Could this be algae or dirt/pollen?

I'm getting mixed feelings about this. We have had this show up in the pool. I shocked (with granular chlorine) and the chlorine level maintained somewhere between 5-10 the following day (using test strip). The pool company said I needed to brush the stuff off the floor to "meet" the chlorine, which I did. Still got the same chlorine reading the following morning.

The pictures posted are after we returned from a short vacation. The entire pool floor was covered. Assuming it was algae, I turned off the filter and triple shocked and brushed the entire pool floor. The following morning, I tested the chlorine and it was at least 10ppm (test strip doesn't go any higher). Now I'm back to thinking it's only dirt/pollen, so I started the filter and poured in clarifier. That was 2 days ago. The water is now dirty and cloudy and I can't see the deep end drain.

Specifics, if you need them (chemicals based on closest color test strip):
30,000 gal in ground vinyl liner
PH - 7.8
Alkalinity - 120
Total & Free Chlorine - 10 or above
Cyanuric Acid/Conditioner - between 50 and 100

Thanks so much for your help,
David

There are other folks here with lots more experience than I, who can be of better help but one thing you really need to do is get more accurate test result numbers. CYA from 50-100 is too wide a range to know what your proper Chlorine level should be. Also, you need to know your CL level ~ how much above 10ppm? Everyone here recommends using a better testing method than test strips. If you don't have a good kit, you can take a water sample to a reliable pool supply store and have the water tested for you.

One thing you can do is feel the stuff settling in your pool and see if it's gritty or slimy. That will help you to determine if it's dirt or algae. I'm sure someone else will chime in with some good advice for you.

I'm working on getting to the pool store today for a current reading (and will purchase a test kit). As for the feel - it's not gritty.

It is hard to tell from the picture but it looks like it could be mustard algae. You need an accurate set of test results so we can help you with it if it is mustard algae. Especially an accurate CYA reading since that will determine just how high you need to go with your shock levels to kill it.

DO NOT trust the pool store to give you accurate readings ESPECIALLY CYA

Also, keep your filter running; you mentioned you turned it off.

C.

Quote:

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Originally Posted by ShelleyAnn

DO NOT trust the pool store to give you accurate readings ESPECIALLY CYA

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This really depends on the store and who is doing the testing. Let's be fair now. I am the first one to say that many pool store employees who test water are clueless but there ARE a few of us good ones out there!;)

OK, back from the pool store. Here we go:

PH - 7.8
FC - 6+
TC - 6+
TA - 140
CYA - 80
Copper - .06

Pool temp is about 78F

I sampled the stuff and pool store says its algae. They are also a little confused that I still get chlorine readings with this stuff in the pool. They had me purchase Green Treat by United Chemical. I haven't put it in yet. It is sodium bromide based (48.5%).

Thanks for all your help!

DON'T USE THAT STUFF!!!!! YOU'll SPEND WEEKS ADDING TONS OF CHLORINE TO GET IT OUT!!!!!!! THE CURE IS WORSE BY FAR THAN THE DISEASE!!!!

It's only for desperation situations--which you do NOT have!

Nowhere have I seen that you VACUUMED your pool. Do so and see if it goes away and returns. I get all kinds of similar looking stuff on the bottom of my pool from pollen and dust and it just vacuums up and the pool chemistry is FINE. It looks a lot like that but it's definitely NOT algae--it is brown but not a problem.

I have tried to vaccuum and found it returning through the jets. I pulled the filters out to clean them, assuming they were at capacity, and found them to be rather clean except for a yellowish-greenish hue to the water running out of the cartridges. I have not tried vaccuuming since I put in the clean cartridges.

Vacuum to waste.

I have a cartridge filter (Hayward SwimClear). How do I vacuum to waste?

I don't know anything about a cartridge filter but with my sand filter I have a multi-port valve that can divert the water from the pump to several different locations (filter, waste, backwash, rinse). When I get something in my pool that the filter won't "catch" I'll vacuum to waste and this gets rid of it.

