Green Pool

[Nick99]

Hello, newbie here. First time opening our pool, we move in last fall. Over two weeks now, we've tried all kinds of products, the water is still green.

Last week's test at the local pool store showed low pH (6.7) low calcium hardness and I can't recall the free and combine Chlorine numbers.

Yesterday I used this Costco product that supposedly clarifies, maintains pH etc, nothing, today I'm trying this SWAT product from the local store. I've backwashed and rinsed, good pressure from the returns and at the pump it seems. Still swampy green looking. I can only see about 2 feet max below the surface.

If anybody has suggestions, greatly appreciated. Thanks in advance!

[phil_p]

If you haven't changed out your filters, that may be a start. I had that problem and decided to drain my pool. Then I performed and acid wash. After that I painted it and filled it up again. The algae came back, so I cleaned out my sand filter (which was totally green with algae). I have since used a yellow out product from WalMart and some chlorine. There is also some "anti" algae liquid you can buy at Walmart.

So, try to change out sand first, then add the algae killer with chlorine. That would be easier than going thru all the stuff I did.

[phil_p]

I forgot to mention that there are several videos on youtube. Start with this one:

or use their search bar to look for the green pool or algae or clean pool filter, etc....

[chem geek]

1) Get yourself a proper test kit -- the Taylor K-2006 (not the K-2005).

2) I suspect your Cyanuric Acid (CYA) level may be high in which case a partial drain/refill will be needed to lower it.

3) Lower your pool's pH with acid to 7.2

4) Shock your pool with an elevated Free Chlorine (FC) level that is 40% of the CYA level and maintain that level. This high FC is why it is best to reduce the CYA level first since you'll have to do that eventually anyway. Remember that shocking is not a one-time thing. You MAINTAIN the high FC level by adding more chlorine as needed and in the first stages that may be frequently (several times the first day, less frequently after that perhaps twice a day then eventually once a day).

5) Run the filter 24/7 and if the pressure is already elevated, backwash it. You can add DE to the sand filter to improve filtration, though it will get removed with every backwash and need to get re-added. You don't add much -- probably 1-2 cups of DE total added 1/4 cup to 1/2 cup at a time by mixing in a bucket of water and slowly adding to the skimmer. You wait a couple of minutes then check the pressure on the sand filter and when it has risen at least one PSI you stop adding the DE.

6) You stop shocking and let the FC drop when you meet three criteria: 1) the pool is clear with no visible algae, 2) you measure <= 0.5 ppm Combined Chlorine (CC) and 3) you lose <= 1 ppm FC overnight when the sun is not on the pool.

[Nick99]

Thank you very much for your replies.

The CYA is actually low 3 or 4ppm where it should be 30+ according to the local pool testers range. The pH is 6.7 so I will need to raise that at some point. The guy who sold me the house did the sand in the filter last year, so that should be good. I might just try that DE stuff too, thanks. Meantime, I plan to get a test kit from Costco, and lots of bleach. I think I'd rather use liquid bleach than the granule stuff which is probaby overpriced anyway. Also, I guess I need stabilizer to raise CYA. At this point I'm seriously considering draining a lot of it and bringing in new clean water.

Thanks Wizard for those steps. Question: how often do I need to backwash? Is it a question of pressure? If so, I need to get a gauge which I do not seem to have on the pump. I do have a large glass 'sight' where I unscrew to get to the pump filter/trap. That consistently shows lots of turbulent water and the return jets are very strong.

If CYA very low, and pH low, is there any order to these steps? I'm thinking of first dumping lots of bleach in there overnight before the sun can neutralize the chlorine due to the CYA being too low to protect the chlorine

[Nick99]

Thank you very much for your replies.

The CYA is actually low 3 or 4ppm where it should be 30+ according to the local pool testers range. The pH is 6.7 so I will need to raise that at some point. The guy who sold me the house did the sand in the filter last year, so that should be good. I might just try that DE stuff too, thanks. Meantime, I plan to get a test kit from Costco, and lots of bleach. I think I'd rather use liquid bleach than the granule stuff which is probaby overpriced anyway. Also, I guess I need stabilizer to raise CYA. At this point I'm seriously considering draining a lot of it and bringing in new clean water.

Thanks Wizard for those steps. Question: how often do I need to backwash? Is it a question of pressure? If so, I need to get a gauge which I do not seem to have on the pump. I do have a large glass 'sight' where I unscrew to get to the pump filter/trap. That consistently shows lots of turbulent water and the return jets are very strong.

If CYA very low, and pH low, is there any order to these steps? I'm thinking of first dumping lots of bleach in there overnight before the sun can neutralize the chlorine due to the CYA being too low to protect the chlorine

[chem geek]

Get your own test kit. Pool store testing is notoriously inconsistent. If your CYA is truly that low, then your chlorine may drop quickly during the day, much more than overnight. If that is the case, then add some; otherwise, I wouldn't until you get your own kit. And yes, adding the chlorine at night will help if you truly have low CYA.

