Pool being stubborn--green, high pH, no chlorine after daily work--HELP please

[BethL]

Hi everyone! I know this is probably a common one, but I can't access other posts yet. We have a 18x24 oval above ground, 4ft. deep. (by my calculation around 10,000 gal) It has a 1.5 hp Power Flow pump w Hayward sand filter. the pump is actually new because the old one sounded like it had bad bearings and then went *poof* on us. The pool stayed nice early in the season, when it was too cool to swim. Then it got hot and was still ok for awhile. We had a busy spell and realized no one had run the pump or added chlorine for about three days and by then it was green and nasty. I battled it, adding pH reducer and chlorine, shocking every two days, etc and it would only get marginally better. We replaced the sand about three weeks ago because the woman at the local hardware store where we get supplies told us that should be done 2-3 times a season--my online research has so far contradicted this. I am also now seeing that I should not be backwashing as often as I had originally been told. My cyanuric acid reading is zero so I've added four pounds this week alone...still read zero this morning. The pH is almost always high; actually today and yesterday it is getting in range but the total alkalinity is still all the way blue on dipstick. I shocked it again today. I'm using stabilized tabs starting about five days ago, was previously using liquid chlorine. the algae controller I have says to use it to prevent algae and that I should get the pool clean first. I have tried using clarifier maybe three times in the last three weeks because even when I have a spell of a couple days where the green goes away, it's still cloudy. We spent 250 on an automatic pool-bot and vac it every week. the pump runs almost nonstop and has only been turned off for maybe three or four hours at a time, maybe three times all month. I'm out of ideas and out of patience. We've only gotten to use this pool maybe ten times all summer! Should I give up and call in a pro? I am using cheap Walmart chemicals, if that's relevant, and it's still costing $100 a month. Ideas please?

[Watermom]

Hi Beth and welcome to the Pool Forum!

The first thing we need is some actual testing numbers taken with a drops-based kit. Test strips are pretty useless. We recommend that everyone have a good test kit. The one we suggest is the Taylor K-2006 or 2006C (same kit, bigger bottles of reagents and actually a better deal). You can get it through the Amazon link in my signature below. If the seller listed is not Amato Industries, wait a day or two until they restock. Some of the other sellers are sometimes sending the K-2005 by mistake which you do not want.

For now, go to Walmart and pick up a cheap OTO/Phenol Red kit (yellow and red drops). If you have a reputable pool store nearby, let them test the CYA level for you but don't let them talk you into buying anything else.

Tell us exactly what all you have put in the pool meaning ingredients, not product names. Also, post some numbers and somebody here will try and help you clear this up.

BTW -- Changing sand 2-3 times per season? That is ridiculous. Actually you seldom need to ever change it. Most of the mods have had the same sand for over 10 years. This is my 11th year with mine.

[BethL]

Hi thanks for the reply. I will get one of the bottle kits then—will they stay good over winter if I don’t use them all this year?
The pH reducer I’m using is 92% sodium bisulfate. I’m adding, on average, 32 oz. daily about five times per week. I don’t have the liquid chlorine bottle anymore, but I remember it was 1.5 times the strength of regular laundry bleach. Now I have the 1” dual action tabs—93.5% trichloro -triazinetrione and 1.5% copper sulfate pentahydrate. I use the HTH Super Shock n Swim 1# bags (recommended dosage is 1 lb. per 12000 and I use the whole bag).
What really frustrates me is my older neighbor, who only uses his pool about three hours a week just dumps a couple of jugs of dollar store bleach in his pool, never checks anything else and his pool has never been green. Makes me feel like a fool, lol. Any reason why I shouldn’t ditch all the other stuff and follow his lead?

[aylad]

Your neighbor has been very lucky, but I certainly wouldn't follow his lead. When your pool is green, you need to raise your chlorine to shock level (that's based on yourCYA-- see the link to the "best guess table in my sig) and hold it there until the algae is all dead. By shocking every two days ( how do you know the chlorine level was high enough?), your chlorine was drifting up and down, and the algae was never completely killed off, let alone filtered out of the water. Once you kill and filter all the algae, then you need to make surre your chlorine levels stay high enough in the pool so the algae doesn't come back. That will be easier to do once you have CYA in the water to protect your chlorine from the sun.