Apparently you don't have this option available. I'm not sure what to tell you, maybe someone else will chime in and help out.

Quote:

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Originally Posted by itstoohot

I have a cartridge filter (Hayward SwimClear). How do I vacuum to waste?

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With a cartridge filter you can't. Carts can filter down to 20 microns which is pretty small. you can't filter out live algae....you need to kill it.

Quick update -

I vacuumed this evening (all the big stuff lying on the floor) using a skimmer sock, then removed the cartridges and replaced with clean ones. Afterwards, the water was tested and I got:

TC - 3
Ph - 7.6/7.7
TA - 110
CYA - assumed to still be at 90 (tested yesterday)

Using a test strip for free chlorine, I got 3.

After a little hesitation (since we are using a Nature2 cartridge), I put in 10.5 gallons of bleach (6%) to get to 23ppm, which is the approx. shock level for CYA at 90 according to table posted in this forum.

Am now running the filter 24/7.

Hope to have more news (good or bad) in the morning. (I think I'm using parentheses too much?)

Sounds good! When things go bad, forget the N2. Then when things go good, you'll realize it costs you more in annual cartridges alone than you save...$105 buys a LOT of chlorine...

The N2 claims to cut your chlorine usage in HALF...that means you have to spending $210/year on chlorine wihout the N2 to break even...that's a heckuvalot of bleach...

Well, some of the stuff may have returned through the return jets as I have some laying on the pool floor this morning. It doesn't seem to be as much as it was last night, so that's good news :D . I will vacuum again this evening and change out the filters again.

The CL tested this morning at 20-25 (had to dilute the HTH drop test kit), which means that it held the CL I put in last night. Right now I can only test free chlorine with a test strip unless I take water to the pool store. It came out much darker than 10. I did order Ben's kit over the weekend, but it'll be a little while until that arrives.

Another update coming this evening.

Just heard from the wife who tested the water again. Apparently there is no change in the CL level. Have we not gone high enough (20-25ppm with CYA at around 90), or could all this stuff actually be something other than algae?

Well, each day seems to better than the last. At least the monsoon seems to have ended :D . Today, the water is clearer (I can see the deep end with a slight haze). Looks like the persistent vacuuming and changing out the filters is working. There is very, very little stuff on the pool floor today. The CL level is still over 20 (and I'm keeping it there until the water is clear).

Today's plan of action:
1. Vacuum thoroughly (past attempts have been abbreviated due to the deluge of rain)
2. Change out the filters (it's nice to have the second set)
3. Check CL and add more bleach, if necessary. It's sunny today, so I expect I will need some.

Now that it appears we are in the home stretch (can I say that without jinxing myself?), would adding clarifier help or hurt? I don't want to take a step backwards.

Thanks a million!

Well, it appears I successfully jinxed myself. This stuff is resilient. After having read the debate back and forth on polyquat 60, I let the CL drop a little and put in 2 quarts the other evening to see if that would clear up the remaining "stuff". I can safely say that the quat did squat. In fact, the following morning there seemed to be more "stuff" than in previous mornings.

So back to the tried and true (yes, I should've listened better) of bleach and more bleach. We put in enough this morning to get back to the 25ppm we'd been running. I ran a test this evening to see if I needed to add more and, just for the fun of it, did a CYA test also. It came out at 50 (you keep going until you can't see ANY of the black dot, right?). How is this possible???? It had been testing regularly in the 80-90 range. The PH seems to have dropped a bit also, but not much.

TC - approx 25
PH - 7.3-7.4
CYA - 65
TA - 120

I am having a similar problem. I have shocked the pool and it stays free of yellowish brown powder which collects in the same spots of the liner each time until I turn on the filtration. (It poofs when swept and vaccuums easily). I have shocked and treated with yellow rid. The pool water is perfectly clear and the pool floor will stay clear for days UNTIL I turn the filtration system on. I too believe it is coming from jets. I have backwashed and rinsed and poured in the recommended amt. of filter cleaner. Could the filter sand need to be changed. If this residue is in the pipes how do I push it out?

