Tiny white flakes in Pool

[gingrbredman]

7.4 is just fine PH. There is nothing you would do to move the PH away from 7.4, or if it was 7.6, all fine and really close to the suggested range. If PH is slightly lower, say 7.4 and you want to get to 7.6, normal pool use and aeration will move that needle in a day.

I was only saying earlier, if you wanted to try and lower your TA, you could try the steps listed in pool math to get you there. You really do not have to attack the TA if it remains stable and the PH is stable in the 7s. The way to do that is lower your PH to around 7.2, then aerate the pool to raise the PH back up to say 7.8, then muriatic acid again to lower the PH back down. You would repeat the process until your TA creeped down to the level you were shooting for.

The only issue with that process for me, and those with high TA fill water, is during the summer, when water is added because of evaporation, I raise my TA back up again and have to do that all again. I find the right level of TA for my pool is about 100. That is maybe higher that the TFP guidelines, but it stays there about all summer long, and my PH remains stable at about 7.4 all summer.

Let us know when you have everything all cleaned up and when you get all those flakes out!

 

[TexEdmond]

Welcome and congratulations! You're a legit pool owner!

Do you know the amount of pump runtime and percentage you're using your SWG for? I'm concerned about your CYA and FC level. With FC 3ppm, you are running on the razor's edge of the low end on recommended levels, so make sure you're practicing the CYA test. It's okay to round up to the nearest 10 to calculate FC need, that'll just mean you'll be slightly over chlorinating which is still completely safe. It's also good to reuse the CYA test water for multiple measurements on a single sample, just pour it back into the squirt bottle. You might also be seeing a slight reduction in SWG efficiency with the scaling on the cell. If you find the CYA is actually lower than 70 after a few more tests and you're still swimming in the pool for a few more weeks / months you might want to slowly raise your CYA levels so the SWG has a better chance against sunlight. Use PoolMath app to calculate amount of dry stabilizer to add, then add half that amount in a sock in front of returns or in a skimmer, then give it a day to circulate and dissolve before testing. Then add the other half. Stabilizer is one of those chems that too much can really hurt and it's very difficult to reduce quickly.

It's a good idea to adjust your SWG to produce a little more FC. Some of us run our pools even higher than the recommended FC/CYA Levels zone. I'm a new SWG owner and try to keep my pool between 7-9 FC with 70 CYA just for the extra buffer. The sun is dipping farther behind the trees in my yard so I'm slowly reducing this as I notice FC creeping up towards 10.

Other reasons you might see scaling: if the cell is already running at a high percentage throughout the day it might be improperly sized to the pool. We recommend a 2:1 ratio for salt cell capacity to pool volume.

And lastly once you've got a good idea for how your fill water chemistry is, and when you've gotten a good handle on alkalinity and pH rising, after your plaster is good and cured, you might consider adding borates to your pool for added silky water feel and it also helps protect the salt cell from making more scale.

 

[Paulo88]

Let us know when you have everything all cleaned up and when you get all those flakes out!

Going to take them apart today to give them a good clean

Do you know the amount of pump runtime and percentage you're using your SWG for?

The pump runs from 10am until 6pm, and the SWG is set to 70%. Should I try pushing this to 80, 90% for a couple of days ? I also have it set to switch polarity every 3 hours to try to help prevent build up on the cell.

so make sure you're practicing the CYA test

I will run some more test today after I've cleaned out the pool and filters etc.

 

[TexEdmond]

Should I try pushing this to 80, 90% for a couple of days ? I also have it set to switch polarity every 3 hours to try to help prevent build up on the cell.

