Newbie - Trouble Maintaining FC level?

[aperfcrle]

hey everyone, this is my first post here, but I have been using this site for pool school and the pool math app since I had my pool finished last Fall. I have been trying to get the levels perfect since we opened the first week of May, but I am having some concerns that I cannot keep my FC levels steady. I have been testing almost daily (if not daily, every other day) with the Taylor 2006salt kit, and my FC has been pretty much dropping to .5 - 1ppm frequently no matter what my SWG % is set at. My test results as of yesterday showed FC of almost 6 because I added some liquid chlorine to get the level up again using the CYA/FC chart on here as reference. I just tested it again this evening and I am already down to 4ppm. My CYA is 80, water is super clear, the only thing that is not in "ideal" range is the TA which is 90. At first I was thinking I have some sort of algae even though my water is extremely clear, but my CC is still 0 so I feel like that kind of rules that out?

My other concern is something is wrong with the SWG. I have a Hayward AqauRite S3 for a 15,000 gallon pool and my pool is 13,000 gallons. According to the manual, it produces around .5ppm FC a day. I am running my pump for 12 hours a day, 4 hours at 70% rpm and 8 hours on 45% rpm with the SWG at 60%. I feel like with a CYA of 80, this is plenty of time to produce enough chlorine to keep my level up, but it just keep dropping like a rock. The pool gets full sun all day, but with such a high CYA and the SWG running for 12 hours, I feel like I should not be losing 2ppm FC in less than a day. Any insights would be appreciated!! thank you

 

[PoolStored]

I have some sort of algae even though my water is extremely clear, but my CC is still 0 so I feel like that kind of rules that out?

CC=0 doesn't mean you don't have algae. Do this test tonight...will rule out algae. Link-->Overnight Chlorine Loss Test

Your cell is a bit undersized for your pool, but should/might work. It creates .53lb per day running at 100% for 24 hours. That is 4.9FC in your pool.

At 60%, and 12 hours, it creates 1.5FC in your pool in 24 hours. We are nearing the summer solstice (sun highest in the sky). Common to lose 3-5ppm in June/July.

Add liquid chlorine to get to your FC target and turn the cell up to 100%. That will increase output to 2.4. Increase your run time to 18 hours. At 100% and 18 hours, that will add 3.7FC daily.

Should be close to what you need.

 

[mike6090]

Think of FC as chlorine ready to do work.
What can cause it to do work or be used up?
Just a few of many things…. Pool water temp, urine, any organic matter like skin, hair, dust, pollen, rain, sunlight,

Did you get any of the above? That’s likely where it went. We have cedar and juniper trees that expose with huge clouds of pollen that can wreak havoc on pool chemistry.

This is just my advice but don’t test so much. Swim, relax and enjoy more, test less. You can make yourself nuts over testing. If you got nice clear water and it’s close to optimal then you are good. Don’t chase that last PPM.

 

[aperfcrle]

CC=0 doesn't mean you don't have algae. Do this test tonight...will rule out algae. Link-->Overnight Chlorine Loss Test

Your cell is a bit undersized for your pool, but should/might work. It creates .53lb per day running at 100% for 24 hours. That is 4.9FC in your pool.

At 60%, and 12 hours, it creates 1.5FC in your pool in 24 hours. We are nearing the summer solstice (sun highest in the sky). Common to lose 3-5ppm in June/July.

Add liquid chlorine to get to your FC target and turn the cell up to 100%. That will increase output to 2.4. Increase your run time to 18 hours. At 100% and 18 hours, that will add 3.7FC daily.

Should be close to what you need.

Thank you for the quick response. I had a feeling the cell might be too small. I will adjust to your suggestions and see if it solves it. The pump can be run at any speed for those 18 hours to obtain those results? If so, I will try to drop the rpm little for the extra run time.

 

[aperfcrle]

Think of FC as chlorine ready to do work.
What can cause it to do work or be used up?
Just a few of many things…. Pool water temp, urine, any organic matter like skin, hair, dust, pollen, rain, sunlight,

Did you get any of the above? That’s likely where it went. We have cedar and juniper trees that expose with huge clouds of pollen that can wreak havoc on pool chemistry.

This is just my advice but don’t test so much. Swim, relax and enjoy more, test less. You can make yourself nuts over testing. If you got nice clear water and it’s close to optimal then you are good. Don’t chase that last PPM.

We do have a TON of pollen from oak trees from my neighbors. I am skimming 3 times a day to keep it clear, but some of the pollen goes right through the skimmer so this could also be the case!

 

[DrewLG]

This is just my advice but don’t test so much. Swim, relax and enjoy more, test less. You can make yourself nuts over testing. If you got nice clear water and it’s close to optimal then you are good. Don’t chase that last PPM.

WADR, that's terrible advice for someone who's unsure whether his SWG is working and who hasn't been able to prevent his FC from regularly dropping to nearly 0.

 

[Bperry]

We do have a TON of pollen from oak trees from my neighbors. I am skimming 3 times a day to keep it clear, but some of the pollen goes right through the skimmer so this could also be the case!

In the heat of summer, pools average somewhere around 2-4ppm of chlorine loss per day depending on heat, UV index and probably 10 other things. If your system can make a maximum of 4.9ppm per 24 hours, you may need to run at 100% for close to 24 hours once summer comes. Run it high to start and adjust down as needed.

 

[PoolStored]

Thank you for the quick response. I had a feeling the cell might be too small. I will adjust to your suggestions and see if it solves it. The pump can be run at any speed for those 18 hours to obtain those results? If so, I will try to drop the rpm little for the extra run time.

RPM doesn't matter, as long as you don't get a low flow on the SWCG. Do this. Turn your pump down until your flow light goes off. Increase 200 rpm and run there. That 200rpm is in case your filter gets dirty.