High CC, low FC

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2002sheds

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Apr 15, 2013
173
Beautiful Santa Rosa, CA
Hi,
Long time listener, first time caller...

I recently opened our pool in Northern California. It was neglected over the winter, so it was quite green -- like pea soup. I scraped the bottom, and pulled up gunk, mud, you name it. I read all I could about test kits ( I bought a Taylor test kit, don't remember the model, chemistry, etc. in Pool School, and got started. First, the stats as opened...

Sorry, I will add these to my signature shortly...
18,000 inground, plaster pool. Hayward C-1750 cartridge filter
1+ hp pump
solar panels (currently off-line)

FC = 0
CC= 0
PH = off the charts high
CYA didn't know yet, water way to murky
TA = 100 or so

After scraping and brushing until I saw no color carnage when the brush or net came close to the surface, I started adding chemicals -- namely, 6 or 7 gallons of liquid chlorine (10% strength, 2 packs from Home Depot. I bought the freshest I could fin, which were manufactured a few weeks ago). I also started adding acid, to get the PH down to acceptable range. Along the way, I checked CYA, and it read 40. The water went from pea green to a light green/grey.
I read about the benefits of dichlor and tricolor as shock, and put about 5 pounds in two days ago, along with two more gallons of liquid chlorine. As of yesterday, I was surprised that the FC had dropped dramatically, down to about 4. Meanwhile, the CC seems to be quite high, at around 30 or so at this point. Also alarming is the jump in CYA -- to about 90.
I read a post on TFP from another user with similar issues, and the advice seemed to be to continue to add chlorine, but in liquid form, as to not further add to the CYA. Using the Pool calculator, I found that at this level of CYA I would need to add 5+ gallons of bleach to shock the pool towards killing the remaining algae.
It has been very warm and sunny here in NorCal. Am I close to being on the right track? We have an 8 year old, and he really wants to swim before school starts again :)
I had gone to the pool supply store in past years, and while they were nice, their approach was so cautious that I ended up never getting the pool clear all summer. This year I am trying to figure this out with the help of resources like TFP. Any help will be greatly appreciated!

Thanks,
David
 
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Yes, you're doing some good work so far and you are on the right track.

If FC is below 10 test PH and adjust it to 7.2. PH tests are not valid when FC is above 10.

Yes, use liquid chlorine or concentrated store brand plain 8.25% bleach from your favorite grocery store or big box store. Shock will either add calcium or CYA to your pool depending on what kind of shock it is.

Here is the process for SLAMing - Shock Level And Maintain - your pool. Scoop out as much stuff as you can and it will go much faster. Also brush every day to expose the algae to the chlorine and kill it faster. Keep an eye on your filter and backwash when pressure rises 20-25% above clean pressure.

Come on back with more questions.
 
Hi Pooldv,
Thanks so much. It is easy to feel lost early on. In the old days, (when we had the sand filter that was installed when the pool was built back in the 60's), I would get the water clear enough to vacuum the crud at the bottom to waste. No such practice now, with the drought we have been facing. I replaced the sand filter with a Hayward cartridge filter. Add getting to know it to my learning curve...
I will follow your advice, and re-read the info about how to SLAM. Good to know I am not completely off base.
 
Oops, my bad on the filter. So, the cartridge filter is going to clog up pretty fast as you kill algae. You are going to have to hose off those cartridges pretty often. Every few days probably and some people have had to clean them daily.
 
Hi Pooldv,
Thanks for the advice on the cartridge. I put in a new Pleatco cartridge yesterday, and the pressure read 13 psi. Now it us up to 15 psi.
I am guessing that unlike a sand filter, there is no advantage to a dirty cartridge filter. Water flow is still very strong at 15 psi. Aside from the time and hassle of cleaning it, is there a reason not to skip the manufacturer's recommended schedule of an 8 psi gain and clean earlier? I kinda want to just get this algae out of there...and with no ability to backwash, well, you get the picture.
 
Yep, I've been there. There is little to no benefit to having a dirty cartridge filter early on in the SLAM. There probably is some at the end as you are getting the last of it out and final clean up. But, there isn't nearly as much stuff to filter out at that point.

As long as the water flow from the returns is good and there is good circulation leave it alone. When you notice the flow rate slowing is the time to clean the cartridges.
 
Hi pooldv,
Well, color me confused... I clearly overshot my first attempt to SLAM... FC now reads 82, I did get PH back into the low-normal range at 7.4, CYA is still up there (too much dichlor a few days ago, and the most bizarre part is that my cc seems to be lower than the FC, at about 45.

My kid insisted on jumping in for a little while, and all of the turbulence in the water has turned it from a cloudy blue to a very light grey/green. I put several more inches of water in, to dilute both the chlorine and lower the CYA, but I am unsure as to what to do next, if anything. Last I checked, filter pressure was up just one more pound, to 16 -- a gain of only 3 pounds since installing a new cartridge.

