New house, old pool, yellow dust won't go away

Ruined

Member
Aug 20, 2012
19
Hi all,
First post here looking for some help. I want to verify the best thing to do given my situation, hope I could get some feedback.

Background:
1) Approx 30k gallon kidney pool - sylvan from 70s, two skimmers. Water about 1.5" higher on one end than the other.
2) 70s hayward sand filter. I suspect sand has not been changed in a while as pressure never goes up beyond 15.
3) Inground
4) White plaster
5) Unknown flow rate of filter. It has been pressure tested and is okay. Though, the skimmers seem to be a bit weak in their suction.

So, to summarize, I bought a house in March. The backyard was a disaster, though I had the pool evaluated and it was mostly okay except a few things - some missing tiles, surface kinda rough, wiring is old, filter old, above ground plumbing had wrong type of valves and air leak. Buyer did not have much info on the pool other than he actively used it and used a "slime bag" attached to the filter, which is a huge white sock looking thing; I assume it was not filtering well for him.

Anyway, I had a limited amount of money to fix the backyard. As the area around the pool was a mess and dangerous (cracked and misaligned concrete), I spent most of the money redoing the area with pavers. I must also note that when they were doing the backyard, the pool water did turn dark green as it was not running - alot of wind etc from all the paver cuts got in the water and it was suspected the lime had a chemical reaction; the contracts drained the pool and watered down the surface. It was then refilled and appropriate chemicals added per pool store, but surface appeared to retain some lime stain which store sold me pool stain treat to use on... I never got around to doing that though due to other problems you will read about below. Some addt'l money was spent on the pool, such as repairing tiling, new coping, and replacement of above-ground plumbing/valves. Some mortar got in the pool when the tile was repaired and it took a long time to get it out.

There is no longer an air leak, coping looks nice, tiling is reparied.

I have struggled with the chemicals, though I did start off the season by taking the water to a pool store and buying chems. Now I have a good kit and have been keeping levels acceptable across the board - not just chlorine and ph like my dad showed me, but also alkalinity, CYA, etc. I have a taylor DPD test kit which works really well (tests same as pool store). I got an aquabot too because I could not find an adapter for a manual vacuum plate for the skimmers and just jamming a hose in the skimmer did not generate enough suction, not to mention the nonstop debris.

So here is the problem

The pool is beautiful, but it backs up to a forest. There is one tree partially over hanging it, and wind blows up the hill - blowing leaves into the pool constantly. Some are filtered into the skimmer, but probably 50% just sink.

So there is constantly some sort of leaf debris in the pool. I run aquabot for 6hr 1-2x a week and filter at least 8-12hrs a day, I brush 2-3x a week. There is still little bits and pieces of leaves on the pool floor. Not a ton, but enough.

Over the past month, I have been noticing an increasing yellowish dust/dirt on the pool floor and walls (everywhere). Note that the water can be sparkling blue, with this ugly yellow dust on the wall. I can sweep it away, but it returns in like 2-3 days. Even if I shock the pool, it can literally return in a day. One time there was a lot of it and the water was blue, but after I brushed it all off the walls the water turned emerald green (mostly translucent). I will also say at this same point the chlorine had dropped to 0.2 (even though there was still chlorine in the floating dispenser, I believe I accidently had it set to distribute too little when I added it). In addition, I did not know shock was supposed to be added every week so this probably added to the problem.

This yellow dust covers the ENTIRE pool bottom and walls. It seems worse by the stairs, behind the ladder, and in the shallow section. This may be a function of me dumping most of the chemicals into the deep end, or something else. The stairs get a lot of sunlight as does most of the shallow end, though the area behind the ladder gets less.

So first, is the problem:
-mustard algae?
-pollen?
-dirt?
-malfunctioning filter?
-old sand?
-just regular dirt/debris from leaves that looks extra bad on white plaster?

Second, these are the chemicals I've tried:
-bioguard burnout3, 3bags/wk (and other calcium hypochlorite shock)
-kemtek quick shock (trichlor, got off amazon - probably won't use this again because its odor makes me unable to breathe).
-Bioguard BackUp (which I believe is a quat)
-Kem Tek Ultra Clarifier (needed this at one point).

