Chlorine Questions

[danaz]

Hi all,

Currently clearing up green algae problem in 25k gallon pool with TF-100 kit for testing.

TA 110
CH 200
FC 1
CC 1
TC 5
CYA 110
PH 7.4

Those were my numbers. Drained over half of the water over the weekend and got the CYA down to 40 and just started shocking the pool. Poured 4 gallons of 10% chlorine in and scrubbed it for a couple of hours then when i tested the FC was just 2.

Is it normal for the FC level to be so low after starting to shock? I know the chlorine is killing the algae but it seems a long way from the target of 16 FC.

So i poured another 3+ gallons of chlorine in and will test again in a few hours.

One other question about the chlorine test. I have the TF-100 kit and on the chlorine test it says something like 'heaped spoon of powder and mix then drop the R00XX fluid in until the solution turns from pink to clear'. Now, does 'clear' mean transparent or does it mean 'white' - because mine turns from pink to milky white.

Thanks

Draining the swamp!

Hazy color 1hr into shocking

 

[JasonLion]

99% of the time, clear means clear. However, what really matters is when the pink goes away. If the sample turns milky and there is no sign of pink then you are done.

 

[danaz]

Well...this whole process is beginning to look like a waste of time. Just tested again, and the FC level is still 2.

So that's almost 10 gallons of chlorine in less than 6hrs, and the chlorine level has not moved a bit. That's pretty much identical to what happened when the CYA level was over 110, so I don't know what has been achieved by draining 60% of the water out if the chlorine level is still not moving.

According to the pool school article, I am supposed to maintain a shock level of 16 and i can't even get above 2!

The chlorine test seems like it is just not working. The solution turns slightly pink, and after approx 10 different tests in 10 different situations over the past couple of months it always gives me a result of 2/3ppm no matter what. It just turns milky white after 5 drops.

I can't believe that 10 gallons of chlorine would not produce a different result. I just don't know how much time and money to keep throwing at this.

 

[jblizzle]

Sounds pretty normal for starting with a very green pool.

The FC is killing algae ... having the lower CYA means you will not have to hold as high a FC level when it eventually starts to hold. The FC would be dropping just as fast at the high CYA.

That said, I have never seen the milky white water in the FC test, so maybe something is wrong. You could try testing a diluted bottle of bleach directly and see what level you get ... although I am not sure how much to dilute it for the test.

 

[danaz]

Well i questioned the accuracy of the chlorine test since the instructions say to add the reagent until it turns 'clear' but it has never turned clear with my kit. It just is slightly pink, then it goes white, but never close to being clear or transparent in any way.

 

[Isaac-1]

I just have a minute before I have to go so will leave the testing procedure to someone else. It is normal to go through a lot of chlorine when staring to clear a swamp, it may be reacting with ammonia in the water and canceling each other out very rapidly, or may be killing algae, either way the answer is more chlorine. AS you get closer to clearing the FC will hold longer and longer.

Ike

 

[bsimo57]

Just an example of how much bleach you will go thru. I am helping a freind who has a 36k gal inground pool who's water was not to bad, very cloudy but no green. It had no cya, fc was 2 and cc was 2. Since Sunday we have used 24 142oz 6% jugs and 16 128oz 12.5% jugs. We're almost there, we could see the drain at the 8 ft end this afternoon, cc was 0 and we are going to hold the fc @ 12+ until we pass the oclt.

 

[Richard320]

It's probably normal. Check out this thread, scroll down until you see the picture of the empties.

 

[danaz]

Thanks for all the replies and advice, especially the news that clearing up a swamp takes a LOT of chlorine.

Glad to report last night and today has worked out better.

First thing this morning I went to home depot and got 20 gallons of 10% chlorine. FC was 2 so dumped 5 gallons in and at 2pm the FC was holding at 22! For the first time the chlorine test was a vibrant pink color - a miracle!!! Topped it back up to shock level and then couple hours later it was back down to 22 so topped it up again. Left it two more hours and FC is holding at 26 with CC of zero.

So now i'm planning to do the overnight test tonight and if all is good then what?

Do i just let the chlorine level drop to the target rate and then get the PH right and maintain?

