White mold on cartridge filter or not?

[2WeeksNotice]

Need some assistance: 2nd year with the pool and new to TFP in the past month and learning a lot. Rinsed filters today (~3 weeks since last cleaning) and found white slimy substance, per the pic. Some of the small white balls were floating in the filter housing. Want to know if it's white mold and if need to SLAM or not.

TF Pro Kit numbers from tonight: 7.2 pH; 6.5 FC; 0.5 CC; 575 CH; 100 TA; 70 CYA.

Added ~600 gal well water 2 days ago and used a Blue Water pre-filter (not sure if this is necessary or if it's causing issues?). The numbers from tonight are pretty reflective of where the pool's been...with FC maybe a bit higher in the 8-11 range.

Water was a slight bit green after adding the 600 gal, but figured this is normal. Cranked the Cl up a bit after that as well. Yesterday and now more today the water is cloudy and the filter stuff has me concerned. I have 2 sets of cartridges, so those in the pics are soaking in TSP. The other set is in the housing now and in operation.

Thanks for any help!
Allen

 

[YippeeSkippy]

Do you have metals in your fill water that caused you to try that BlueWater Pre-Filter device?
How hard is your water there? Your calcium is pretty high for a fiberglass pool. Do you ever see white flakes in the pool?

Make sure you're following the FC/CYA chart and add enough to cover the sun's daily "burn off tax" in addition to swimmers.


Maddie

 

[2WeeksNotice]

Thanks for your response Maddie. Just now took a CH test out of the hose/well water. It is 450. Before getting to TFP recently, I had used CalHypo a few times to shock, so that may be why the CH is so high? We have not seen white flakes, just the gunk on the filters today.

The pre-filter is what I've used on our hot tub per the place we bought the tub, as they say metals are high in this area/aquifer.

Keeping FC/CYA at appropriate levels has not been a problem at all. Just cloudiness (I think you replied to my first post a few weeks ago on that and water smell). The couldiness went away some since that post, but now has returned significantly after adding the well water.

What next?

Allen

 

[2WeeksNotice]

Ran OCLT and it was 1.5 so starting a SLAM. pH is 7.2.

General question: if SWCG CYA recommendation is 60-90, but SLAM becomes harder to do at 80-90 CYA, then why even mess with that high of CYA? Just keep it 50-70 to play it safe? But I guess the point is you shouldn't have to SLAM...
Thanks for any advice if I"m on the right/wrong track.
Allen

 

[Texas Splash]

then why even mess with that high of CYA? Just keep it 50-70 to play it safe?

We have found, and so are more cell manufactures, that the cell operates more effectively with a CYA around 70. That's because the smaller amounts of chlorine gas generated throughout the day are protected better with the additional CYA. There is some flexibility with the CYA though. For example, in my area, if my CYA falls below 70 my FC responds right away by falling due to the intense sun & heat. But in your area, or pools that receive some shade, they may do fine with a CYA of 50-60.

The whole point is to save on FC production (cell effort) which should help to extend cell's service life by less run time/output. It's something you'll have to experiment with on your end.

 

[2WeeksNotice]

Thanks for that. Any comments on the gunk in the pics and test numbers/SLAM starting?

 

[Newdude]

Just keep it 50-70 to play it safe?

For you in Illinois, that is a great plan. It simply isn't enough in the hot climates.

We recommend everyone start at the lowest range that thousands of members have reported works for their region, and increase by 10 if the FC isn't holding.

Any comments on the gunk in the pics

It could easily be environmental debris that fell/blew in. Sometimes you need a couple seasons under your belt to just instinctively know it's cottonwood (etc).

test numbers/SLAM starting?

You failed the OCLT. SLAM away. As someone new to the program, I really prefer the SLAM to wipe the slate clean going forward.

 

[2WeeksNotice]

Newdude --understood and agreed. thanks for the comments. SLAMing. Also some very recent posts (and local folks) are speculating on the heavy Canadian wildfire smoke/haze is increasing cloudyness. We had a bad week last week with that. Air quality index of 200+. Not good.

 

[Newdude]

Also some very recent posts (and local folks) are speculating on the heavy Canadian wildfire smoke/haze is increasing cloudyness.

The ash can do a number on clarity, PH and FC.

 

[Mdragger88]

If it is white water mold (which is actually a bacteria) the SLAM Process should take care of it. Usually that looks like tissue paper in the water but whatever is going on the slam is the answer.
If you drink that water it may be time to treat your well.