My last big effort to combat the dust was do the following:
day1 - brush all dust away; balance ph, add 6lbs of shock; add initial dose of BIOGUARD BACKUP; 2 tabs of chlorine in skimmers and fill chlorinator; filter
day2 - add 3lbs additional shock; run aquabot; filter
day3 - filter
day4 - run aquabot
since then - check chemicals every other day

Had to also add a clarifier.

Obviously the best thing to do would be to get a pool pro to do a thorough testing and evaluation of everything, replace sand & possibly filter, trim the trees, possibly get a solar cover to prevent debris... but I am short on cash now with all of the money spent on the new house and renovations it needed. It is also approaching the end of the season. I have recently spent $300+ in chemicals which I have blown through and here I am with the yellow dust remaining.

Can anyone give me some tips what the best course is to go now?? Thanks much!
 
Sorry to hear you stuggling and still have a mess after several hundreds in chemicals.
I am by no means an expert on pools but I just wanted to let you know my story.
I had a inground built 5 years ago and strickly used biogaurd chemicals. Since the middle of last summer I have struggled to keep my pool clean. always cloudy, always looked dusty. I spent hundreds of dollars at the pool store and tried everything they suggested.
2 weeks ago I came on this site and switched my pool to the BBB method. 3 days later my pool was crystal clear and has been ever since. It hasnt been this clear in almost 2 years.
Read Pool school and then read it again.
ask alot of questions
follow the advice given on this website by all these great people. (my CYA was 160 from the chlorine tabs I was using so I had to dump 1/2 my water and refill)
Invest in a test kit with fas dpd.. It will help ALOT in the shocking process
It works and It only took me 24 $$ in bleach to get a clean pool. I have not added anything other than bleach in 2 weeks and have had no problems (I have a woods right behind my pool)
Good Luck.
 
Welcome to the forum. :lol: As you continue to read, you will find that virtually every piece of meaningful advice on pool water chemistry has to start with test results. Could you use that K-2005 test kit and post a complete set of results? That'll help us get started.
 
I just threw in a heap of shock so it will be off now, but I can give you my results from this past Saturday:

Free Chlorine - 5ppm
pH - 7.4
Alkalinity - 150
CYA - 40


One other thing I failed to mention, when I threw in the 9lbs of shock about 1.5wk ago the FC level was >10ppm for 2 days, put all the equip in the pool to sanitize it as well. Will have to read up on BBB method, though I have seen others swearing by plain clorox bleach if thats what it is. Any side effect to using clorox (i.e. other ingredients in it?)

also I just ordered some Kem Tek 60% poly quat, I figured this would be part of the next step if it is in fact algae as the standard quat did not work... i also did not describe the yellow color, it is a light yellow that gradually progresses to a darker yellow if not brushed for a few days, when brushed it ranges in color from looking like dirt to like egg yolk and is EXTREMELY easy to 100% brush off just like it was dust. If it is algae, though, I was surprised it survived the 9lbs of shock + BackUp treatment plus equip sanitization/brushing/vaccuuming. I also did not clean my filter basket as I sort of forgot about it as I was just emptying the skimmer baskets - the filter basket though had built up a MASSIVE amount of leaf bits (like it was stuffed with them) which I did clean out before doing the 9lb shock treatment.
 
Welcome to TFP!

Sounds like algae. It's tough to treat though unless you can get dependable test results.

If your CYA is 40, then your FC needs to be 16 in order to shock your pool. Can your test kit tell you what your FC level is above 5 ppm? If you have a Taylor K-2005, it won't. Therefore, you really need a better kit. Please visit tftestkits.net to purchase a test kit such as the TF-100 or Taylor K-2006.

Until you can test what you need to test, you are gonna be spinning your wheels really. Adding a little bit of this and a bunch of that without knowing how they affect your water or the values of such additions is really expensive, wasteful, and it need not be. You are a test kit away from pool bliss. :)

BTW, don't buy any more algaecide. You need chlorine, not algaecide.
 