We may be nearing the end of this thing. I've been keeping the CL at shock levels consistently for about 3-4 days now and vacuuming and cleaning cartridges religiously. One thing that I was forgetting was to brush (don't know how I missed that one), so I started that yesterday and what a difference today was. So little on the floor that I vacuumed again this morning and nothing has shown back up so far. I also replaced a ripped air relief screen in the filter. Not sure if that was contributing to any of the problem.

Anyway, for fun, here's our bleach container graveyard for the past few days :D -

http://www.cooltot.com/bleach1.JPG

I realize this is an old post but I have this same problem now. I had it in the fall, thought it was taken care of but IT"S BACK! So I guess I didn't really have it taken care of!

today:
I have brushed, vacuum and shocked to 15ppm
CC-O
CYA 45 (tested between 40-50)
PH 7.5
vinyl lined 18X36 inground

I'd like to know if I should go higher with the Chlorine,if so how much higher and for how long.

My pool has full sun all day, the CYA is usually higher, has dropped from 60 over the last few months.

I sure hate to see my Pool Solutions kit run out of components...it is the best!

Post your chlorine reading and then someone here can better advise you.

If it's powdery and yellow or mustard color, then it's likely to be yellow/mustard algae and that takes more chlorine to kill and to keep away. I would shock at a higher level 20-25 ppm FC and you can lower your pH some (say, to 7.2) before adding the chlorine since the large amount of chlorine will raise your pH (which makes it a little less effective). Keep the chlorine up until the powder is gone and does not reappear and keep brushing it so it mixes with the water and gets full exposure to the chlorine.

You probably had your CYA too high at 60 since that would mean needing to keep your FC at a minimum of about 7 ppm FC. If you maintain 30-40 ppm CYA, then you could keep a minimum of 5 ppm FC (maybe a little less) and probably keep this mustard/yellow algae away. Some users report that they need a higher chlorine level to keep the algae away -- roughly the Max level on Ben's chart or the 0.07 column in my chart while others are OK with the mid-levels or the 0.05 column.

Do you remember what your FC level was when this algae first appeared? That will help us confirm or adjust our recommendations.

Richard

As I posted... my chlorine reading was 15ppm last night
No CC ever

I checked this morning and it is still 15 ppm!

So maybe I have over reacted but this stuff sure looks funky. It is like a red dust, just like the photos at the beginning of the this thread.

It dissipates into a cloud when brushed. There is just a little bit of it this morning.

We have lost CYA via dumping excess water due to heavy rains and backflushing. We normally keep the CYA higher because we have full sun exposure ALL day and cannot keep chlorine. Keeping it higher has pretty much solved that problem. It may not work for everyone, but it works for our pool.
Thanks

Sorry - for some reason, I just didn't see where you had posted your chlorine reading. I'm gonna let ChemGeek help you with this. I'm actually out of town and just popping on to the forum on a laptop. Getting ready to head back to Charleston in a little bit. ChemGeek or somebody else will be around this afternoon and can give you some help. Good luck.

Well, if your chlorine is holding, then it isn't breaking anything more down and if the dust or algae or whatever it was is gone, then it is probably killed and filtered or broken down. If it was truly red (the pictures at the start of this forum look more green/yellow to me and that's more like mustard/yellow algae), then this could either be non-algae like dirt or could be a red algae (there is that type of algae, but it's usually not found in pools as far as I can tell).

Anyway, it does sound like you've solved your "red dust" problem. On the CYA amount, I am surprised that 60 ppm CYA makes that much of a difference compared to 30 ppm CYA. In theory, it would only increase the half-life of chlorine (in direct noontime sun) from around 6 hours to 7 hours which isn't that much of a difference. Of course, whatever works for you is what is best.