There's two basic fixes. Either increase your pool pump runtime or the cell run percentage. You have a variable speed pump, you might want to run it at a low speed for much longer. I run my pool pump 24/7 because at very low RPMs it draws around 150w of power, very economical and completely silent. The SWG percentage is just a straight multiplier. 50% runtime means that for every hour the pump runs, the cell is generating chlorine for 30 minutes. The cell itself either on or off. I have zero evidence to back this up, but I feel like my cell will live a long, happy life running it at 20% for 24 hours instead of 100% for just long enough to get my pool chlorinated then shutting everything off. There is some complicated water chemistry that happens inside the actual cell between the plates, and giving it time to rinse itself out and recover instead of continually building scale seems wise. EDIT: Now that I think more about this, running your pump / SWG for 8 hours & 70% is probably what the PB initially programmed, and I can totally see how this would lead to less than ideal conditions. Running 70% of the time then leaving stagnant water in the cell for the other 16 hours... I wouldn't do that to my pool if it had a VS pump. You don't have to do 24/7, but you could figure out a low RPM setting that you could run for 12 or more hours. It's also important to remember that running the SWG at night when there's no sunlight on the pool is a great way for the levels to catch up, because there's no FC loss.

Take a look at this spreadsheet one of our members built. It helped me to understand runtimes and percentages better instead of just using the PoolMath app which does all the work in the background.
SWG Run Time Calculator

I may have misread your FC test results. I see a 3 and a 6 on the same line. Tell us more about your test method. Did you do a 10mL DPD test and drop 6 drops?

Basically, my question revolves around figuring out whether you've got a correct amount of CYA in your pool. For SWG pools, we recommend a higher CYA level because since the cell creates a small amount of FC over a long time, and the pool needs extra protection from sunlight loss. If your pool doesn't have enough CYA, you will have to run the SWG at unnecessarily high levels just to keep up, which will cause to premature cell failure. If you're at 3ppm FC pretty consistently, you're going to want to make a change so your water stays safe to swim. It looks like your system is rated to up to 35k pool size, which should be plenty. Don't take this as gospel, but I put the best guess numbers I could find into the calculator. You might want to ask your PB to come give you a once-through on programming your pool equipment, or you could just figure it out yourself.

 

[Paulo88]

I may have misread your FC test results. I see a 3 and a 6 on the same line. Tell us more about your test method. Did you do a 10mL DPD test and drop 6 drops?

Yeah was confused by this test result too as I did the Chlorine Test using the K-2005 kit as described in this video https://youtu.be/OPAAlGxlBYM?t=55 and was reading this as 3 6 on the block.

However looking at the block just now I realize that the 6 was for the Br test.. Rookie mistake DOH !

When I did the FAS/DPD Chlorine Test it took 6 drops (6 x 0.5 = 3) to turn it back to clear. Which confirms the first test of a reading of 3

I've gone back and edited my result.

running your pump / SWG for 8 hours & 70% is probably what the PB initially programmed

This is correct.
I can easily alter the run time of the pump and I think this is certainly something that is worth a try. If I'm reading the Calculator sheet above correctly, if I increase my run time to 12 hours a day I can reduce my SWG output % to 50.



My RPM's are also legacy from the PB set up and are currently set to 2750. I can try reducing this to 2000 if Im running for 12 hours.

 

[TexEdmond]

It might be a good idea to plan for a net increase of a few PPM just to get out of the danger zone. Don't just plan on replacing 2ppm per day if your loss is more than that, I just put that in there for round numbers. What a lot of folks here do is turn their pump down 100rpm at a time til the flow sensor turns the SWG cell off, then push it back up 200rpm or so. Then they run a separate timed circuit that kicks the RPM up for as long as it needs to keep the surface skimmed.

You might consider calculating runtime and percentage for 4ppm and checking your levels after a day. Or you could instantly raise FC by manually adding chlorine. Biggest issue right now is raising your FC a few PPM as soon as possible, you're right at a level that will leave you susceptible to algae.

 

[Paulo88]

You might consider calculating runtime and percentage for 4ppm and checking your levels after a day.

I will do this and repot back.

 

[Paulo88]

So I've managed to raise my Chlorine from 3 to 5. I did this by leaving the SWG set to 70% but increased the length of time I ran the filter (nearly doubled).

