Conflicting Advice and a slightly cloudy pool

We bought a new (to us) house this spring that came with a pool, it is about 70,000 litres (18,500 gallons), vinyl liner, sand filter, gas heater, and so far things have gone relatively well. We did have a pretty good algae bloom in July while we were away on vacation, but following a lot of good advice in this forum on similar issues I was able to get clear water back in under a week.

I test almost daily using strips and about twice a week with a drop tester (not the preferred taylor as I have not been able to find it in Canada and i am not sure i can have liquid chemicals shipped over the border). I use Pucks in a chlorine feeder, and shock with liquid chlorine (11%)

Now I have slightly cloudy water that I cant seem to clear. I can see the bottom of the deep end, the water just isn't perfectly clear like it used to be.

So, off i go to the usual pool store with a water sample, and their printer is broken, so he just tells me my chlorine is a little high (which I knew because I turned the chlorine feeder up for a couple of days when i went away for the weekend to avoid another algae bloom - it is back to normal now), and everything else is pretty good "don't bother doing anything about it this late in the season and you will close the pool in a few weeks anyways" he says. He has no advice for the cloudiness, so I leave without buying anything.

We use the pool for 2 days and the cloudiness doesn't change, so fearing that it may be algea waiting to bloom, I added about 2.5 litres of 11% chlorine when we were done swimming on Saturday.

Yesterday, there is still no change so i go to a different pool store with a water sample, and here is what they told me;

FC = 9
CC = 9 (i called them back and they meant tc)
PH = 7.6
Alk = 90
CYA = 70
CH = 250

They tell me my stabilizer is high and the chlorine is high, so turn off the feeder and wait for the chlorine to fall to around a 2 - they are afraid i have chlorine lock. they think the cloudiness may be caused by too much stabilizer and chlorine. Wait for the chlorine to fall and if it doesnt clear then we can use a clarifier - i left the second pool store without buying anything

Based on what I have read on here, I know my stabilizer is high, but given the stabilizer of 70, a chlorine of 9 is within the target range - Is this correct? I fear 2 is too low for a CYA of 70

I have turned the chlorine feeder off so I do not increase CYA any further and will just use bleach (liquid chlorine) for the balance of the season.

I still fear this cloudiness is algae waiting to bloom, should I follow their advice and wait for the chlorine to fall, or should I ignore their advice and shock?

Thanks for your help, and sorry for the long post, i am trying to give as much info as possible.

Mike

With cya of 90, you need to be shocking your pool up to 20 and try to maintain that level until the pool clears and you can go from sundown to sunup without losing more than 1ppm of chlorine. Test as often per day as you can (at the very minimum 2x per day although more often is better) and each time take it back up to 20. Also run the pump 24/7 while clearing the pool and backwash when the pressure increases 8-10psi over your clean filter pressure.

When you get it all clear, you can let the cl drift down but keep it between 5-10 ppm all the time to avoid another algae bloom. No more tabs in the feeder as they will continue to add more cya.

Hope this helps and, welcome to the forum.

Measurements from test strips and from pool stores, especially for the CYA reading, are notoriously inaccurate. I strongly suggest you get yourself a Taylor K-2006 test kit which you can get from Amazon here which will support this site or you can get it cheaply here that might take longer to ship.

Chemgeek,

Can he get it shipped to Canada from either of these sources?

Janet

Whoops! No he can't. From Canada, it's much more expensive due to the exclusive distributor/importer Lowry & Associates. In Canada, he can get the kit from Apollo Pools (Piscines Apollo).

I actually just found Lowry just before I saw this post and gave them a call. they have given me a couple options to get a kit by the end of the week. It is much more expensive in Canada, he explained it was mainly because they had to add a complete set of French instructions and labels as well as some safety information regarding the chemicals.

I have to completely agree that the CYA test from the pool store is not accurate, I got my water re-tested yesterday and they told me I was a 50 - that is a drop of 20 in 24 hrs, which I believe to be impossible (from reading posts here). I am beginning to think the 70 was a mis-read, as all previous tests all summer have been below 50, and since the last reading below the 70 I had only put 2 pucks through the pool.

my new readings were;

FC = 5 (a drop of 4 in 24 hrs)
TC - I had someone different and she would not give me this today - told me it didn't matter
PH = 7.6
Alk = 90
CYA = 50
CH = 250

I told them that the water was cloudier since I turned off the feeder, so I though I should start adding chlorine because I dropped 4 points over night. They started telling me they were worried about chlorine lock, and I told them I was worried about the algae growing on the side

Long story short, I bought more 11% chlorine (just in case), and by the time i got home there was a response from Watermom confirming my approach, so I shocked to 20 and turned the filter on recirculate and brushed the whole thing.

I re-tested this morning the best I could using distilled water and figured 16-18 so I added enough chlorine to raise by 4 (in case it was 16).

I will test, adjust and brush when I get home, but the water was already looking much better this morning.

Thanks for the advice so far, i will keep you updated

You're doing a great job so far, stay the course and you'll get it cleared up. The only thing I would do differently is to put the filter back in filter mode, not recirculate--the bleach is killing whatever organic "stuff" is in the water, but it's the filter that will remove it. If you remove the filter from the process, you'll have clean but still cloudy water.

Janet

Last night i turned the pump off for about an hour and a half and waited for all the dead algae to settle and then vacuumed the areas where the most had settled on waste. I then added more bleach and turned the filter back on.

This morning I put the auto vacuum back in the pool and added 5 litres of bleach. Things are looking pretty good.

Here is where I am totally confused - I still don't have my taylor kit yet, so I went to the original pool store to get more chlorine and thought i would have my water tested.

They have the computer based light tester there, and here is what they told me

FC = 5.7
TC = 5.7
PH = 7.4
CAL = 110
Alk = 77
CYA = 10

According to this the fight is over, correct? it looks safe enough to swim - and the pool looks pretty good.

But my questions are now;

How can my chlorine be 5.7 if I added 5 litres of bleach this morning? - the pool calculator says that much bleach raised fc by 4.4

How can I possibly go from a cya of 70 3 days ago, to a 50 2 days ago to 10 today (the 70 and 50 were using the visibility test, the 10 was from the computer)

Which test is more accurate - who should I trust?

Lastly - should I turn my chlorine feeder back on, should I leave it off, should I shock again to be sure?

A couple of my friends say I should just make the switch to salt

Thanks again.

Pool stores are notorious for giving you inaccurate readings even with some so-called fancy computer testing. Hopefully your kit will come soon so you can test your water yourself. If the pool is still cloudy, I'd go ahead and keep the cl high for another day and run the pump 24/7 to filter out the dead algae. I wouldn't use any more tabs in the chlorine feeder until you can verify what your cya reading is when you get your kit. When the kit comes (hopefully tomorrow!) post some readings for us to look at.