Let your chlorine drop to "normal" levels but keep it as suggested at around 6 ppm FC or so minimum (at your current 40-50 ppm CYA level) and see if this stuff returns. If it does, then you can try shocking to higher levels (20-25 ppm) as I mentioned in my earlier post.

Richard

Let your chlorine drop to "normal" levels but keep it as suggested at around 6 ppm FC or so minimum (at your current 40-50 ppm CYA level) and see if this stuff returns. If it does, then you can try shocking to higher levels (20-25 ppm) as I mentioned in my earlier post.

Richard[/QUOTE]

Hi Richard,
Just checked the chlorine after full day of sun and 80-85 degree weather here in NC.
FC has dropped by 5ppm since this morning. (Remember it held stable overnight at 15ppm)

Is it normal to lose that much chlorine in a day?

That does seem a bit high for a drop. Losing half of the chlorine over a day is more typical -- so 15 ppm to 7-8 ppm would be more "normal". Then again, I could be wrong about those half-life numbers. They seem to be correct for most pools, but there's no arguing whatever it is that you are seeing in your pool. It's also not like you are in south Florida or the middle of summer. Maybe there is in fact some algae in your pool and it is growing more during the day and consuming more chlorine, but typically if it holds overnight then this means the algae is gone. Sorry I don't have a good answer for you.

Richard

OK, I've been thinking more about this and I believe you do still have a chlorine demand with this (presumed) algae. It's probably a demand of 1 ppm per 8 hours or maybe a little more. That would "seem" like the chlorine holds overnight, but if you lose half from the sun 15-->7.5 and then another 2 or more from chlorine demand from the algae, then that would get you to 5.

So, I would suggest really hitting this algae with a lot of chlorine. Start with 30 ppm FC in the morning. If you are able to stick around and add more chlorine during mid-day, do that, otherwise add more when you get home at night. Keep this up until 1) there is no more visible red dust and 2) the chlorine holds solidly overnight (virtually no drop at all) and holds more during the day so it drops no more than half.

If that works, then the question becomes how to keep this algae away ongoing. Though you could maintain a minimum of 6 ppm FC at 45 ppm CYA (or 8-9 ppm FC at 60 ppm CYA) which is what some others have found is required to keep away mustard/yellow algae, there is another way that might let you keep lower chlorine levels. See this thread for the use of 30-50 ppm Borates in the pool which act as an algaecide (as well as an additional pH buffer). The problem is that we don't know if this is a good algaecide specifically against mustard/yellow algae though it does inhibit a variety of different algae. Anyway, I just wanted to give you a long-term option that might help since this is a repeated problem for your pool that would require higher chlorine levels to keep away (even at 30 ppm CYA, you might have to keep a minimum of 5 ppm FC to keep away mustard/yellow algae instead of the normal 3.5 ppm FC mid-point recommendation).

Richard

Hi Richard,

You are so kind to help me. I may have been unclear in the previous post about the loss I experienced. I started the day Sunday at 15ppm (it held overnight Saturday) and ended the day Sunday with 10ppm.. a 5ppm loss.

I added Bleach last night to bring it to 18ppm ( I also put one trichlor puck in the skimmer)and checked this afternoon. The chlorine is 14.5ppm. It was not as hot today, but sunny almost all day. I added another 96oz of 6% bleach (usually gives me 3ppm rise) a little bit ago. I know when the CYA was about 60, I did not have as big a drop daily. You did a survey last summer and asked me for my numbers ( I don't remember them now)

I am nearly positive this is some sort of dirt/pollen. It brushes away very easily, just the momentum of the water will disturb it. I cannot find anything on the walls or ladder. I have run my fingers under the ladder step and found nothing.

I am reluctant to add more stuff to my pool because one of my 4 legged children drinks out of it! I hate to even use algaecide, so I am not too sure about the borate....although I realize if we had city water it would be the same thing or close to it.