You don't backwash unless the pressure rises up by 8-10 psi over it's clean level.

[Nick99]

Thanks chem geek. I got my test kit. I have seen improvements in chemistry after putting about 3x5L of bleach 3 different times this weekend. I also put 2 boxes of mule 20 borax, I forget the weight, and about 3kg of baking soda, not to mention a couple kg of stabilizer in socks by the returns to dissolve properly.

It is still quite cloudy albeit not as green, more blue, here are some readings: FC 0.5 (used to be 0), TC 1, Alk 80, pH 6.8 (it went over 7 at one point), TH 100 (not sure what I need to increase this; is there a household product with CaCl?), CYA 30-50 (it was close to 0 when I started).

Questions: what now? Do I continue to dump bleach? Can I backwash? (haven't done so in 48 hours or more according to the pool guys instructions not to do so for 48 hours when putting Stab in)

More borax? I love that stuff btw, so old school. I may look to get some borate strips to test that too. But for now my big concern is cloudiness and improving some tests like CYA, FC, pH.

I plan to post a pic of the pool colour at some point.

Thanks again!

[chem geek]

Yes, you continue to add bleach and you should be doing that frequently, if needed, to MAINTAIN a shock level of chlorine which for 30-50 ppm would be 12-20 ppm FC. You really, really need to get a Taylor K-2006 test kit since test strips can be notoriously bad especially for measuring CYA levels -- you say you got your test kit, so why did you report CYA as 30-50 ppm or did you not test with your new kit yet? You do not just add chlorine once -- you keep adding it to maintain a high FC level. Otherwise, the algae will just grow back and you'll never clear your pool. You have to keep the FC high to kill off all the algae and to oxidize some of it (the rest gets filtered out).

Do NOT add any more baking soda to the pool. 80 ppm TA is plenty high enough. If your pH did go above 7 at one point but is at 6.8 now, then when you add the bleach the pH will rise so just do that and you can deal with the pH later after you are done shocking.

As for backwashing, wait until your filter pressure has risen 3-5 psi from it's baseline level. Having some material in the filter helps it to filter better, up to a point. Run your filter 24/7 since even after the algae is killed by chlorine, clearing the pool is mostly about circulation/filtration/backwashing. Later on when your backwashing doesn't show a lot of crud and if your pool is still cloudy, you can add some DE to your sand filter. You note your starting PSI and then add about 1/4 cup of DE to your skimmer at a time until you see a 1 PSI rise in pressure (after waiting a couple of minutes after you've added the DE). Usually it takes 1-2 cups of DE total before you see that rise. You need to watch the filter pressure over the next 24 hours since it may rise a lot since DE will catch a lot of fine particles so you may need to backwash. If you do, then you'll need to add DE again unless your pool is crystal clear at that point.

[Nick99]

Not sure I understand your question chem geek, the first test was at the pools store, but I bought HTH 6-way test strips at WalMart and the first few times measured low FC, TC and CYA.

Today, good news: FC 10, TC 10, Alk 80, pH 7.2, TH 100, CYA 30-50. Most tests good.

I brushed it all and did a backwash. Now, I hope FC, TC and CYA hold overnight. I understand it could take a week or so before it becomes clear. I don't think I want to play around with the filter to add DE unless it is pretty easy. How does one open the filter anyway?

Meantime, to speed things up, is it a good idea if I use some clarifier/algaecide from WalMart? Any household products that can substitute? Any household product for Ca hardness, ie. CaCl? I love the BBB (borax, bleach, baking soda) approach. Maybe some more borax as I understand it has good algaestatic properties.

Thanks again chem geek. Any tips from here on always appreciated.

[chem geek]

The DE is easy. You don't need to get into the filter. You add the DE through the skimmer. Anyway, it just speeds up the clearing. I wouldn't use clarifiers. They don't always work and are really only needed when you've got cloudiness that is extremely fine (like a colloid; phosphate removers sometimes need clarifiers due to their very fine precipitate).

Chlorine alone if MAINTAINED at shock level will kill the algae and help clear the pool, along with good circulation/filtration. However, your HTH test strips don't test chlorine above 10 ppm and it doesn't measure CYA that accurately and doesn't measure calcium hardness at all (it only measures Total Hardness). You really, really should get a better test kit. Accurate testing is key. The Taylor K-2006 has a FAS-DPD test kit where you "count the drops" to determine the chlorine level which you can do with 0.5 ppm or even 0.2 ppm accuracy and it won't bleach out at high chlorine levels so you can measure even up to 50 ppm if needed.

I repeat, get yourself the Taylor K-2006 test kit now (be careful: not the K-2005; you most likely will need to get the K-2006 online). Test strips are generally terrible, especially for some of the tests.

