FC levels and UV

[ryananding]

Hello all! My first post here of TFP so thank you in advance for your wealth of knowledge and help!

A little backstory is that I’ve had a pool servicing company servicing my pool since I put water in it 7 months ago. My kids were complaining of itching, dryness, and not wanting to open their eyes under the water. I decided to spot check the chems on a Thursday (company comes every Friday so it had been 6 days since their last treatment with 0 bather load within the week) and I found the numbers to be wildly unbalanced. Each time they come they send me a report of what the “numbers” are and they seem to have all been punched in arbitrarily. I brought some water to Leslie’s to double check and confirm my suspicion and sure enough, the numbers were off. I came home and got the TA up and pH within normal limits and let the chlorine come down over time. I also bought a Taylor 2005 to further test my chems and have since gotten rid of the service company.

I have a few questions since I’ll be going st this alone and this is my first pool. I have a Pramount UV2 installed on my system. I’ve read that the EPA states that 0.5 ppm FC is all that is needed when running UV. It is full sized 2” so 100% of my pool water passes through the UV system. I also have a Nature2 Fusion with a mineral cartridge installed (just changed last week) and trichlor tabs set to 1. I notice when I load it up with 4 tabs the FC reading hovers around 4-5 ppm so I let it clear out and replaced with 2 tabs this time to see where that puts me.

I alao tested CYA last night and it seems like a ver subjective test. When I saw the dot go away my wife said she could still see it so I added a few more drops. Ended up at around 50. I referred to the FC/CYA chart but am wondering how this all changes since I’m running UV. At my CYA it’s telling me to keep FC at 4-5 ppm. Is there a rule of thumb for chems and running UV? I have zero visible issues with the pool and it’s perfectly clear. I also run a Maytronics dolphin explorer 70 3-4 times a week and have no trees over the pool (see picture).

The first couple pictures are from my initial testing, and then subsequent tests. Also pool and equip pics.

Any recommendations are appreciated!

 

[Texas Splash]

Welcome to TFP! This initial reply may sound slightly painful, but it's no intended to be. Just honest, so here we go:
- Your pool, if an outdoor poor, really never needed UV equipment. Not here in Texas. We get plenty of free UV from the sun.
- The mineral system you are using has copper in it. Copper in the cartridges is never good and when that copper level hits a threshold in teh water, you start to see staining that is extremely difficult to remove. I would remove the mineral cartridges.
- Chlorine (stabilized) tabs are fine for short-term use, but if your CYA is already at 50 I would remove them now and begin a transition to liquid chlorine which has next to no side effects - just good old free chlorine. Add some each day. Maybe down the road invest in a salt water generator for FC production.
- The K--2005 kit is good for now. It has limited reagents, but is good except you are missing a vital part called the FAS-DPD. Get that and you'll essentially makes your K-2005 a K-2006. In the future, consider a TF-100 which is a much better value.
- For proper water sanitation and clarity, stick to the FC/CYA Levels. Burning and itching is often times a sign of poorly chlorinated water, and yours could be that way right now and you wouldn't know if by the eyes (viewing).

Be sure to bookmark our Pool Care Basics page and let us know if you have any other questions. You are 100% correct in taking charge of your water. It's easy and much more reliable.

 

[HermanTX]

I decided to spot check the chems on a Thursday (company comes every Friday so it had been 6 days since their last treatment with 0 bather load within the week) and I found the numbers to be wildly unbalanced. Each time they come they send me a report of what the “numbers” are and they seem to have all been punched in arbitrarily. I brought some water to Leslie’s to double check and confirm my suspicion and sure enough, the numbers were off. I came home and got the TA up and pH within normal limits and let the chlorine come down over time.

This is a common problem with weekly pool service. They try to adjust everything the day they are there but that changes each successive day. If it rains you have that to contend with and if it doesn’t rain you have evaporation and adding fill water so you have that to contend with. It is more of a dump and run and hope it works for 7 days (especially that no algae shows up).

I have a Pramount UV2 installed on my system. I’ve read that the EPA states that 0.5 ppm FC is all that is needed when running UV. It is full sized 2” so 100% of my pool water passes through the UV system. I also have a Nature2 Fusion with a mineral cartridge installed (just changed last week) and trichlor tabs set to 1. I notice when I load it up with 4 tabs the FC reading hovers around 4-5 ppm so I let it clear out and replaced with 2 tabs this time to see where that puts me.

As already stated by @Texas Splash the UV system with copper is not good. It is difficult to follow the TFP methodology and also use your system. We depend on the the CYA/FC chart which adjusts FC based on your level of CYA. This will always be higher then the 1-2ppm required by the UV system. You will need to make a choice on which you wish to follow. The TFP methodology will not give your kids itchy eyes. We have thousands of members that can vouch for that.