I do now have a few question on what I should do next. to keep it at 5 ? I obviously don't want it to stay with these settings as I've raised it 2 points in just over 48 hours.
I think running the filter for longer and reducing the SWG % may help with the build up too.

So,
* What PPM should I calculate to lose per day.
* Is there anything I else I should be tracking now that the FC has increased.

What would you recommend I do now moving forward.

I will also mention that I think I'm seeing less flakes, but not completely gone. Or this could just be wish full thinking lol.

 

[TexEdmond]

Great job! Congratulations on taking full ownership of your pool. "Now let's see how far the rabbit hole goes..."

Now that you've got your FC levels up, what I personally shoot for on my SWG pool is 70 CYA and anything less than FC 10ppm is just fine. There's no downside to having a few extra PPM of FC in a SWG pool with 70 CYA as long as you stay below 10ppm Since the chlorine is effectively free (or very, VERY cheap), it makes sense to give myself several days of margin and I can get really lazy with no worries of algae. Above 10 the pH test becomes unreliable, and for me that's the only test that I focus on day-to-day anymore. Why? Because now that my other numbers have all settled down, first and foremost, the thing that will help keep scale from forming on my SWG is maintaining a slightly negative CSI. I believe I've seen the really knowledgeable folks here say below +0.1, but the general concensus is no higher than +0.0 and no lower than -0.3. Do you have the PoolMath app yet? CSI isn't a direct measurement, but is based on a number of the other tests you should be regularly testing. pH is a large factor, but you'll quickly see how TA and CH, even water temperature play important roles. As you start working on these numbers you will likely find your pool maintenance is running like clockwork and is very easy.

To your question about FC: Running the pump longer at a lower SWG percentage is still totally an option, and it's all up to your personal preference. As long as the salt cell has enough water flow, it will create FC. I don't have an awake enough brain to do the math right now, but with the increased runtime I'm hearing you say that at your current production minus bather load and UV loss, you're making 1ppmFC more than you lose per day, for two days. Looking at the spreadsheet you copied I'm seeing your SWG will produce 0.9 pounds (or 8PPM at your pool's volume) of FC in your pool. That's if you ran the pump 24/7 with SWG set at 100%, you'll make 8PPM / day. You're not running the pump or cell full-out, so you can take: (8ppm / day) * (0.7 Cell percentage) * (Hours of pump runtime) / 24. This gives you your daily chlorine PPM generated.

Now, I see this more-or-less as a conservation of mass problem: (FC end) = (FC start) + (FC generated) - (FC loss to bathers and organics) - (FC loss to environment). I actually modified my version of the pool care spreadsheet to do the math for me, because I'm lazy and this is how it fits into my weird head. I made the formulas automatic so all I need to do is put in the date/time and FC numbers from any two tests, and the calc spits out the correct SWG percentage. (note, I assume my pump will run 24/7, and I even gave it an adjustment for spa runtime, as that's a different SWG percentage level in my pool controls.) With no swimmers and keeping leaves out of the pool this equation becomes very simple indeed, and that's how I personally calculate my daily FC demand.

Questions you might want to explore

• Does your pool pump or automation panel tell you how many watts it is drawing at whatever RPM & CFM? You might find it's actually cheaper to run the pump at just a few hundred RPM over the minimum flow for your SWG to stay on. I've also read it's actually easier for VS pumps and their bearings / seals the lower you run them. I just make sure at least once a day to kick the RPM up to 3000 or so because my system tends to get some air bubbles in the baskets at very low RPMs.
• If it's quiet enough and you don't want to increase your pump hours, you might consider running the pump at night so your pool has higher FC in the morning rather than struggling to keep up during the day. For me I think I'd personally prefer a pool that started the day at 8ppm and slowly fell to 6 over the day, rather than one that struggled to stay at 6 all day and then sat there not catching up at night, only to barely keep up the next day. The total amount of FC created wouldn't change. This is all very strange for me to consider, because I just run my pump all day and don't even think about it because it's silent until the skimmer / floor cleaner setting kicks on.
• As you're continuing your full test panels, start paying attention to the other numbers in the Recommended Levels chart. TA and pH are changed with muriatic acid. CYA and CH levels really don't ever go down quickly in a pool unless you're draining / refilling, or there's heavy rain you're compensating for.
• If your fill water is low enough alkalinity, you might consider adding borates to your pool for added silky feel to the water, it makes algae even harder to grow, and can work wonders with keeping scale from building up on SWG plates. It also does a good job of stabilizing pH from climbing too rapidly with the tradeoff being it takes roughly twice the amount of acid to drop the pH in the pool.