Mary Beth

The survey is at this thread (it was actually leejp that asked the question). Unfortunately, what was not asked for the table was the FC level when the additional chlorine was added. This is important because the absolute amount of chlorine that is lost through sunlight is proportional to the amount of free chlorine (FC) in the pool. If you have twice the FC level, you will lose twice as much chlorine.

Sorry I misinterpreted your numbers. Going from 15 ppm to 10 ppm (a 33% loss) is quite normal as is 18 ppm to 14.5 ppm (a 20% loss).

I hope you are right that it is just dirt or pollen. That certainly a lot easier to deal with!

As for your dog (I assume that's the 4-legged creature), the EPA reference limit for chlorine of 0.1 mg/kg/day so for a 10 kg (22 pound) dog that comes to a limit of 1.0 mg/day so at 15 ppm (mg/l) FC that is 67 ml or about 2.3 fluid ounces per day. This is the limit where there were no adverse side effects whatsoever -- it's not a limit for chronic toxicity which is much, much higher (14.4 mg/kg/day) -- and is worst when inhaled rather than drank. The fact that there is CYA in the pool probably doesn't matter at all since the chlorine will get released from the CYA as it is used in the body.

For boron (borates), in dogs at 0.44 mg/kg/day there was noticeable decrease in spleen to body weight in males, but that was the only effect and is the lowest dose with any known effect. Boron in humans actually has potential nutritional importance, at a requirement rate of around 0.75 kg/day with normal safe amounts of around 1-13 mg/day (this translates to around 0.015-0.2 mg/kg/day). So using the 0.44 mg/kg/day as a limit, then for a 10 kg dog this comes to a limit of 4.4 mg/day so at 50 ppm Borates (which is actually measured as ppm Boron by convention) that is 88 ml or 3.0 fluid ounces per day.

So the bottom line is that both the high chlorine level of 15 ppm and a 50 ppm Borates level are both a problem for dogs drinking regularly from a pool if they do that every day drinking, say, a cup or more every day and the technical limit below which there are no symptoms would be less than half a cup every day. I again want to stress that the amounts are for the lowest limits below which there are no symptoms or measured body changes (even after years of exposure at these levels).

City water, by the way, probably doesn't have any chlorine in it at all since most municipalities have switched to using monochloramine as the residual instead, mostly due to newer strict requirements at reducing the amount of disinfection by-products in drinking water. Also, if there was residual chlorine in the water, it is likely to be at very low levels less than 1 ppm FC. In fact, you can easily measure the FC level of your drinking water and if monochloramine is used instead, then your FC will measure near zero, but your Total Chlorine (TC) will measure high (since monochloramine measures as combined chlorine). There are usually no Borates (or Boron in any form) in drinking water.

Richard

Quote:

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Originally Posted by chem geek

So the bottom line is that both the high chlorine level of 15 ppm and a 50 ppm Borates level are both a problem for dogs drinking regularly from a pool if they do that every day drinking, say, a cup or more every day and the technical limit below which there are no symptoms would be less than half a cup every day.
Richard

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Thank you for posting that info. :) I'd been concerned about adding borates to my pool for exactly that reason, having remembered something I read a long time ago about boric acid being toxic to canines. I started to do some searching and was having some difficulty slogging through the chemistry - although it appeared that borates, and their chemical relatives, are NOT good for dogs at the level being considered for the pool. I had hoped to post a question about borates and canines after I could better understand the articles I was finding. Thankfully, I don't have to do that now!:)

I have a swimming pool fool (canine) that believes we constructed this wonderful outdoor water bowl specifically for her, so I'm certain she drinks more than a cup of water a day plus there's the amount that gets into her mouth as she splashes about and swims. She's approximately 55-60 pounds.

I guess we'll skip the borates and hope we don't have a repeat of the dreaded yellow/mustard algae this fall.

