Need help with water chemistry!

[jenlov9]

So, our pool is in, PB set up the swg and pump timer to come on for 8hrs a day. We just did our first test, and the chlorine is not even measuring on the test. We are using the TF-100 and Taylor salt water test. Here's the results. We did add water yesterday b/c it was low, but shouldn't it be reading SOMETHING?? Pump has been running since Monday. They put salt in that evening and shocked it (have no idea how much or with what) and run it for 24hrs then set it for 8hrs a day starting around 10am. It is in the mid 90's here during the day. It finished filling last Saturday, and I had to add water yesterday. Pool temp has been about 90 or so. So hot here, and it gets full sun until about 6pm.

Cl- ? too light to even be yellow, really
PH- 8.2
TA- 180
salt- 4200ppm
cya- also reading non-existent. Like, the black dot did not disappear. Could be user error.... but looking down, the black dot is still there, even all the way full. we've done it twice just to be sure we were doing it correctly. huh??


Haven't figured out how to add all the details permanently, but here they are. We are Pentair superflo single speed, Intelliclor 40 swg, pool is I think 24k gallons. It is a lagoon shape vinyl 18x35x29, 3-8' deep.

So, my guess is we need to run the swg and pump much longer to get the chlorine up? Should we add liquid chlorine now or wait and give the swg a chance to bring it up? Bring ph down with acid now or wait on that too? Pool is nice and clear, thankfully.


Tried to include everything I could think of as far as info.
Please help!
Jen

 

[Jimrahbe]

Jen,

The IC40 is a little small for a 24K pool. This is because a cell is rated when running 24/7 at 100% output.

Your cell when running 24/7 and 100% will provide you with 7 ppm of Chlorine. That is .29 ppm per hour.

Since you are only running your pump for 8 hours a day, that is only 2.32 ppm of chlorine per day. With no CYA in your water, 2 or 3 ppm of chlorine will be gone in a heartbeat.

Some things you must do...

1. Get 70 or 80 ppm of CYA in your pool now..

2. Increase your FC by using liquid chlorine or plain bleach now.. A SWCG will NOT add FC quickly... they are very good at maintaining your FC, but if you want to make it happen quickly, you will need to add liquid chlorine.

3. Make sure the output of your cell is set to 100% and run your pump for 12 to 14 hours a day. (This is why we always recommend a VS pump when you have a salt cell..)

4. Always make sure your CYA and FC are in the proper relationship per this chart (Under saltwater).. [FC/CYA][/FC/CYA]

Once you get things somewhat stable you can start reducing your pump run time, so that the salt cell is making the same amount of chlorine as your pool is using each day.

Thanks for posting,

Jim R.

- - - Updated - - -

Also... Use Muriatic Acid to bring your pH down to 7.6 or so. Once you get the FC taken care of... come back and ask about lowering your TA to keep pH in check..

 

[jenlov9]

Jen,

The IC40 is a little small for a 24K pool. This is because a cell is rated when running 24/7 at 100% output.

Your cell when running 24/7 and 100% will provide you with 7 ppm of Chlorine. That is .29 ppm per hour.

Since you are only running your pump for 8 hours a day, that is only 2.32 ppm of chlorine per day. With no CYA in your water, 2 or 3 ppm of chlorine will be gone in a heartbeat.

Some things you must do...

1. Get 70 or 80 ppm of CYA in your pool now..

2. Increase your FC by using liquid chlorine or plain bleach now.. A SWCG will NOT add FC quickly... they are very good at maintaining your FC, but if you want to make it happen quickly, you will need to add liquid chlorine.

3. Make sure the output of your cell is set to 100% and run your pump for 12 to 14 hours a day. (This is why we always recommend a VS pump when you have a salt cell..)

4. Always make sure your CYA and FC are in the proper relationship per this chart (Under saltwater).. [FC/CYA][/FC/CYA]

Once you get things somewhat stable you can start reducing your pump run time, so that the salt cell is making the same amount of chlorine as your pool is using each day.

Thanks for posting,

Jim R.

- - - Updated - - -

Also... Use Muriatic Acid to bring your pH down to 7.6 or so. Once you get the FC taken care of... come back and ask about lowering your TA to keep pH in check..

1. How do I get the cya up? I read in the Pool Math to add a certain amount of stabilizer, but what is this stabilizer and where do we get it?
2. How much bleach? just regular household bleach? anything in particular?

I tried to talk the husband into increasing the swg size and pump, but he was not on board b/c of budget. The PB insisted both were good enough...so he went with that.

We did add the recommended amount of acid (40oz is what the pool math calculator told me) this evening.

Thank you!!!

 

[jenlov9]

The pool math calc is telling me 175oz of bleach or 12oz of Triclor. Does that sound about right? Which is better? And 498oz of liquid stabilizer?? 192oz by weight? that seems like a lot. Is that correct? Should I do liquid or solid?

 

[Jimrahbe]

Jen,

I would only add 8 lbs. of dry CYA (Stabilizer). 128 oz. will increase your CYA by about 40 ppm. It will take a few days to show up in the water, but once it does you can test again and make sure what the level is. Then you can add more if needed. I am not really sure your CYA is zero, so it is better to sneak up on 70... You can buy Stabilizer at Lowes, Home Depot, or on the internet.

Do not just dump it in the skimmer like the instructions say. The best way is to put it in a knee high stocking with the end tied shut. Then put the knee high in the skimmer or dangle it in front of a return with the pump on. It can take a day or more for it to dissolve. It is a good idea to squeeze the sock several times a day.

Just plan bleach with no additives is used, but they recently changed how they make bleach, so in my mind it is much better to find a supplier or pool store in your area that sells Liquid Chlorine that comes in 12.5% gallon jugs. I would try to get your FC up to 5 ppm for now. Assuming your FC is zero, it will take 128 oz. of 12.5% Liquid Chlorine.

Thanks,

Jim R.

 

[jenlov9]

Ok, thanks! Getting all that going now. We ran the pump and swg all night, and the FC has come up a little bit. Ph is starting to come down. Doing CYA and chlorine now.