High CYA, 4.8 FC, No CC

[bdavis17]

Hi all,

New pool owner after purchasing house. Its a large 39k gallon chlorine pool. The pool has been blue and seemingly fine the past month and haven't added any chemicals. The prior homeowner had a weekly pool service come and manage the chemical balance.

I am in Livermore, CA with temps in the 50s/60s.

The owner left a cheap test kit and so I tested the chlorine level and it was extremely yellow/high and upon reading this forum decided to purchase the Taylor 2006K test kit as its more accurate and comprehensive.

I also wanted to test the pool because I have brown/yellow organic stains in the deep end from leaves and worms that are not fading away at all after a month even with brushing and I am told they should.

With the Taylor 2006k test kit I see:

• 4.8ppm free chlorine (25ml sample, 1 drop = 0.2ppm)
• No Combined Chlorine (Adding reagent, the sample didn't turn pink at all)
• CYA was > 100. The 9191 bottle had liquid halfway between the 14ml and 7ml mark and the black dot disappeared before the liquid even hit the 100 mark...close-ish but not there.

My suspicion is that the pool service used the tablets which continue to build up CYA for a long period of time and now I need to potentially drain water to lower it. Pool services must do this it seems as they typically only come weekly in the summer time.

I was surprised that FC was 4.8ppm considering how high CYA is. Curious for any thoughts. Also, it was a little discouraging that I am reading that I will need to add liquid chlorine daily in the summer to the pool to maintain good health and proper CYA levels as that just doesn't seem feasible. Makes me want to convert to saltwater by adding an SWG which is at least a bit less maintenance.

Thanks for the help!

 

[Newdude]

CYA was > 100.

90+ is sketchy and the brain can't read it like we want it to be. Dilute the sample with tap water 50/50. Then add R0013 and double the result. If still 90+, do 2 parts tap, 1 part pool as the 'sample' and triple the result.

4.8ppm free chlorine (25ml sample, 1 drop = 0.2ppm)

Switch to 10ml and each drop is 1/2 FC. There is simply no need for .2 accuracy. I personally don't care about any decimal, only the whole #. A 2.X sucks and a 8.X is great (for most CYA levels.)

Save 2.5X the supplies with 10ml.

Makes me want to convert to saltwater by adding an SWG which is at least a bit less maintenance.

Many of us would fill the pool in if we lost our SWG. I go 2 to 6 weeks at a clip without touching a thing sanitation wise. I test, and am not needed.

It's several times cheaper than Walmart Liquid chlorine in the long run. (the cheapest for most of us) and the convenience of backyard chlorine production with no jug lugging cannot be overstated.

 

[bdavis17]

Thanks will re-do and report back. For CYA will do 3.5ml pool water and 3.5ml tap water and double the end result. At least I learned that a SWG would cost roughly $2,500 + install labor +initial salt which is cheaper than I expected..but here we go..

 

[Lake Placid]

Agree with everything @Newdude has directed you towards. SWG is the way to go and I push all my accounts that direction if they are willing and want to invest in them. There are also other systems if you’d rather deliver LC in a semi automated way, but cost wise I feel SWG is the best bang for the buck.

As far as the organic stains are concerned, if they are organics….run your chlorine at 1/2 to 3/4 of SLAM level for your CYA and they should disappear with brushing and chlorine maintenance at that level.

 

[Newdude]

At least I learned that a SWG would cost roughly $2,500 + install labor +initial salt which is cheaper than I expected..but here we go..

Which unit ? You have a honking pool in sunny CA and the cells are rated for 24/7 runtime. So while a 40k unit may sound perfect for you, it will have to run around the clock in the peak season and might need help if it's a particularly hot season.

Cells have a finite life based upon runtime and the more its 'on' the faster it dies. Bigger cells make the same FC in less time, say a 2x unit only running 12 hours a day, therefore lasting twice as long. You get more life than cost when upgrading. Going 40 to 60k costs about 20% for 50% more lifespan. 60k is as big as they make for residential and the only one I'd consider for your 39k CA pool. (Pentair and Circupool only).