About the cya/swcg recommendation…

But I guess the point is you shouldn't have to SLAM...

Bingo you nailed it!
For the most part the use of an appropriately sized swcg makes maintaining adequate fc levels easy so most people never need to slam (barring an incident of some sort).
Before going to the higher cya levels (making big cya additions) it’s always a good idea to do an Overnight Chlorine Loss Test first.
Confirm you’re algae free & then stay that way.
Your swcg cell is undersized for your pool volume. If it is the t5 listed in your profile banner.
A 20k gal rated cell in a 20k gal pool.
The manufacturer ratings are such that they expect you to run them 24/7 @100% to maintain adequate fc levels.
We recommend that you have a cell rated for at least 2x’s your pool’s volume so you have plenty of wiggle room with fc production & the cell doesn’t deplete its 10k hour lifespan in such a short time.
The max fc the t5 cell can produce in a 24 hour period in your pool is around 4ppm.

This may not cut the mustard in the peak times & you may need to be vigilant & supplement with liquid chlorine. The average fc loss in an algae free pool is between 2-5 ppm/day depending upon conditions.
Maintaining a higher cya level (around 80) can help protect more of the fc the cell produces as mentioned above.
When it’s time to replace your cell you should opt for a t15 (40k gal rated) one.

 

[2WeeksNotice]

If it is white water mold (which is actually a bacteria) the SLAM Process should take care of it. Usually that looks like tissue paper in the water but whatever is going on the slam is the answer.
If you drink that water it may be time to treat your well.

About the cya/swcg recommendation…

Bingo you nailed it!
For the most part the use of an appropriately sized swcg makes maintaining adequate fc levels easy so most people never need to slam (barring an incident of some sort).
Before going to the higher cya levels (making big cya additions) it’s always a good idea to do an Overnight Chlorine Loss Test first.
Confirm you’re algae free & then stay that way.
Your swcg cell is undersized for your pool volume. If it is the t5 listed in your profile banner.
A 20k gal rated cell in a 20k gal pool.
The manufacturer ratings are such that they expect you to run them 24/7 @100% to maintain adequate fc levels.
We recommend that you have a cell rated for at least 2x’s your pool’s volume so you have plenty of wiggle room with fc production & the cell doesn’t deplete its 10k hour lifespan in such a short time.
The max fc the t5 cell can produce in a 24 hour period in your pool is around 4ppm.
View attachment 509638
This may not cut the mustard in the peak times & you may need to be vigilant & supplement with liquid chlorine. The average fc loss in an algae free pool is between 2-5 ppm/day depending upon conditions.
Maintaining a higher cya level (around 80) can help protect more of the fc the cell produces as mentioned above.
When it’s time to replace your cell you should opt for a t15 (40k gal rated) one.

I have a T940. Sticker on it says size for 40k gallons. I don’t think the profile banner default selections included my model (??).

SLAM in process. Clarity improving. Thanks again!

 

[proavia]

I have a T940. Sticker on it says size for 40k gallons. I don’t think the profile banner default selections included my model (??).

SLAM in process. Clarity improving. Thanks again!

Your profile usually won't show the exact cell you have. But I can see you have a 940 from your signature.
The 940 is basically a T-15 cell - and as you state, it rated for a 40k pool.
We recommemd a SWG rated for at least 2x your pool volume.

 

[Mdragger88]

I have a T940. Sticker on it says size for 40k gallons. I don’t think the profile banner default selections included my model (??).

SLAM in process. Clarity improving. Thanks again!

As proavia mentioned select t15 for your banner. Glad to hear it is adequately sized
You can use PoolMath effects of adding (in the hamburger menu) to help determine the optimal run time & percentage to ensure you’re covered with adequate fc going forward after slam is completed .

 

[2WeeksNotice]

Update: 4th day of SLAM complete. passed OCLT last night at 28FC with no drop at all; CYA holding steady at 70. 0.5 CC but water is a bit cloudy yet in the deep end. So continuing to SLAM.

I'd appreciate some experience/expert advice:

1. Clarity is improving slowly each day. Plastic screens on the walls at 2' deep appear to me to be in crystal clear water. But the 6' deep ones are not. Still just slightly milky. Am I getting too picky on the crystal clear? Seems like last year it was clear in the deep, but it was a new toy last summer and everything about it was sooooo nice.