Here's that extra math I added to the spreadsheet.

 

[Paulo88]

Thankyou this is all a great help!
It does feel great finally get ahold of the Chemistry of the pool. Its like being back at school lol.

Do you have the PoolMath app yet?

I do yes, I will enter my results and see what CSI I get.

Does your pool pump or automation panel tell you how many watts it is drawing at whatever RPM & CFM?

Yes, as seen below. (if this is correct) This is also legacy from the initial PB setup. I'm thinking of reducing the RPM to 2000 now that I'm extending the run time.

If it's quiet enough and you don't want to increase your pump hours, you might consider running the pump at night

This is an option but the pool is covered through out the day too which I'm presuming how I managed to increase my FC.

For me I think I'd personally prefer a pool that started the day at 8ppm and slowly fell to 6 over the day

Wow, I didn't realize you could lose as many as 2 points per day ! But I agree I would rather have this too.

I will admit I'm a little confused with the spreadsheet :/

 

[TexEdmond]

I'm thinking of reducing the RPM to 2000 now that I'm extending the run time.

This is a fantastic opportunity to experiment. My pool equipment, plumbing, and power cost is different so it's not a totally fair comparison, but I run mine 24/7 at RPM 1300 and it draws 150 watts, then it kicks the RPM up higher to do skim / floor cleaner / prime the pump. If you got similar efficiency you could run the pump for 24 hours at 1300rpm for the same cost as running it at the current speed for only 3 hours and 45 minutes. That's a HUGE energy savings!!!! It takes a fantastic amount of energy to pump water through pipes at very fast rates, and it creates a lot of noise. It won't hurt anything if you turn it down too low, your SWG will just turn itself off as a safety precaution. Turn the RPMs up 100 at a time until the SWG turns back on, then turn it up another 200 rpm or so to compensate for your filter slowly building pressure over the next few months. Other users only run their pump long enough to generate the FC they need and keep the surface skimmed then turn their equipment off. For this, try slowly reducing the RPMs from 2000 until you find a speed that you're not keeping the water totally clear of leaves and floaters. The first few weeks I did this at the slower speed I panicked every time I walked out back because I thought the pump had turned off. It is almost completely silent from 10 feet away.

Wow, I didn't realize you could lose as many as 2 points per day ! But I agree I would rather have this too.

The pool cover will definitely help keep FC levels up in the pool. There's no reason I'm aware of to have your pool pump running at high RPM with a cover over it, but hopefully someone else can chime in and help double check me. Yes, many pools depending on how far South you live, what season, water temp, and how much sunlight the pool gets can see 2-3ppm of FC lost to sunlight every day.

If you decreased your pump RPM to 1300 so and the system still functioned normally, with the pool cover on most of the time you might be able to run your SWG at very low levels. I'm noticing on my pool now that the water has dropped below 75 degrees and the sun is lower in the sky during the day my SWG went from 25% to 15% and I'm still keeping 9ppm in the pool, so I reduced it to 10% because I want to lower my FC to around 7.5.

What PPM should I calculate to lose per day.

I don't think I actually answered this, sorry. The pool determines this. Check your FC every day or every other day while you're getting these settings dialed in. Never let the FC level fall to the minimum for your current CYA, and it's a good idea to let it be even just slightly higher than the "recommended range". If today's FC test is the same as the last level you checked, congratulations. Your FC is in balance: the cell creates as much chlorine as the pool loses over time. If today's test is higher, use the calculator in the PoolMath app or the SWG spreadsheet to calculate how much to lower your SWG or runtime. If today's test shows a drop in FC from last time, you'll need to increase SWG / runtime.