Thanks again for that info.

Sandy,

I don't want to needlessly worry you, but the point I was making was that the chlorine in the pool was also a problem, not just the Borates. Though I used the example of a high chlorine level of 15 ppm, a level of 5 ppm would also be a problem since the limit of no symptoms would be about 12 fluid ounces or a cup and a half per day for 22 pounds so for your dog it would be about 2.5 times that amount (so about 30 fluid ounces or 4 cups). And yes, your dog drinking more than a cup of water per day would exceed the "no symptoms" limit for Borates, but would also be closer to the "no symptoms" limit for chlorine. The Borates limit of "no symptoms" for your dog is around 8 fluid ounces or one cup per day.

Again, these are "no symptoms" limits, not limits for toxicity. Nevertheless, to the extent that you can try and restrain your dog from drinking a lot every single day from your pool, that would be better. Perhaps having a water dish nearby with an occasional treat present might wean her away, at least some of the time.

So, bottom line, you are right and probably safest to avoid the Borates if you can't keep your dog from drinking the pool water regularly.

Richard

Quote:

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Originally Posted by chem geek

Sandy,

I don't want to needlessly worry you, but the point I was making was that the chlorine in the pool was also a problem, not just the Borates.
Richard

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Needlessly worry me???? I worry about everything, so this is nothing new.:D
I'll watch my CL level too. Just glad for the info. :)

And, yes, I'll try an outdoor bowl to see if I can't interest her in quenching her outdoor thirst somewhere other than in the pool. Frankly, I think she gets a real kick out of submerging her muzzle and swishing it from side to side, blowing bubbles and biting at the water a bit. Yes, she's got some Lab in her "mix." :p

Dawndenise - in case your problem still exists and/or resurfaces over the next while, it's not pollen or dirt - read the sticky thread at the very top, there's only one way to kill that stuff and that is high FC (25-30) for an extended period of time (5-7 day) - even if your pool looks spotless after day 1, because it'll be back like a bad nightmare.....
I'll probably get blasted by someone for this, but I've helped cure enough people of this problematic stuff to make me feel 100% comfortable in stating the above, others haven't.

Dawndenise. Listen to Matt4x4! I agree with him. As far as the dogs go you CAN teach them not to drink from the pool. I have 3 and a cat who thought the pool was their own outiside water bowl also! It took a bit of time and a lot of patience :eek: but they have all learned that their water dish outside is for drinking, not the pool!:D I used a combination of a loud NO, a water pistol or a hand clap to stop them from drinking from the pool and then lead them to the water bowl and when they drank from it I would give them a treat. I kept ice in the water bowl so the water was cold and that helped also. The cat was the fastest learner. It just took a few loud NOs. Now he is content to just play with the Deck Jets when they are on. BTW, I DO have borates in my pool.

Matt...thanks for the info. Actually it was itstoohot that had the initial problem in this thread. I had just jumped in because there was, IMO, a very important point being made by ChemGeek that borates may pose a problem in pools where canines drink a lot of pool water. While borates appear to have many benefits, I don't believe that any posts prior to that one brought up the issue of companion animals and borates.

But, I AM glad you made a response because it allows me to thank you for your postings on mustard/yellow algae. I had a problem with it last September which I detailed here: http://www.poolforum.com/pf2/showthread.php?t=5921 and here: http://www.poolforum.com/pf2/showthread.php?t=5953 and it was your experience and previous postings along with ChemGeek's responses that got my pool cleared up. Without your postings, I would have never imagined I'd have to go to that high a level of chlorine to get rid of the stuff. :eek:

Hi Evan,

Guess we were posting at the same time. I'm glad to hear your animals are staying away from drinking your pool water with the borates. I may have to seriously think about re-training my gal to not drink from the pool if I ever hope to add borates and get out of the pH/TA cycle I'm currently in, but that's a post elsewhere.

Still, she's really a swimming/splashing/drinking fool....:D