I alao tested CYA last night and it seems like a ver subjective test. When I saw the dot go away my wife said she could still see it so I added a few more drops. Ended up at around 50.

There are many of us that use a slightly modified process. Rather than looking down the tube while you are squirting the sample this is my recommendation.
Make your mixture as directed. Then pour it to a set known level that is higher then your current CYA. Let’s say it is 80. Pour to the 80 mark and confirm that you can see the dot. Then pour sufficient mixture to the 70 mark. Then look again. If you see the dot, continue by pouring again to the 60 mark. Do this until you do not see the dot. Then use the mark that you last saw the dot as your CYA. This does 2 things. 1 - you only look in the tube after you pour to the next decade mark so you are not constantly looking at the dot. 2- this maintains that you only report your CYA in decade numbers. You do not want to interpret between the decade lines as it is a logarithm scale, therefore not uniform between the decade numbers.

Good Luck.

 

[Katygreys]

Since we know that the 2 things that consume FC are algae and UV, does it then follow that ryananding’s UV generator is consuming the FC in his pool? Sorry, don’t want to hijack, but just curious.

Also, my family swims in 11ppm FC all the time. No itchy eyes or anything. And zero algae. It’s glorious.

My vote it to ditch the UV, ditch the copper, and use liquid chlorine. TFP keeps my pool crystal clear and enjoyable every day.

Also, get the FAS-DPD FC test. You need it to accurately measure FC. I bought a 2005 a month before I fired my pool guy. Then, the day after I fired him I found TFP. Then, I ordered a 2006C (includes the FAS-DPD test). Others here can give you the TFTest kit number that will “convert” your 2005 into a 2006…

 

[Katygreys]

Ok here it is

FAS/DPD Chlorine Test Kit

tftestkits.net

 

[jeffchap]

UV light is less effective than chlorine for sanitizing water and as Katy states, UV actually breaks down chlorine. So your UV sanitizer is actually doing you more harm than good and that is why we discourage their use.

And the mineral cartridge adds copper to your pool just as many algaecides do. Copper is what turns hair green and stains pool liners, which is why we also discourage its use.

I know it's going to be hard to abandon all this new equipment you just paid for. But 350k users here will all tell you that the TFP method will save you $$$ in the long run. I run my 28k gal saltwater pool all year on about $200 worth of consumables.

 

[pjt]

I have a Paramount UV2 installed on my system.

I also have a Nature2 Fusion with a mineral cartridge installed

trichlor tabs

Those three things are working against you. The UV consumes your FC. The mineral cartridge adds metals to the water. The trichlor tabs are very acidic and add CYA, which quickly rises to an unsustainable level.

There are viable two long-term solutions to chlorinating: SWG or liquid chlorine. You're a great candidate for a SWG.

You have a beautiful pool BTW!

 

[ryananding]

Yikes, super positive replies so far . I'll have to read these and digest this information. I had a DEL AOP 25 and actually got rid of it and replaced it with the UV2 system because I HATED how much air bubbles it pumped into my pool constantly and it was really loud (think rushing bubbles and water through a 3/4" pipe) mounted to the outside wall of my kitchen. This is literally the first pool I've ever owned much less taken care of in my entire life. I trusted the PB to educate me (which they did a poor job of) and they said the UV system was the new way to do things on pools in 2022. I guess I'll can just run the TFP method and ignore the UV light and just reap the benefits while the bulb is still good. Probably won't replace it. Honestly, I haven't had a huge issues with chlorine burning off even in the Texas heat. They shocked my pool so much the FC level remained >9 for a week before hanging around 5-8 for another week and finally dropping to 2-4 and I hadn't even replaced the tabs. Once my Taylor kit read "clear" I finally replaced with 2 tabs and set the Nature2 to the lowest setting (1 on a scale of 6). I'm getting a 1-2ppm reading now. Added chems last night so as of current I am TA 110, pH 7.4, CH 450 (basically live on limestone), FC 2ppm, CYA 50, (haven't tried HermanTX's method above, will do that next go-round).

Thank you all for your prompt responses. I have a lot of homework to do and trial-by-fire, I'm sure. I do have to say, since taking control of the pool care myself, my kids have enjoyed swimming with no complaints. I think it was the off TA (25) and pH (6.5) that was causing issues, not necessarily the elevated FC level mentioned previously.

Let the fun begin!

Ryan

 

[pjt]

ignore the UV light and just reap the benefits while the bulb is still good.

It's a bitter pill to swallow, but the best option is unplugging the UV light. You get plenty of free UV from the yellow dwarf in the sky.