Thoughts? Drink beer:)? Let it go overnight?
 
I think relax. :cheers: No worries, the FC will come down soon while fighting the algae and sun. Just keep an eye on it and don't let it fall below your SLAM FC level based on the Chlorine/CYA Chart. Keep rinsing the cartridge filter as needed and leave that pump on until SLAM is complete. Stay with it and don't give up. :)

- - - Updated - - -

Remember, testing PH is of no use during the SLAM. Don't waste your PH reagents until after the SLAM. :)
 
Hi Texas Splash,
Thanks. I am doing exactly that (nothing ;) right now. CYA is too high (80), so my shock levels are correspondingly up there. This is my first season with a cartridge filter (I had sand, and had used Zeolite), so I am looking forward to finding out what kind of polish (if any) this filtration system will put on the water.
More than that, I am glad that I came to TFP. You guys are extremely helpful in getting people like me out of completely guessing about chemistry and into a more logical, proven method for making the pool fun again. All our 8 year old knows is that it is hot outside and he and his buddies want to have fun in the pool.thanks to this site, I am able to help make his summer better.

Thanks,
David
 
Well, 82 oughta kill some algae! :shock: The light grey green is dead algae. Keep the pump running on low 24x7. Brush a couple of times a day to expose the algae to some of that 82ppm. :)

I think a lot like your 8 year old!
 

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Hi Pooldv,
It is going to be 90 or near it most days this week, so hopefully I have made enough of a start to allow some real swim time.
Sorry to ask such a new by question, but I am pretty sure our pump only has one speed. Is it a newer innovation...? I think our pool would greatly benefit, and the energy bill would be less of a concern.

Thanks,
David
 
Yes, older pool pumps are single speed. If yours is 2 speed there will be a toggle switch on the back to flip between low and high. If you are in the market to look for a new pump to save electricity and your rates are high then take a look at variable speed pumps. They are completely adjustable in 5rpm increments.

I have a 3hp VS pump that normally runs at 1100 rpm for skimming, filtering and making chlorine with the SWG. The pump only draws 150 watts at 1100 rpm. Solar pushes it up to 1950 rpm which draws 550 watts.

Pentair also makes a 1.5hp VS pump. Pentair SuperFlo VS Pump 342001 | Pentair 342001 And there are probably rebates from your electric company if you buy one.

ps, I mention Pentair only because that is the brand I have, am familiar with and it has worked well for me. If you prefer Hayward they also make good products and likely have similar products available.
 
Hi Pooldv,
Thanks! This sounds like a great way for me to better maintain this pool. As my signature shows, we have an in-ground, kidney bean gun ute pool that is about 32 feet long and (I estimate) holds right around 18,000 gallons. Our current single speed pump is (I believe) 1 1/2 hp. The filter is a Hayward C-1750 cartridge type. New filter cartridge went in two days ago, and the working psi at that time was 13, WITHOUT the 4 passive solar panels that are mounted on an adjacent flat roof in the loop.
The pump was installed before the solar panels, and I had no idea if the pump could push the water up to the roof-mounted panels or not. It does, and the psi goes up by about 5 to 6 pounds.
Any idea as to the size pump I would need that is variable or two speed? This sounds intriguing...

Thanks,
David
 
Blue and hazy is good.

My poolmath calculation says for 18k from 5 to 28 is 530oz of 10%. 45 CC is a lot!

I think the 1-1/2 hp VS pump I linked to will be good.
 
Hi Pooldv,
Does cc go away or get lower? I have been so focused on FC that I. Have never given CC much thought... plus, I am still learning how to do these tests correctly.
My filter cartridge was finally clogged enough to push psi to 23 --10 pounds over when installed as new. I hosed it off really well, and pressure was back to 13 upon re-insertion.
I only put. In two gallons of liquid chlorine. I guess I will find out in the morning how far off that was...

Thanks,
David
 
Hi Jbizzle,
Thanks! I will retest this morning. I am still getting used to how to do the various tests, so you are probably right about it being wrong because of my lack of testing experience. I am using the Taylor kit with the powder. Should that be a heaping tiny spoonful or level (not easy with how small it is) or...?

I still would like to know what function the CC score serves. If it is partly made up of waste (chloramines), how is that number changed? Through time? Cleaning the filter? Chemicals? And is there a target CC number?

Thanks,
David
 
Hi Jason,
I re-read the ABC's of pool chemistry, and I see what you mean. I will re-test. The water was super green and nasty when I started, so hopefully it is getting back in line.
I still don't understand what happens to the CC (in any amount). Does it dissapate? Does it have to be physically removed by cleaning the filter?
I will continue to SLAM the pool with liquid chlorine, and work on getting better at my test methods.


Thanks,
David
 

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