 

[pjt]

For CYA will do 3.5ml pool water and 3.5ml tap water and double the end result.

It's very hard to precisely measure 3.5 ml. You can use your graduated cylinder in your test kit to measure out 25 ml of pool water and 25 ml of tap water, then mix them together. Then, use that mixture to fill to the 7 ml mark and R-0013 to fill to the 14 ml mark. If you don't have a stirring device, you'll want one ASAP.

SWCG is by far the easiest and least expensive way to chlorinate.

 

[bdavis17]

After testing again:

4.5 FC
CYA ~95-100. The 50/50 dilution ended up just above the 50 mark. I stopped when I could no longer see a black dot. Assuming this is pretty bad...

 

[bdavis17]

Which unit ? You have a honking pool in sunny CA and the cells are rated for 24/7 runtime. So while a 40k unit may sound perfect for you, it will have to run around the clock in the peak season and might need help if it's a particularly hot season.

Uh oh, I am hoping for good news here...I saw a 60k unit for $2k-2.5k. Such as this one: Pentair Intellichlor Salt Chlorine Generator | 60,000 Gallon Complete System | IC60KIT

I was thinking with a 60k rated unit I may just need to run the pump for 8 hours per day. I am currently running between 8am - 4pm and if I recall correctly, for 6 hours it runs at like 1800rpm and for 2 hours it runs for 3200rpms. I still need to take the time to calculate and optimize this as I am just adopting what the prior homeowner had set up.

 

[Newdude]

The 50/50 dilution ended up just above the 50 mark.

Ok so it's roughly 120. (Round up to 60, then X2). Its not good, but better than 200+, so there is that.

If you're definitely going SWG, 80 is reasonable CYA in CA so a 1/3 drain would get you to the manageable zone. Always overshoot the estimate because subsequent drains if you missed the target remove new water with the old, becoming less efficient.

With high water table or flooding concerns, consider a no drain water exchange seen here.

Draining - Further Reading

www.troublefreepool.com

I was thinking with a 60k rated unit I may just need to run the pump for 8 hours per day.

An IC60 will make 6.1 FC per 24 hours in 39k gallons. It's won't need to run all day now, or even for some months. But in the peak season, it'll need to run 16 hours a day to match the UV loss.

And that's the one. Or the Circupool RJ-60. With automation, or ever considering automation, you'll want the Pentiar to match your pump. If you'll never automate than either Pentair or Circupool works. Circupool claims they do way better than everyone else, but they do at least as good as everyone else, and maybe better too.

 

[bdavis17]

Ok so it's roughly 120. (Round up to 60, then X2). Its not good, but better than 200+, so there is that.

Sorry, when I said above the 50 mark I meant on the actual vial so its was a little less than 50...lets say 48*2 = 96. But bummer...wasn't expecting this to be as troublesome as I initially thought. Considering the cost of going saltwater is lets say less than $4k (but higher electricity cost), its worth it in terms of less stress.

 

[Newdude]

Sorry, when I said above the 50 mark I meant on the actual vial so its was a little less than 50...lets say 48*2 = 96.

Ok. So we'll call it 100. The diluted test doubles the test error as well so it's not dead on, and just a reasonable ballpark.

So you need to drain/exchange a hard 20% to reach 80 CYA. 25% would make hitting the target more likely, and 30% would be very likely.

Considering the cost of going saltwater is lets say less than $4k, its worth it in terms of less stress.

So I moved and built a 2nd pool. I had my new SWG on-site before I inked the build contract. After having one for 8.5 years, it was *that* high on my wish list that I didn't dare leave it up to the PB during the shortages. Heck. Without the contract he wasn't even my PB yet. I had my ic60 tho. PBs are a dime a dozen.

