Staining Due to Algae?

[teamhurtado]

Happy Memorial Day folks! I'd love to be swimming in my pool, but there are a few reasons we can't, even though it's just been a brutally hot spring here in Florida (there's that tropical storm too but we've seen worse.)

First, the setup for our family pool includes:

• Built in 1991
  I believe Gunite material
  11,000 gallons
  Hayward C1200 cartridge filter with 1-month old cartridge from Leslie's (the core has rectangular opening for water flow)
  3' In-line chlorination tabs from Pinch a Penny (the ones with the blue specks)
  MX8 Barracuda hooked into skimmer line as I couldn't find an adapter for the dedicated drain line that would keep the hose in place

About 2 months ago, we could not for the life of us get the pool in a crystal clear blue state. After shocking with Leslie's Power Powder Plus and replacing the filter cartridge, we finally were able to clear things up. Chemistry in the system came back perfect according to their in house guidelines including phos levels at 0 (as a side note, they wanted to know if I was using their Phos Free liquid to which I said no. They were shocked, hah!) However, I've attached photos of the staining left behind.

https://picasaweb.google.com/103596...&authkey=Gv1sRgCJjlrr6a5qyDDg&feat=directlink

I spoke with the folks at Leslies and performed the vitamin C tablet test. No reaction lead me to believe it was not metallic and therefore gunky stuff left over from the pre-clear state. We went back to Leslies this weekend and explained our situation. Ended up walking out with 2 5oz bags of their Yellow Stop powder plus 4 bags of Power Powder Plus. As of this writing, we're wrapping up the procedures that they provided for us in attempting to remove the stains.

Here's the problem. Even with a metal brush, those stains in the photos above are not going away. As I scrub, all I see is some white powder being lifted off the stairs, which quite frankly scares me a bit.

Question 1: If those photos are clear enough, are those stains organic materials that won't go away easily, ala black algae?

Question 2: I know the pool is 21 years old and, at least to my knowledge, has never been resurfaced, acid washed, etc. Given the answer to question 1, is it perhaps time to resurface the pool? I believe no work has ever been done on both the pool and the pool deck (which is now cracking.)

The only reason I believe those stains are organic is that my pool filter will clog up within 24 hours. As an example, this morning around 10 am, the cartridge filter was cleaned. Baseline PSI for the filter is about 12. By lunch time, the PSI was up close to 30 with a lovely green film coating it.

Help!

 

[JasonLion]

That isn't black algae, it is too green and not the right shape/pattern. Either live algae or organic stains are the most likely. There is a simple test for both of those. Place a trichlor tablet on a stain for a couple of minutes, if the stain lightens significantly then it is either live algae or an organic stain. If it is unaffected then it is something else.

I would stay away from Yellow Stop. It can occasionally work miracles, but it is more likely to create complications.

Can you post a complete set of water test results?

 

[teamhurtado]

That isn't black algae, it is too green and not the right shape/pattern. Either live algae or organic stains are the most likely. There is a simple test for both of those. Place a trichlor tablet on a stain for a couple of minutes, if the stain lightens significantly then it is either live algae or an organic stain. If it is unaffected then it is something else.

I would stay away from Yellow Stop. It can occasionally work miracles, but it is more likely to create complications.

Can you post a complete set of water test results?

I knew you would ask for water results!

TFT 100 kit is on the way. Leslies wants me to take in a water sample tomorrow once their Yellow Stop treatment is complete. Had I seen this site prior to initiation of their treatment, I would have stopped. D'oh! Once I get a water sample into them tomorrow I can post the results. I'm hoping the TFT kit will arrive by Thursday to get this squared away. I'll attempt the tricor tablet once the rains let up this afternoon as I have to go and clean the cartridge filter again. Thanks!

 

[duraleigh]

JasonLion's suggestion to stay away from Yellow Stop cannot be overemphasized.

Your kit will ship tomorrow and will be to you in Florida on Thursday.

The more you stay out of the pool store, the more you will learn about managing the water yourself and the more money you will save.

 

[teamhurtado]

JasonLion's suggestion to stay away from Yellow Stop cannot be overemphasized.

Your kit will ship tomorrow and will be to you in Florida on Thursday.

The more you stay out of the pool store, the more you will learn about managing the water yourself and the more money you will save.

You sir... are just awesome. I knew awesome people came out of NC (like my wife!)


Jason,

I placed a trichlor tablet on a really ugly spot. Sure enough, the area under the tablet lightened up significantly. Given what I've read so far in Pool School and from some other threads, I'm suspecting that my FC is probably negative at this point (yes, negative) and my CYA is probably fairly high. I'll have some solid numbers Thursday though.