FC 2ppm

Monitor FC carefully. Keep the FC at or above the target at all times, referencing your CYA level: Chlorine / CYA Chart

 

[Bperry]

Yikes, super positive replies so far . I'll have to read these and digest this information. I had a DEL AOP 25 and actually got rid of it and replaced it with the UV2 system because I HATED how much air bubbles it pumped into my pool constantly and it was really loud (think rushing bubbles and water through a 3/4" pipe) mounted to the outside wall of my kitchen. This is literally the first pool I've ever owned much less taken care of in my entire life. I trusted the PB to educate me (which they did a poor job of) and they said the UV system was the new way to do things on pools in 2022. I guess I'll can just run the TFP method and ignore the UV light and just reap the benefits while the bulb is still good. Probably won't replace it. Honestly, I haven't had a huge issues with chlorine burning off even in the Texas heat. They shocked my pool so much the FC level remained >9 for a week before hanging around 5-8 for another week and finally dropping to 2-4 and I hadn't even replaced the tabs. Once my Taylor kit read "clear" I finally replaced with 2 tabs and set the Nature2 to the lowest setting (1 on a scale of 6). I'm getting a 1-2ppm reading now. Added chems last night so as of current I am TA 110, pH 7.4, CH 450 (basically live on limestone), FC 2ppm, CYA 50, (haven't tried HermanTX's method above, will do that next go-round).

Thank you all for your prompt responses. I have a lot of homework to do and trial-by-fire, I'm sure. I do have to say, since taking control of the pool care myself, my kids have enjoyed swimming with no complaints. I think it was the off TA (25) and pH (6.5) that was causing issues, not necessarily the elevated FC level mentioned previously.

Let the fun begin!

Ryan

Letting your chlorine drop to 2 is going to cause you issues since normal sanitary pools consume 2-4ppm of chlorine per DAY. Yes, the pool store and lots of online stuff says the world will end if it ever goes above 4ppm, but that’s just not true if you have stabilizer in the water. If you’re still using those pucks, your CYA will get higher quick and so you’de be better off maintaining it at 6+.

You’de be wise to shut off the UV (which degrades what little chlorine you do have in the water even faster) and take the mineral cartridge out of the frog system. I had one and even my pool guy told me they weren’t helpful so I had them remove it.

 

[reggiehammond]

Yikes, super positive replies so far . I'll have to read these and digest this information. I had a DEL AOP 25 and actually got rid of it and replaced it with the UV2 system because I HATED how much air bubbles it pumped into my pool constantly and it was really loud (think rushing bubbles and water through a 3/4" pipe) mounted to the outside wall of my kitchen. This is literally the first pool I've ever owned much less taken care of in my entire life. I trusted the PB to educate me (which they did a poor job of) and they said the UV system was the new way to do things on pools in 2022. I guess I'll can just run the TFP method and ignore the UV light and just reap the benefits while the bulb is still good. Probably won't replace it. Honestly, I haven't had a huge issues with chlorine burning off even in the Texas heat. They shocked my pool so much the FC level remained >9 for a week before hanging around 5-8 for another week and finally dropping to 2-4 and I hadn't even replaced the tabs. Once my Taylor kit read "clear" I finally replaced with 2 tabs and set the Nature2 to the lowest setting (1 on a scale of 6). I'm getting a 1-2ppm reading now. Added chems last night so as of current I am TA 110, pH 7.4, CH 450 (basically live on limestone), FC 2ppm, CYA 50, (haven't tried HermanTX's method above, will do that next go-round).

Thank you all for your prompt responses. I have a lot of homework to do and trial-by-fire, I'm sure. I do have to say, since taking control of the pool care myself, my kids have enjoyed swimming with no complaints. I think it was the off TA (25) and pH (6.5) that was causing issues, not necessarily the elevated FC level mentioned previously.

Let the fun begin!

Ryan

With all due respect, it sounds like you’ve missed the bus that everyone is encouraging you to jump on.

Using UV and Mineral, running low FC… you’re going to end up in a bad situation very quickly. Either algae or staining - or both. Staining can be basically permanent from copper.

In Texas, a salt water chlorine generator is absolutely a winner. Rip out the UV and mineral as fast as you can and join the SWCG community.

I beg you.

 

[ryananding]

Ok Im going to cut the mineral bottom off of the cap so I can seal the mineral side of the nature 2 (I guess they don’t sell dummy cartridges?) and bought some liquid chlorine today. UV is hardwired so I just lowered my pump to 2000rpm which was low enough to not kick the unit on.

 

[pjt]

UV is hardwired

Can you disconnect the cable supplying power or open the circuit breaker?