4.5ppm fc loss during day. None at night ?

[obryan2579]

First year pool. I slammed it a couple weeks ago and everything measured out right. Pool is beautiful and crystal clear. My cya was low I thought around 20-25 depending how you look at it. I added a pound of stab 4 days ago and retested today. If I stand with my back to the sun and keeping the vile in my shadow I get 40. If I move it into the sun I can still see the dot. My CC measured 0 everytime. I added 2 quarts 10% bleach to get it back to 7 tonight. I’ll recheck in the morning for loss. The loss is with the pump/filter running.

 

[jblizzle]

Don't trust that your FC is at your target. Make sure you test to confirm if you are trying to report losses.

4.5ppm loss is a little on the high side but within reason. Could bump the CYA a bit more.

 

[obryan2579]

Recheck last night before bed gave me 8fc and this morning was 8 also.

 

[jimim]

I will say when my cya was low my loss was 3 when the water was only 60 and air temp was cool still. My pool is in full day no shade sun.

Once i I raised my cya my loss is 1-2 now. The really low cya does cause I bigger loss.

And im still not at my target cya.

Just be be safe and assume a higher cya for ur fc target so u don’t fall into algae range.

 

[obryan2579]

So is 40cya really low? I’m gun shy to go higher. Would 50-60 be the sweet spot? I just checked and I’ve lost 5 ppm with 1 hour of daylight left to go. It cloudy though. I’m having to dose at a rate of 8 cups of bleach to stay in the 3-7ppm range all day

 

[funandsun]

So is 40cya really low? I’m gun shy to go higher. Would 50-60 be the sweet spot? I just checked and I’ve lost 5 ppm with 1 hour of daylight left to go. It cloudy though. I’m having to dose at a rate of 8 cups of bleach to stay in the 3-7ppm range all day

Lets get some obvious stuff out of the way, reagents are not expired, this is not a pool store CYA test result right?

5ppm in a day for me would be very high, I lose 1.5-2ppm on Sunny days. My personal first thought would be check my CYA test, and assuming everything else was balanced I would throw in a couple of pucks in a floater and check that in 2 days. If you don't have pucks then CYA in a sock is the next move. Can't burn through 5ppm each day all Summer. Something is missing in this equation.

 

[obryan2579]

Tf-100 kits is new. The test are mine. I’ve got a cup of stab in a sock right now in front of a return. I can’t see having to put 8 cups of bleach a day. Somethings up. Maybe I’m off on my CYA measurements. At 40 in the shade of my body the black dot is gone. In the sun I can still see it.

 

[DeanP66]

How's the weather there? If you get a lot of heat during the summer, there's nothing wrong with bumping the CYA to 50. Some people in Texas and Arizona even go up to 60 to save FC from the sun burn off.

 

[obryan2579]

How's the weather there? If you get a lot of heat during the summer, there's nothing wrong with bumping the CYA to 50. Some people in Texas and Arizona even go up to 60 to save FC from the sun burn off.

These losses have come from temps ranging from 70-80 degrees and 8 hrs of sun.

 

[DeanP66]

Personally, I would try upping the CYA to 50 and see how that affects things? Just remember, when you do, your new FC target is 6-8 and never below 4. That's where I keep my pool in San Jose, CA.

Also, try running the CYA test over and over a couple more times with the same water sample. You can pour it back into the dropper bottle and redo the test without using any new reagent. That will give you some practice doing it.

 

[funandsun]

About all you can do then is to increase your CYA and find that balance that works for you. Look at you, your own test kit and thinking through the process of what moves what and makes things happen. Well done obryan!

 

[JesseSchmidt]

Full sun on my pool all day and I run CYA 50 - 60. That helps keep my FC loss to the sun at a minimum.

 

[obryan2579]

I measured CYa today during the 5pm sun. Really bright out. I think I’ve been suffering from newbie cya syndrome. I’m confident I’m at a 35 ppm. Even lower before the other rounds of stab. The bright sun/shadow measurement makes all the difference. Another cup of Stab leeching as we speak. Totally explains the loss. OCLT was zero again last night. I’m confident now.

 

[jblizzle]

It is great having the tools and knowledge to know exactly what's going on in your pool isn't it

 

[funandsun]

I measured CYa today during the 5pm sun. Really bright out. I think I’ve been suffering from newbie cya syndrome. I’m confident I’m at a 35 ppm. Even lower before the other rounds of stab. The bright sun/shadow measurement makes all the difference. Another cup of Stab leeching as we speak. Totally explains the loss. OCLT was zero again last night. I’m confident now.

Well done obryan! Well done.