Also, my pregnant wife and I are having a small "debate" on whether or not to use Clorox in our pool. Any way I can make her see the light or is it just best not to argue with a pregnant person?

 

[JasonLion]

Standard household bleach is the exact same chemical used by many public pools to disinfect the water, just at a slightly lower concentration than commercial users purchase. Clorox even mentions it on their web site is a couple of places, for example here though I can't find their more complete instructions just at the moment.

 

[Richard320]

Also, my pregnant wife and I are having a small "debate" on whether or not to use Clorox in our pool. Any way I can make her see the light or is it just best not to argue with a pregnant person?

Hormone monsters are hard to reason with....

Best bet is to buy "liquid shock" or "liquid chlorine" from a pool store or Lowes or Home Depot. Some pool stores sell the 12.5% stuff in returnable jugs. Otherwise, you'll find 10 or 12.5% stuff usually 2 gallons to a case. Same stuff, slightly stronger, might be slightly more expensive, but it's not bleach! Hopefully, it will have some sort of perky graphics depicting a swimming pool on the box.

 

[teamhurtado]

Evening folks. The TFT-100 has arrived. I believe today is the last day I ever have any pool supply perform my testing. Here are my results:

• FC: 1
  CC: 0.5
  TA: 70
  CH: 520
  CYA: 30
  pH: 7.2

Here's my plan of attack:

• Clean cartridge filter
  Add ~2 gallons of 10% bleach to system which should bring FC to ~20 (Yellow/Mustard level)
  While bleach is working it's magic, brush/clean system
  Verify FC level holds at ~20 until OCLT can be performed successfully

First, at this point I'm assuming I should shut down my in line chlorination, perhaps for good?

I'm a little hesitant to trust the CH test but I followed the TFT kit as instructed. I believe the high CH results may be a result of the 4 bags of Power Powder Plus dumped in the pool on Sunday. Since we're about to enter the rainy season here in Florida, I'm also a little hesitant to partially drain and refill to bring CH down to a reasonable level. I'll retest CH after I pass OCLT in the hopes that levels will have dropped somewhat during the shocking process.

Is it possible for high CH levels to clog a cartridge filter almost instantaneously? Since the yellow shock over the weekend, the filter jumps in pressure within the hour. Any time the filter's cleaned, there's always white powder and foam pouring out of it.

All other chemical levels look on point to start the shocking process. I'm hoping this will help get rid of those organics that have made their home on our pool surface. Anything else I missed?

Before and after pictures will be taken to show how easy this really can be. Thanks!

 

[Richard320]

Calcium won't clog your filter, unless you dumped a bag of quicklime or concrete or mortar mix in there.

Your CH may be that high, it sorta depends on the tester. If you're using a speedstir, it's probably pretty close. If you're swirling by hand, it's probably not really that high. With a speedstir, sometimes if I just run it another cycle - a minute, I think - it will change from purple to blue with no extra reagent. By hand, that's about 3 minutes of mixing! My CH went down miraculously about 200 ppm when I got a speedstir.

 

[teamhurtado]

Richard,

I'll recheck CH again once this is all over. Thanks for the heads up!

I'm not sure if I'm having issues with my cartridge filter or if there's so much crud in the system that it can't keep up. I started the shocking process about an hour ago and will be checking FC levels every hour. On the first check, the system PSI jumped 200% from 10 to 30 PSI. Is it typical during the shocking process to clean a cartridge filter nearly every hour? The cartridge is only about a month old so I don't think it would have failed yet but I'm not entirely sure. At $90 a pop, I would prefer not to replace it, again. Thanks!

 

[teamhurtado]

Shock treatment started at 3:00 today with 2 gal of 10.4% bleach. Filter has been cleaned and pool swept. At 4:20, FC came back at 3.5 with CC at 2.0. Filter was clogged so I'm wondering if I had any circulation through the system at that point. At 6:00, FC was 2.0 with CC at 1.5. Filter was again clogged so we went ahead and cleaned it. There was a fair amount of green goop in the filter so I know the process is working. Since FC appeared to decrease, I went ahead and added another 2 gal of bleach to the system. Is it possible to have FC consumed so quickly by organics after such an initial shock?

 

[jblizzle]

This does not sound like the Shocking Your Pool process. You have to keep the FC above 12ppm (for CYA of 30ppm) at ALL times ... NEVER let it drop. And use the poolcalculator to know how much bleach to add ... don't just keep randomly putting in 2 gallons (pardon me if you actually did this, as 2 gallons of 6% bleach happens to be about correct ... although you said you used 10% so you still may be overshooting)

You should be testing and adding bleach every hour or so to start.