 

[mknauss]

Welcome to the forum.
Harvest as much rain water over the next month as you can. Drain down the pool by several inches before one of the AR's hit you.

Do you have Pentair automation? Please add to your signature if you do.

 

[Mdragger88]

Be sure you test your ch as well.
You’ll want to be sure to exchange enough water to get it inline as well if its high.

 

[Bperry]

Sorry, when I said above the 50 mark I meant on the actual vial so its was a little less than 50...lets say 48*2 = 96. But bummer...wasn't expecting this to be as troublesome as I initially thought. Considering the cost of going saltwater is lets say less than $4k (but higher electricity cost), its worth it in terms of less stress.

If you’re even remotely handy with basic PVC and electrical work it’s easy to DIY the install, at least it was with the circupool model. I assume most are similar.

 

[bdavis17]

If you’re even remotely handy with basic PVC and electrical work it’s easy to DIY the install, at least it was with the circupool model. I assume most are similar.

I see the Circupool has a 3.1lb power compared to Pentair's 2lb and a longer supposed lifespan so I would prefer that over the Pentair. Is a control panel/center required as well? I can add the SWG to end of the pump system but would need some electrical work to add an additional control panel on the side of the house as the pump is far away and conduit is running underground.

Or do SWGs not require the control panel mounted on the wall as well? A bit confused on that part as the SWG has a built in screen/controls.

Thank you all for the help by the way...this pool has been stressful and glad TFP exists.

 

[Lake Placid]

I see the Circupool has a 3.1lb power compared to Pentair's 2lb and a longer supposed lifespan so I would prefer that over the Pentair. Is a control panel/center required as well? I can add the SWG to end of the pump system but would need some electrical work to add an additional control panel on the side of the house as the pump is far away and conduit is running underground.

Or do SWGs not require the control panel mounted on the wall as well? A bit confused on that part as the SWG has a built in screen/controls.

Thank you all for the help by the way...this pool has been stressful and glad TFP exists.

The IC60 has controls built on it, although it also will tie into pentair automation if you have it or would add it later on. You will need to wire the transformer (the brown box included in the package you linked to) to either 120v or 240v, then the cell plugs in to the transformer. The transformer must be within 6 to 10 feet of the cell as you‘re limited by the cord length on the cell. If you compare costs from other vendors make sure the transformer is included. Most sites list them separately.

 

[Newdude]

+1. And If you're going the Circupool route, they always have a upgrade sale if you buy from them that you buy the RJ-45 (etc) and upgrade for $1-$10. It was $1 recently but even if it goes up, it's a joke. The 'sale' has been going on since I got here in 2019. Lol.

 

[Bperry]

I see the Circupool has a 3.1lb power compared to Pentair's 2lb and a longer supposed lifespan so I would prefer that over the Pentair. Is a control panel/center required as well? I can add the SWG to end of the pump system but would need some electrical work to add an additional control panel on the side of the house as the pump is far away and conduit is running underground.

Or do SWGs not require the control panel mounted on the wall as well? A bit confused on that part as the SWG has a built in screen/controls.

Thank you all for the help by the way...this pool has been stressful and glad TFP exists.

The circupool models do not have any sort of automation or connect to automation. The RJ series has a control box that you mount somewhere on a wall and then the SWCG plugs into that. When you need to adjust the output power, you have to be able to reach that control box to push the buttons.

 

[proavia]

@bdavis17
Do you or don't you have automation?

The SWG and its control box or power center gets mounted at the equipmemt pad.
Post a few pictures of your equipment pad from a few different angles so we can see what you have.

 

[bdavis17]

See attached photos for the equipment. No automation that I am aware of. You can see in one photo that the timers and breaker box are located on the side of the house and they ran electrical underground to the pump.

I also attached a picture of some of the stains. I am assuming at this point that while my FC is on the higher side it is being made less effective due to the high CYA and therefore the stains have stuck around for a long time.