Tried everything, still have green pool

Hi all, I am ready to drain my pool.

I came here in hopes someone might have some suggestions. The pool store is even stumped and I refuse to buy anything more from them at this time because I have spent over $300 on there chemicals in the past 2 weeks. I have a 27 ft round, 17,000 gallon above ground with a Hayward sand filter. I have well water.

My chlorine is off the chart on my accucheck with a reading of 10, because they told me to add a case of shock. It is holding this level for 2 days now. My pH is 7.4 alk is 110.


My phosphates were high so 2 weeks ago added bottle of remover.
I used terminex Algaecide with copper last Saturday they said 8 oz.
Been using DE powder in filter and backwashing 3 x a day.

Have tried iron remover, clarifier, just about everything..

Please help

More knowledgable people than I will have to give you specifics, but I suggest you add no more chemicals (other than to maintain enough chlorine for sanitation and to keep your ph in range) to your pool until you determine the problem (which probably can be done with help from Pool Doc or Chem Geek)... If your issue is metals (iron or copper), high chlorine will exascerbate the issue; if it's algae, your chlorine might be too low (depends on your cya level). Don't use any more of that algaecide... It contains copper. If copper is your problem, you are making it worse. If copper is not your problem, then you are potentially creating a new problem. I can also tell you that it will be difficult to troubleshoot your problem without a test kit... Taylor k2006 or k2006c (which simply has 2oz bottles of the same reagents).

Unfortunately, your problem is not uncommon. Fortunately, we're here.

1. Stop using everything the pool store can think of -- you may ALREADY have problems due to incompatible chemicals. Do NOT use any more algaecides, especially copper based ones.

2. Buy some DE powder -- a 10# bag is plenty -- and add a coffee can full to your skimmer, while the pump is running. Then, watch the inlet where water from the filter returns to the pool. If the return water gets cloudy with DE powder . . . your filter needs service. Most likely, it simply needs more sand. Fix this pronto; you will not be able clear an algae filled pool with a non-working filter.

But, if the DE does not return to the pool, that's great: the DE will help filter out fine algae particles that would otherwise go THROUGH the sand bed in the filter.

3. Purchase a cheap local OTO kit (yellow / red drops), and test your pool. You want your chlorine level in the DARK yellow range, above what the kit shows.

4. Read the "Best Guess" page -- linked in my blue signature block -- then go get a CYA test, so you can get a rough idea of what chlorine level you SHOULD be maintaining.

5. Go to the Test Kit info page (blue block again) and follow links to Amazon so you can get a K2006 kit, and find out what your CYA level actually is, and can measure the chlorine level you need. NOTE: So far as we know, K2006 kits are not sold locally, anywhere in the US. Pool dealers find it hard to get enthusiastic about product that replace them.

6. Post info on DE filter test results, OTO test results and current pool condition, once you have that info.

7. Run your filter 24/7 if you are not already doing so.

Thanks for the info, I went to the pool store again today with another sample.
free chlorine 4.2
total chlorine 6.64
Combined 2.37
ph 7.2
alk 88
copper 0
iron 0
nitrates 12
phosphates 100
cyanuric acid 27
calcium hardness 149
They looked at me in confusion...
He said wait I have a product in the back room that you can have to try although I have never used it. Ok so before I dump 45 lbs of this in my pool I want to know what anyone else thinks?
It is called endure ssodium tetraborate.

I have the DE powder and will give that a try. I have been putting in about 1/2 cup daily in the skimmer and backwashing daily.
I use test strips and the accu-check meter and also a basic yellow red compound test kit for ph and chlorine. Been running the filter non-stop for 2 weeks now.

Sodium tetraborate is borax.

You can use it -- doing so makes your pool less 'friendly' to algae -- but to reach an effective level, you need at least 30lbs more. You can buy it at Walmart as 20 Mule Team borax in 4.75 lbs boxes, so you'll need about 7 boxes. PLUS . . . borax is basic, with a pH a little above 9, so you'll need 4 - 5 gallons of muriatic acid.

Do NOT backwash, unless you see a pressure increase -- otherwise, you'll have a hard time removing the fine particles. When you do backwash, notice what color the backwash has -- if it's green, increase your chlorine levels a lot!

See if you can find an HTH 6-way kit at your local Walmart; if not please order a K2006. Test strip measurements of CYA are more often wrong than right -- and CYA level is a KEY factor in algae control.

Ok so here's an update. Didn't do the borax yet just been putting in great value bleach 2 gallons at a time twice a day. Its holding chlorine level at about 10. CYA is only 27? Ph is 7.6 alk is 112. Pool is still green but looks almost like its turning a blue green. Would like to post a picture but don't know how. Any advice on numbers? I back washed this morning after leaving it for 2 days. Color was deep green for about a minute. Thanks

How are you testing?

A reading like "alk=112 ppm" looks like a computer read test strip. Test strips do NOT allow accurate readings of chlorine, and provide horrendously inaccurate readings of CYA.

What is the OTO test result? Have you ordered a K2006 . . . or purchased a local HTH 6-way kit (contains the Taylor CYA test)?

If you've been adding 2 gallons 2x per day, on 17,000 gallon pool, and are still "blue-green", you need higher chlorine levels. Continue with the 2 gallons in the AM, but go to 4 gallons in the late PM . . . and TEST WITH OTO!!!!

A week later update:
Pool is finally blue with no sign of green anymore. I ordered the k2006 test kit but until then using the accu check strips and tester.
Pool is still very cloudy and I can not see the bottom. Anything I can do for this? Hasn't seemed to change at all even with adding 8oz of a clarifier called sparkle 3 days ago.
I have used a sock in the skimmer and also been using DE powder. Back wash every couple of days. I have not put in any more shock for 4 days now.
My numbers this morning were

ph 7.1
alk 122
chlorine 6.7

Used the 6 way strips and the cya looks like a light orange so not sure on a accurate reading there other than it looking low on the color chart.
I do have stabiliizer in a sock tied to the ladder.
Any suggestions for the cloudiness? Thanks

1. Don't backwash, till the pressure goes up.

2. If the pool is gray/blue with NO green, but still cloudy, it's a filtration problem, not a chlorine or algae problem. (DEAD algae is a filtration problem!)

3. Do go ahead and put 3 - 4 cups of DE in the filter. Do NOT backwash till you see a pressure increase, over the just backwashed pressure. If this does not happen after 2 - 3 days, post that info. (I'd really expect it, after 24 hours).

4. Make SURE the DE is not going back into the pool.

5. If you haven't already, add several gallons of bleach and then carefully brush the pool. There may be unseen pockets of algae that you need to expose and kill.