2. Removed the plastic screens on the walls last night and there was 1/2" patches of dull brown gunk on the bulkhead underneath the screen. Also very light brownish witness mark/stian line on the wall outside the screen. The bulkhead gunk wiped off easily and turned to dust. The staining on the walls did not. Any comments there?

3. Today was 90F and humid, sunny day with cover open all day. FC dropped from 28 at 6:00 AM to 17 at 2:30 PM. CYA is 70. Would this much be normal sunlight loss, or is there still something the FC is working on?

4. The cloudiness before the SLAM started after adding 600 gal well water and using a pre-filter for metals (recommended by pool installer, I also use this on our 400 gal hot tub with no issues). If the water addition is the source of the issues, and I want to test my well water, what parameters would I test for? Or did I just not get enough CL added with the new water? What's a good plan for next time adding water: bump up with LC to 1/2 SLAM level before adding water?? Or advise other ideas.

Thanks for any help!

 

[Newdude]

You can have dead, or mostly dead algae that doesn't use much/any FC. But you keep the FC elevated just in case until the water is TFP clear. And I'm talking HOLY COW where did my water GO ????? Clear.

Also, brushing and vacuuming may expose new algae layers on the walls that you want promptly killed by the SLAM FC.

Stay the course. It's MUCH easier to fight when the FC is holding well. Gift horse and whatnot. Lol.

 

[2WeeksNotice]

And I'm talking HOLY COW where did my water GO ????? Clear

that's what I'm talking about!! Thanks for the encouragement. Any help with the other questions?

 

[Newdude]

The staining on the walls did not. Any comments there?

Possibly iron stains. Try rubbing Vitimin C on it.

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

Would this much be normal sunlight loss, or is there still something the FC is working on?

You'll probably lose 4ppm on the highest UV / hottest days in illinois. FC burns off as a %, so it does so faster at higher levels and becomes noticeable in the 20s. You lost normal UV, elevated FC loss and whatever the algae consumed.

It's par for the course.

If the water addition is the source of the issues, and I want to test my well water, what parameters would I test for?

Run the full suite because it's easy to do. Then take a sample to 3 pool stores specifically for metal testing. Make sure they can specify copper and iron and not just 'metals'. Take the 2 readings that are closest and use that as your best guess. There are no cost efficient tests for a one time metals check, so we rec the poolstore, but just because they test it, doesn't mean they're anymore better at it than their other tests.

Or did I just not get enough CL added with the new water?

This is my vote 99% of the time.

What's a good plan for next time adding water: bump up with LC to 1/2 SLAM level before adding water??

Just make sure you're free and clear above minimum when you start. Mix well and test 15 mins after to make sure you're still golden until the next test time.

600 gallons is 3% of 20k gallons. You can expect your #s to dip 3%, and that's .18 if your FC is a 6. You'd never even know. If 3% can throw you for a loop, you were way too close to minimum.

I can't be bothered keeping close tabs on it. I run hot and rarely have to step in. I'm also never caught by surprise that XYZ gave me a swamp.

 

[Mdragger88]

This will be you soon

How Clear is TFP Clear?
You can have your fill water tested for copper & iron at the pool store. Iron is often a concern in well water.
You can also test it yourself for fc, cc, ph, ta & ch - just record the results for future reference.
If cc’s are crazy high you may need to treat your well (especially if you drink that water/use it in your house) you can get usually your well water tested for coliforms & bacteria (along with other contaminants) at the health department Well Testing | Wells | Private Water Systems | Drinking Water | Healthy Water | CDC
If you have a
PoolMath subscription (highly recommend for $8/yr) you can have logs for multiple “pools”
I have one for my pool, one for my hot tub, & one that is fill water for easy reference.
About the filter for filling, that’s a good idea to do in your case- there’s a few ways to skin that cat

Iron Fill Water Filter - Further Reading

www.troublefreepool.com

 

[2WeeksNotice]

Thank you both for the prompt responses and help! Haven't had time to read all the link details on iron etc, but will get to it. Staining is not severe. My focus right now is on the clarity. This morning it was almost at crystal, the end is in sight! No FC drop overnight (again) and 0.5CC. One or two more days of SLAM, I'm hoping. The people and knowledge are what make this site/forum work so well. Can't not support that!

 

[2WeeksNotice]

Crystal. Clear. Today.

Thank you!!