[Nick99]

Thanks chem geek. I think that's more than I want to spend on a test kit. At a push I'll go back for a free test at the pool store. But I think I will get some DE and put it in the skimmer as instructed. Anything special I need to know when adding DE? Do I backwash before? after? not at all?

Any idea how I can attach a photo of my pool?

[chem geek]

The Taylor K-2006 is $50 from Amazon, Amato Industries and TFTestkits. It is absolutely worth every penny. It amazes me how people can have a $10,000-$100,000 pool or a $2000-$10,000 spa and not maintain it with a proper test kit. I repeat that your test strips are next to useless. I repeat, pool stores often do not test accurately.

As for the DE, you don't backwash before. The DE just acts like additional material added to the sand to capture finer material. You backwash after the pressure has risen 3-5 psi from its baseline level (i.e. the level before you added the DE).

[jkusmier]

The best advice I received from this forum came some 5+ years ago: buy a good test kit and learn how to use it. Taylor has a huge market share, and their kits are used in countless municipal water treatment plants and commercial pools. You can't solve a problem unless you know precisely what the problem is, and you simply won't be able to identify the problem by using test strips or taking a sample to your local pool store. Once you understand basic pool chemistry and use a good test kit, you'll find yourself spending less and less time and money on water maintenance and more time enjoying your pool. Study this forum and invest in a K-2006 - it will pay for itself in terms of money, time and frustration very quickly - and for years to come.

[Nick99]

You have to realize these things cost 2-3x more in Canada if you can even find them. This is my first pool, just trying to figure out what to do without breaking the bank.

Anyway, let's assume the test strips I bought are not totally useless. Nobody I know has the test kit you're recommending but they have no problems with their pool.

I backwashed yesterday and the FC and TC are lower (5 vs 10), still above the OK range indicated on the chart. The water seems bluer throughout but still cloudy. Any other steps? What causes cloudiness, is it only algae? What is used to raise Ca hardness or total hardness. pH is on the low end, maybe even 6.8 or 7

Anybody know how I can upload a photo on this forum?

[Nick99]

Latest readings

FC 3

TC 3-5

Alk 120 (steady)

pH 8.4 first time it's too high

TH 100 (steady)

CYA 0 first time in 2 days it's so low

Any idea where I can get product to raise Ca hardness? Is CaCl like ice melter good? Or am I forced to go the pool store which I want to avoid if possible.

[chem geek]

I'm sorry I forgot you are in Canada. You are right that in Canada you would need to get the Taylor K-2006 from Apollo Pools (Piscines Apollo) for $123. On another forum that is the largest for swimming pools, there are over 26,000 visitors to the site from Canada per month and over 2,000 registered members on the forum from Canada and most do use this test kit and properly manage their pools. Yes, you can get lucky and you can spend more money on algaecides, phosphate removers, clarifiers, flocculants, enzymes and other products if you want, but you can pretty much use chlorinating liquid or bleach at lower cost.

If it's cloudy, but no longer green, then the algae is likely killed off and the way to clear the pool is through circulation/flocculation. By the way, if your CYA were truly 0, then you would lose up to half the FC per hour during noontime sun so clearly your test strips are useless (but we already knew that). I don't know what to say. I can't tell you how much to raise the FC since we don't know the true CYA level. To be safe I suppose you could raise and MAINTAIN it at 10 ppm FC until the pool gets more clear. If you get impatient, then you could use a good clarifier (GLB Clear Blue and Bioguard Polysheen Blue are good clarifiers; OMNI Liquid Floc Plus is a good flocculant). If you do use a clarifier, backwash out the DE first or else you can get a gummy mess that may not backwash well.

As for calcium hardness, yes Calcium Chloride from a quality ice melt product such as Peladow or Dowflake is fine to use. However, do you have a plaster pool? If instead you have a vinyl pool, then you don't need Calcium Hardness (CH) to protect it. If you have fiberglass, then some CH may be helpful, say 150 ppm, but probably not necessary to have it as high as with a plaster pool.

[Nick99]

Oh, so for vinyl liners, CH hardness not critical? Did not know that. I'll check to see what kind of liner it is. I already ordered a 50lb bag of Excel CaCl pellets from my local Fastenal, for less than $30, but it will find a good use in the Canuck winter, at the very least.

I'll try to get the Taylor kit from my brother visiting the States, hoping Sam's Club or Wal-Mart and the like sell them.

Pretty impatient as we want to use the pool this weekend, so we might go with some clarifier, thanks for the recommendations.

Thanks again, and I will make sure to backwash before the clarifier, and even try to use some DE as you previously instructed.

[chem geek]

No, Sam's Club, Wal-Mart and the like do not stock the Taylor K-2006. You can get the HTH 6-way kit at Walmart that is at least a drop-based kit that tests for everything, but it's a DPD chlorine test not FAS-DPD so only goes up to 5 ppm accurately and has rather low resolution, especially for distinguishing Combined Chlorine (CC).