Ruined said:
I just threw in a heap of shock so it will be off now, but I can give you my results from this past Saturday:

Free Chlorine - 5ppm
pH - 7.4
Alkalinity - 150
CYA - 40


One other thing I failed to mention, when I threw in the 9lbs of shock about 1.5wk ago the FC level was >10ppm for 2 days, put all the equip in the pool to sanitize it as well. Will have to read up on BBB method, though I have seen others swearing by plain clorox bleach if thats what it is. Any side effect to using clorox (i.e. other ingredients in it?)

also I just ordered some Kem Tek 60% poly quat, I figured this would be part of the next step if it is in fact algae as the standard quat did not work... i also did not describe the yellow color, it is a light yellow that gradually progresses to a darker yellow if not brushed for a few days, when brushed it ranges in color from looking like dirt to like egg yolk and is EXTREMELY easy to 100% brush off just like it was dust. If it is algae, though, I was surprised it survived the 9lbs of shock + BackUp treatment plus equip sanitization/brushing/vaccuuming. I also did not clean my filter basket as I sort of forgot about it as I was just emptying the skimmer baskets - the filter basket though had built up a MASSIVE amount of leaf bits (like it was stuffed with them) which I did clean out before doing the 9lb shock treatment.

assuming your tests are accurate you will only need liquid chlorine (i.e. bleach/clorox). Some people have used as many as 72 bottles of bleach clearing a swamp. But since yours is not really a swamp it will hopefully be less.

As a prior poster alluded shocking is a process not a chemical. During this process you need to keep your chlorine at the correct level for your CYA. In your case assuming your CYA is actually 40, your FC needs to be above 16 at all times. This means you will likely need to raise it above 16 so that when the FC is used up killing the algae it doesnt drop below 16. You may need to add chlorine every hour at first.

You are not done shocking until

1) you do the overnight chlorine loss test and lose less than 1ppm of FC
2) your combined chlorine is less than .5
3) your pool is clear (no algae or algae dust)

pretty much every thing you have bought is not necessary to clear your pool.
 
257WbyMag said:
Welcome to TFP!

Sounds like algae. It's tough to treat though unless you can get dependable test results.

If your CYA is 40, then your FC needs to be 16 in order to shock your pool. Can your test kit tell you what your FC level is above 5 ppm? If you have a Taylor K-2005, it won't. Therefore, you really need a better kit. Please visit tftestkits.net to purchase a test kit such as the TF-100 or Taylor K-2006.

Until you can test what you need to test, you are gonna be spinning your wheels really. Adding a little bit of this and a bunch of that without knowing how they affect your water or the values of such additions is really expensive, wasteful, and it need not be. You are a test kit away from pool bliss. :)

BTW, don't buy any more algaecide. You need chlorine, not algaecide.

I have a K-2006, yeah I have measured 10+ppm with it before. I wasn't sure at first but now i'm pretty sure its algae too. Unfortunately my last shock yesterday I used Trichlor so my CYA is likely higher now, will have to retest tomorrow.

Here is a question to both of you. So lets say I get the Chlorine to 16, or even 20 if needed using bleech (depending on my CYA) - isnt over 10 a significantly toxic level of Chlorine? How do I empty skimmers, vaccuum, etc without my hand melting off and whatnot? :) Then once I hold that for two days, how do I get it back to a normal level? Thx.
 
No worries -- you will not melt at those chlorine levels! It's actually safe to swim just below shock values. CYA buffers chlorine, so the net effective amount of chlorine you're dealing with is in the neighborhood of drinking water. That said, we also don't use the "more is better" theory of calculation, because liners CAN bleach at high enough concentrations, etc. So in a typical shocking process, one might target to 20 to keep the level above the 16 ppm shock level for a few hours without hourly babysitting, but not to 50 ppm to avoid having to check it all day.

Please read through the shocking instructions in pool school and you'll be on your way to a sparkly pool.

Re leaves - I deal with a lot, and use a leaf net for many of them. You can also position your ypjets upward to try to create a venturi effect and drive the leaves to the skimmer before they sink -- that works pretty well for me, but my pool is Grecian/octagonal. There is also something you can buy called pool skim that attaches to an eyelet and when positioned correctly, can catch the leaves as the float by, again, getting them before they hit bottom. Reducing the amount of organic debris that languishes will help your chlorine focus on the real enemy: algae ;)

To that end, can you post pictures of what you suspect is mustard algae? It's not that we can necessarily tell whether it's algae or pollen -- but eventually, when you conquer it, it would help other folks know what it looks like. It sounds like it's showing up on the shady side of the pool, right? Which is a characteristic, I believe, of mustard algae.

