test or you are replacing a lot of water.

The other thing I'm confused about is that whenever I clean my cartridge (daily, sometimes twice daily) I'm finding living bugs. There's nothing in the pool I've found, but these things are all over the cartridge and I'm guessing they are feasting on the material caught in between the pleats that I can't wash out.

Sorry I do not know anything about the bugs, but a picture may help someone else identify them.

 

[jeffchap]

Aeration is how you lower TA ( see poolmath), the question is why so high, test the water you use to fill your pool what is the TA of that. If I keep my TA at 70, my ph sits steady at 7.5, if it falls because of rain water or fill water I add baking soda to bring back up, but only 1 or 2 times a season.

I don't mean to sound picky, but I want to chime in because I've seen this misconception posted a couple of times lately.



Acid lowers TA, not aeration. Aeration raises the pH back up to counteract the pH lowering effect of the acid. So it's related, but not exactly as you describe.

How to lower TA

 

[ATinyMouse]

Each 8oz trichlor puck will add about 4ppm to FC and 2.5ppm to CYA in your sized pool regardless of how the floater is 'dialed' in. CYA does not get consumed like FC, and will continue to build up.

Lets say your pool is using about 3ppm a day, or about 5 pucks a week. With continued puck usage, each week you will add 12.5ppm to CYA.

With a starting CYA of 50ppm, in one week your CYA will be at 62.5ppm, in two weeks you will be at 75ppm, in three weeks you will be at almost 90ppm of CYA.

Are you prepared to drain 50% of your pool every three weeks?

Thank you for the numbers! This explains something I am seeing with CYA. This morning when I tested I stopped dropping at around 60ppm, but the subjective nature of this particular test is even commented on the card. I could still see the "dot" at the bottom of the tube until I got to 50, but it was very much obscured at 60. I just pulled my floater and after we use the pool today I'll test for chlorine and perform another OCLT. I understand the problems related to high CYA. I was shooting for 30 when I added stabilizer and ended up much higher than expected. Now I'm thinking I should drain a bit of the water to lower that number.

- - - Updated - - -

With your high TA I'd suggest using Muriatic acid to lower pH. More here in recommended chemicals. Fleet farm does carry it but they don't say what the % is. Head over to Menards and pick up this stuff, it's 31%.

Thank you for the link to Menards! I will check that out. It's 5 times less expensive than the pH down I was using from Clorox too!

 

[AftonJeeper]

While you are there pick up the cheapest strongest chlorine in our area. Menards "Splash" pool shock is 12.5% for just $1.77. I've got a big pool and a garage full of this stuff.

My CYA is 60, I used to use pucks, and it is very manageable as long as you keep your FC up at the minimum for your CYA and understand if algae does attach your going to need more chlorine.

 

[Pool Amateur]

I don't mean to sound picky, but I want to chime in because I've seen this misconception posted a couple of times lately.
Acid lowers TA, not aeration. Aeration raises the pH back up to counteract the pH lowering effect of the acid. So it's related, but not exactly as you describe.

Good catch it is good to be picky as long as your nice and you are absolutely right, thanks for clarifying the info.

 

[ATinyMouse]

While you are there pick up the cheapest strongest chlorine in our area. Menards "Splash" pool shock is 12.5% for just $1.77. I've got a big pool and a garage full of this stuff.

My CYA is 60, I used to use pucks, and it is very manageable as long as you keep your FC up at the minimum for your CYA and understand if algae does attach your going to need more chlorine.

Another link to Menards. I love that place! I'll check it out. The CYA chart is a tab I keep up on my browser for the moment. The TFP App has the recommendations listed as well.