Keep checking your FC levels every 1-2 days to make sure you aren't headed for disaster either too high or too low.

I will admit I'm a little confused with the spreadsheet :/

I'm sorry for confusing you. I'm inconsistent about checking FC at the same time every day, so that's why I built the calculator. Please forgive me. This is how I feel trying to explain my crazy spreadsheet math:

 

[TexEdmond]

This is what my pool pump sounds like at 1300rpm. SWG works just fine. That is our bedroom window, and it doesn't bother us a bit while we sleep.

New video by emcee gee

photos.app.goo.gl

 

[Paulo88]

This is what my pool pump sounds like at 1300rpm. SWG works just fine. That is our bedroom window, and it doesn't bother us a bit while we sleep.

New video by emcee gee

photos.app.goo.gl

Nice.. all I hear is insects

 

[Paulo88]

So I'm still playing with filter times and SWG% but I believe I have a handle on it and I'm slowly homing in on the right combination

Part of this process was to also reduce the pump RPM's, however I've noticed that when I get to around 2000 I get a small air bubble in the basket area. Which slowly grows over the day.

Is this something to be concerned about ? Should I run the pump at 2750 for a few hours to try to get rid of it or should I just leave it as it is ?

 

[TexEdmond]

I noticed the same in mine and thought I had an air leak. That's apparently totally normal. I've found I can just even run a few minutes at higher RPM and it clears itself out.

 

[Paulo88]

I've just done another full weekly test and I got a CYA of less then 30. In fact I filled the tube all the way and I could still see the black dot.
I'm guessing this is not good.

FC = 4
PH = 7.2
TA = 70
CH = 470
CYA = <30

Does CYA usually vary like this, we've not had any rain and no large spill outs or is it part of the chemical process of balancing a pool ?
There seem to be multiple ways to raise the CYA is there one you would recommend ?

 

[TexEdmond]

CYA does fall slowly over time, but not 20ppm. Granulated (dry) stuff is what I've used, but make sure to go slowly and not go past the final number. Allow 24 hours after adding for the chemical to fully mix, then test again. Use the PoolMath calculator to determine the amount you need to raise to the desired level, add the chemical to an old sock, and suspend it in front of a pool return. Some people put it in their skimmer basket. You can do this but I think it takes a bit longer for things to level out because it has to dissolve thru the filter and takes longer.

Don't despair! Run your pump and percentages a little bit longer, keep that FC PPM a little higher, and you'll be on autopilot before you know it and can start running the equipment a little less.

Great job!

 

[Paulo88]

Yeah that's what I thought. I've retested again today.

FC = 4
Ph = 7.4
TA = 80
CH = 480
CYA = 30

Again when doing the CYA test I could still see the black dot slightly. Looking at the ideal settings I should be between 60/90. Is this something I need to try to resolve as I'm still seeing small white flakes ?

 

[Paulo88]

Have you ever used SCALEFree ?

Do you think its worth adding to the pool to help remove the flake build up ?

 

[TexEdmond]

I don't even need to read the label to know that ScaleFree isn't going to help your situation. Your test results are all we need! Also, it's not uncommon that the "miracle fix" stuff from the pool store either has some unintended benefit that will cause further issues that you'll have to buy more crazy potions and elixirs to fix... Or it just simply doesn't work at all. If you've got a lot of scaling in your salt cell, it's a better idea to fix that at the source by removing the cell and cleaning it per the manufacturer's recommendations. Keeping your CSI slightly negative will help prevent further buildup when you get things back in shape, but with it sitting at +0.6 right now, you're likely going to see scale forming on all surfaces including your SWG.

I'm stumped. I just put the same numbers from your app into my CSI calculator and got -0.14.