What does it feel like if you touch it?
 
Ruined,

It sounds like you are on track to getting cleared up. All good advice above....particularly about not wasting money on algacide....chlorine will do the trick.

Newbies frequently are concerned about the high levels of chlorine we suggest. The entire pool industry simply ignores the buffering effect of your CYA which makes these higher levels completely harmless.

Another example I like to use is your washing machine which in a normal load of whites contains around 250ppm FC with absolutely no CYA and yet is completely harmless to your skin.

Keep reading up in Pool School. "The ABC's of Pool Water Chemistry" up in Pool School and "How to Shock Your Pool" will be particularly helpful.

Do you have the K-2006 kit or the K-2005?
 

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Some great advice here, thanks all.

First off, yeah I have the Taylor K2006 with the DPD chlorine test. I got the kit a while ago but haven't mastered it until recently. If I got this kit earlier on and mastered it instead of using the el-cheapo brand I probably would not have this algae problem.

So another thing, I have an underwater pool light. How much of my success depends on the disassembly and cleaning of the inside of the light? Reason I say is because I have never done it before and inheriting the pool I don't even know if it is wired properly as it does not work (it does not even have a proper light box currently, just some capped wires sticking out where the broken diving board used to be), I am a bit wary of taking it apart. Can I do the process without brushing the inside of the light cover or will this definitely result in failure? I know mustard algae can re-contaminate, but will the chlorine kill what residue is left inside the light? I wouldn't mind an extra few gallons of bleach if it meant not having to take the light apart.

Regarding the leaves, so it is normal for a great deal of them to sink - I was worried the filtering system was shot. I would prefer not to use any additional contraptions as often they are gimmicks but if one really works I am all ears. I saw the pool skim and it looks like it could be promising, has anyone here actually used it?

Another questions - JUST FOR BACKUP, in addition to the bleach could I also keep chlorine pucks in the skimmer as well as a weekly dose of polyquat 60? I already have all of these chemicals so its not like I'd be spending any additional money to use them. The BBB method looks great but I think I'd want a backup in case I cannot manage the pool a day or two. And, my pool is like organic bacterial heaven thanks to the trees.

I am also wondering if at this point after killing the algae should I just close the pool? In my area (Northern NJ) there's not much left in the season... By the time this is sorted out it will be time to throw the cover on I think. Anyone have a resource for good value covers? The old one was damaged and thrown away.

Last thing, there are so many leaves that I never really get them all out of the skimmer baskets. There is always a coating of leaf bits on the bottom, even blasting them with a hose generally they get stuck. Tried skimmer socks but they made the skimmers float, plus I'd probably have similar problem. If I used the bleach method would these particles cause any issue?
 
Hi there -- I'm only going to address parts of your post, because for some of the questions, I simply am not sure/don't have enough experience.

1. I was afraid to remove my light in foreclosure swamp, but the water was cold, it was spring, and I did not get algae back once clearing. I predict folks with active warm-weather algae history under their belts will tell you that you should suck it up and remove the light so that the disinfectant can even GET behind there to sanitize. Just a hunch ;)

2. Leaves sinking is normal, particularly if there are great periods of time where you're not running the skimmer/filter. However, by turning my jets up AND running my filter all day, I only get 1 or 2 that might get to the bottom, and a full basket in the skimmer daily. If the water is 'moving' then the leaf will normally float long enough to get to skimmer (IF you've set the outlets that way...takes some trial and error.)