Once you add CYA, it takes up to 4-5 days for it to dissolve, so don't expect it to show up before then. Also, if you backwashed the filter after adding it, it all just washed out and you'll have tostart over.

Just a warning about the tabs--the ones you are using contain copper, which is not a good thing to have in the pool. When people start having green hair and fingernails,andgreen stainingon the liner, copper is the culprit. Normally people blame the chlorine, but it's the copper. I woild strongly advise you to switch to tabs that don't contain copper.

[BethL]

Hi Aylad, I appreciate the response.
Ack! I was on the road all day so haven't gotten to buy bottle test kit yet. However, I shocked yesterday and just went and used on of the (useless-haha) test dipsticks since that was the only measure I have on hand. And the pump has run for the last 24 hours solid. I realize these are estimates based on how well I discern colors:
Total Hardness: 200
FC: 3 (bromine 6)
pH : 7.5
Total Alkalinity: 240 (or more, bluish on stick)
Cyanuric Acid: looks like it fell between the colors for 0 and 30-50 range, so I'd have to guess more than zero but less than 50--at least something's registering on there now.

So, aside from the sky-high alkalinity, it looks pretty good according to the "ideal" ranges given on the HTH strips. BUT, it is even greener than yesterday! Dirtier than when I first started working on it daily, even. A deep, darker than emerald green.

I see in your chlorine chart, I'm close right at this moment. Should I shock it again tonight to keep the chlorine high or would that be too much? Is the algae controller i have useless since it says the pool should be clean before using? (9.96% n-alkyl, .04% n-dialkyl). I'm at the point of just emptying it but our yard holds water really badly, but I don't know what else to do with it.

[Watermom]

Go ahead and shock the pool again. Don't use the algae controller. Also, you don't have a bromine pool. Just ignore that reading.

[aylad]

As Watermom said go ahead and shock the pool again, but you need to get thechlorine up to at least 12-15 ppm in order to do any good. If you can , at least take a water sample to a pool store that uses drops, ot strips, and get them to run a set of tests on your water-- just don't buy all the junk they'll try to sell you. We REALLY need a correct CYA level to help you get the pool cleared up. Also, you might want to consider stocking up on some bleach to do the shocking with, instead of the powder--your calcium is getting high and I thnk the powdered stuff you're using is cal-hypo, which is raising it further.

Janet

[BethL]

Thanks again. I'm ordering the good kit today but in the meantime went to the hardware store and bought the 4way kit they had, figuring maybe it was better than the strips until the good one gets here? The nearest pool store is almost 40 miles and I have to drive right past one Monday so will take some then. I tested after vacuuming but before adding a gallon of liquid chlorine.
The chlorine reading scale on this one only goes up to 3.0 (a light yellow), the color I got was deep primary yellow so my chlorine must be very high?
The pH test came out to 7.6
The "acid demand" test determines how many half-pints of muriatic acid I should add; 3 drops means I should add 1.5 pints of muriatic acid (though it cautions not to add more than one pint per day). I've seen this stuff at the hardware store but don't think I've used it.
Total alkalinity reading 10 drops=100 ppm
Unfortunately,now I see it does not test CYA.

So I got into my green pool and vacuumed it, brushed the walls and ladder and poured in another gallon of liquid chlorine. I did notice that the chlorine I bought today was 10% and I swear the stuff I got at Walmart was only about 6%. At any rate, I'll be interested to see what a "real" test reveals.

[aylad]

How's your water looking now? You can force the OTO chlorine test to read higher levels of chlorine by using the dilution method outlined here http://www.poolsolutions.com/gd/how-...d-testkit.html until the good kit comes in. It's still a ballpark, but much better than the strips. If the water is still green, then you need to get that chlorine level back up to the 12--15 ppm range and hold it there--in a 10K gallon pool, one gallon of 6%bleach will raise your FC by 6 ppm, just as a reference.

Janet