And yes the FC will be consumed quickly. And yes it will clog your filter quickly.

EDIT: I now realize you are shooting for the Mustard Level, so 2 gallons of 10% was probably correct; however, why did you not add more bleach at 4:20 when it was first discovered to be low? Or did you and it dropped again by the next test?

 

[teamhurtado]

This does not sound like the Shocking Your Pool process. You have to keep the FC above 12ppm (for CYA of 30ppm) at ALL times ... NEVER let it drop. And use the poolcalculator to know how much bleach to add ... don't just keep randomly putting in 2 gallons (pardon me if you actually did this, as 2 gallons of 6% bleach happens to be about correct ... although you said you used 10% so you still may be overshooting)

You should be testing and adding bleach every hour or so to start.

And yes the FC will be consumed quickly. And yes it will clog your filter quickly.

I was curious how quickly FC would be eaten up. If it's that quick, then it makes sense. My spreadsheet and timer are set to grab data approximately an hour apart (depending on when the 2 year old allows me to test!)

Off the shock table, I'm using the mustard algae shock levels which may be why it appears that I'm overshooting a bit. 20 ppm should translate to approximately 2 gallons of 10% bleach. I believe the calculator specified 1 gallon, 3 quarts, yadda yadda, hah! Thanks for the help!

 

[jblizzle]

Sorry, I was a little mixed up.

My point is though, you should not be waiting for it to drop and then add 2 gallons. In fact, you should not be letting it drop below 20ppm if that is your goal (although down to 12ppm would still work). If you are testing hourly and adding the amount of bleach you need to stay above your target, then you are on the correct process.

 

[teamhurtado]

Sorry, I was a little mixed up.

My point is though, you should not be waiting for it to drop and then add 2 gallons. In fact, you should not be letting it drop below 20ppm if that is your goal (although down to 12ppm would still work). If you are testing hourly and adding the amount of bleach you need to stay above your target, then you are on the correct process.

What threw me off was that at the start of the shocking process, after 2 FC tests in 2 hours, I wasn't seeing the increase in FC predicted. It makes sense though if FC was being eaten so quickly due to the organics in the water. Ever since that initial 2 hour period, FC's holding between 18-20 with an accidental (my bad) spike up to 33. At this point, we're cleaning the filter about every 2 hours with milky white material being rinsed away. I know we're on the right path at this point as we've hit that bluish cloudy phase. What's even nicer though is that those stains on the stairs and wall linked to in the opening post are starting to fade with some good scrubbing.

Speaking of scrubbing, the folks at Leslies are discouraging me from using a metal brush. Is there any consensus within the forum on metal brushing with gunite pool surfaces?

 

[Butterfly]

Brush recommendations:

Nylon is for vinyl, fiberglass, tile, and plaster that is less than one year. (Plaster includes any exposed aggregate and marcite finish, btw!) Combo brushes are for older plaster. All stainless are for algae (very stubborn green algae and also the ONLY brush for black algae.)

You CAN unscrew the Wall Whale from the nylon brush it comes with and screw it on a combo brush if your plaster is over a year old. Newer plaster is really too soft for anyting other than a nylon brush.

 

[teamhurtado]

Brush recommendations:

Nylon is for vinyl, fiberglass, tile, and plaster that is less than one year. (Plaster includes any exposed aggregate and marcite finish, btw!) Combo brushes are for older plaster. All stainless are for algae (very stubborn green algae and also the ONLY brush for black algae.)

You CAN unscrew the Wall Whale from the nylon brush it comes with and screw it on a combo brush if your plaster is over a year old. Newer plaster is really too soft for anyting other than a nylon brush.

You know what the neatest thing about TFP is? I've never heard of half these products you all talk about but they're so freaking neat. Thanks!

 

[jblizzle]

The wall whale is AWESOME ... so much easier to brush the walls without having to try to put torque on the brush to get a good scrub.

 

[teamhurtado]

The wall whale is AWESOME ... so much easier to brush the walls without having to try to put torque on the brush to get a good scrub.

I think once this is all over I'll pick one up. How well does it work with corners/sides of stairs and walls? Right now, my biggest issue is getting these nooks and crannies on the stairs to push out whatever organics are left.

As of 9:00 this morning, FC is holding around 26.5 (from 33 the night before) with CC at 0.5. FC is high because I overshot when I first started the process. I would say my lesson's been learned, but I'll make sure we never go through this again.

My daughter's forcing me to put some smileys on. Sorry!

 

[ouachita]

I'm no expert but I thought for mustard algae you shocked at normal levels until you passed the tests and then ran mustard levels for 24 hours.

Anyone care to clarify this?