How long is that likely to take with 100deg AZ sun shining down on it all day?

The pool is kinda hazy (see pic below) so have just been scrubbing it every couple of hours but it is slowly clearing up. There is not a single spec of green anywhere now, and when i run the brush over it i barely see a whisp of dead, milky algea anywhere. The hayward vacuum has been running for about 48hrs straight now and seems to be doing a good job.

What should i expect now? Will the water become crystal clear on its own over the next few days? I am real reluctant to add anything else after having to drain over 50% of the old water just to get rid of all the junk chemicals.

Pool couple of minutes ago with FC 26 and CC 0

This is a thing of beauty!!!!

 

[jblizzle]

Nice!!!.

Re-read the article on shocking ... you have to pass all 3 tests to stop shocking. Cloudy water is not good.

Really no point in doing the OCLT until your water is clearer, although it could make you feel better if you pass knowing that everything must be dead.

It is highly unlikely that you cleared a green pool in 2 days and can pass all 3 tests.

 

[Leebo]

Maybe it's just my "routine".....but I don't think you're supposed to put the spoon in there. Keep it dry and clean all the time.

 

[danaz]

Maybe it's just my "routine".....but I don't think you're supposed to put the spoon in there. Keep it dry and clean all the time.

I found it awkward to mix so i generally keep the spoon in there, hold something over the top, and shake it up so the spoon rattles about and disrupts the powder crystals.

 

[jblizzle]

Get the Speed Stir

You should try to keep that spoon clean and dry ... although it should dry by the next time you need it.

 

[danaz]

Nice!!!.

Re-read the article on shocking ... you have to pass all 3 tests to stop shocking. Cloudy water is not good.

Really no point in doing the OCLT until your water is clearer, although it could make you feel better if you pass knowing that everything must be dead.

It is highly unlikely that you cleared a green pool in 2 days and can pass all 3 tests.

Good point, thanks. I suppose I have to keep it at shock level until it turns clear. I'm just thankful that the battle seems to have turned in my favor today. The war clearly ain't over though.

 

[danaz]

It's probably normal. Check out this thread, scroll down until you see the picture of the empties.

That thread makes my experience seem like a stroll in the park. Thanks

 

[danaz]

Update for today which is now Day 4

At 10pm last night FC 18 so added 1.5 gallons to get back over shock target
8.30am today FC 18 again, CC was 0.5, so added another 1.5 gallons to get back

After reading all the posts about how much chlorine this process uses up, i am trying not to be stingy with the gallons. It seems best to hit it hard and hit it often so i've made my target 24 instead of the '20' recommended by the CYA/chlorine chart.

Pool is looking clearer day by day, and starting to get a bit of the blue color back into it. Should be working but thought i'd make a little comparison. Kinda shocking to see the change in color side by side like this. But now i really have to work.

 

[danaz]

Another day 4 update. It's 1.40pm (over 5hrs since last added chlorine) and FC is 26, CC is 0

Pool looking very clear and blue now. Crappy camera pics not doing it justice, but the drain in the 10ft deep end looks like you can reach in and touch it.

 

[Richard320]

Excellent!!

And thanks for the pictures. I'm gonna bookmark this thread - the side-by-side progression is great!

 

[danaz]

Will be trying the overnight test tonight.

Just noticed something in the pool though. Looks like a couple of tiny 1-2" scratches where the wall of the pool meets the floor. Obviously i can't get in to investigate right now, but resting my shades on the surface i got a good look and they just look like little brown/black scratch lines. From the location, and the way they all run perpendicular to the wall along the pool floor, it looks consistent with scratches from the brush as it makes the 90deg tilt onto the floor of the pool.

Then I took a look at the brush and it does look like the corners of the head have become a bit rounded.

What should i do about this?

I don't even know how long these have been present since the pool has been green for a month or so.

Is it a real concern or just an aesthetic problem. Would a bit of leslies patch-it solve the problem, or should i be able to wet-sand the scratch off. Right now I don't know if the black/brown scratch has been added on to the plaster, or if it has scraped off a layer of plaster finish.

 

[Bama Rambler]

The "scratches" are most likely just deposits left on the plaster. You'll probably be able to rub them out.