3. For pool skim, use the search box. Several people have reported here on this bulletin board happiness with the product. I have not (yet) used it because I did not want to reduce capacity on other eyelets and have "dead" spots in corner if I didn't need to...because of octagonal shape. I may change my mind once the leaves start to fall! ;)

4. If you keep pucks in the skimmer, you will be adding CYA. You do not want a higher CYA level if possible, because that will increase how much bleach you need in order to "truly" sanitize despite the buffer. So you can, if you feel that's the only way to maintain chlorine, but you'll want to keep tack how much CYA is added, and you need to realize that you could be creating a future problem (where chlorine levels are not effective). Polyquat is supposed to be the good one -- note that it may increase your chlorine demand slightly. But truly, chlorine alone should nail it. In which case, save the polyquat 60 for your closing, when you'll really need it ;)

5. I guess that will depend on when you get clear combined with the weather. I am in Michigan and I suspect I won't close that early because as soon as you get an unseasonably warm day, the conditions are ripe to breed algae. In general, I believe folks recommend to wait until the water temp is consistently 60 degrees.

6. Leaf bits in skimmer basket -- no problem really. Sometimes I'll give them a little brushing with a dishwasher type brush -- helps get rid of the debris. Pump basket is, to my mind, the more important one to get clean so that junk doesn't break free and jam up the impeller (especially maple keys and pine needles!). Skimmer basket...some days I can't even get the organic bits of bugs, caterpillars, worms etc. out of the plastic grids ;) Doesn't seem to matter.
 
Added 1250oz of bleach. Could not remove light as don't even know which breaker it is on, if it is live or not, and if it is wired properly. Will test tonight and see how it goes level-wise.

Quick question, with pool rafts, can I scrub them down with a something like Lysol? I only ask because simply throwing them in the pool will not cover all surfaces of the raft. Thx :)
 
First morning test 25ppm. Looks like it wasn't fully mixed last night when I tested it, which is understandable.

Here is a question, though - when brushing this morning I hit some patches that may have been missed yesterday,and while brushing them I got some yellowish/orangish dust clouds. Is it normal for algae to be able to survive in 20+ppm overnight and still give those colored clouds when brushing?
 
day 1:
reading 10:30pm: 22ppm (probably did not have enough time to mix)

day 2,
reading 9am: 25ppm
reading 6pm: 16.5ppm

added another 4 gallons of bleach.

Overall things going well except I'm having trouble brushing due to the chlorine smell which is irritating my lungs. :(

After the testing tonight and tomrrow morning, I don't think I'm going to keep it so high friday, maybe back off to 20ppm. Based on my CYA though it seems that i need 20-25ppm in there from the mustard algae index.
 
That chlorine smell is a sign you are killing stuff...it is CCs.

poolcalculator.com gives me a shocking level of 15 pmm for 40 ppm cya...so as long as you stay at/above that you should be making progress.
 
linen said:
That chlorine smell is a sign you are killing stuff...it is CCs.

poolcalculator.com gives me a shocking level of 15 pmm for 40 ppm cya...so as long as you stay at/above that you should be making progress.

BTW, poolcalculator is amazingly accurate. I wanted to get it back up to 25 earlier in the evening, so I added what should be the right amount from poolcalculator and it hit 25 on the nose!

Anyway, this was the chart I was referencing:
chlorine-cya-chart-t2346.html

This one says mustard algae shock level is 23.8 for 40 CYA. The CYA measurement I did with the taylor kit was around 35-45 though I'm not exactly sure what as its a difficult test to measure IMO.

I was thinking of throwing in a bit of PH down because the ph was closer to 7.4 than 7.2 when i started... although at the chlorine amounts I'm at maybe it doesnt matter.

Any recommendations to clean pool floats with? or should I de-inflate them and try to submerge for a few hours? Will this level of shock discolor the floats? And how dangerous is 25ppm @ 40CYA to humans? Not that I'm going to swim in it, but just handling of equipment and maintenance etc while its sanitizing... I've been using latex gloves.
 
Hi there. You can't trust your ph reading when chlorine is above 10, so I wouldn't bother til you're finished with shocking.

No worries about that level of chlorine -- it's minute. The other day I think it was duraleigh who mentioned that in a washing machine, bleach is 250 ppm ;)

For pool stuff, in your shoes, I might just fill up a tub or wheelbarrow, add more chlorine than the pool, and give them a bath and rinse. That's what they do at daycares. You could also mix bleach with water and spray them, then rinse. For my pool tools, I keep the leaf rake, skimmer, portable fountain etc in plastic tubs and add bleach to the water.
 

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