Algae dead but pool water will not clear.

[Little Aussie Battler]

Hi Guys my first post

Over a 2 week period I used 140Ltrs bleach 12.5% to bring my pool from a disgusting swamp to an aqua blue. Now I cannot get the water to clear. I can see the bottom of the pool but it is still cloudy. There is also a white film on the pool walls that transfers to my fingers when I rub it. It is now three weeks since I killed the Algae. PH 7.6 FC 3 TA 80 CYA N/A.

I ran the filter 24/7 and after 2weeks cut back to 6hours per day and I have been backwashing and brushing everyday.

Any suggestions?

Mark
ps Great site.

 

[Guest]

first of all WELCOME, :-D

you should run the filter more to clear it up faster, you can scale back once its clear, they also make a water clarifier that i have used in the past and it works really well, i forget the name because i only had to use it when opening.

 

[duraleigh]

Hi, Mark,

Why no CYA in your pool? Without it, it is almost impossible to retain a chlorine residual for sanitation and may well be allowing the algae to not quite all be killed.

Post back why you have no CYA.....there may be a reason I'm overlooking but I suspect that's your biggest problem.....allowing the chlorine to repeatedly get too low to be effective.

 

[Little Aussie Battler]

Hi, Mark,

Why no CYA in your pool? Without it, it is almost impossible to retain a chlorine residual for sanitation and may well be allowing the algae to not quite all be killed.

Post back why you have no CYA.....there may be a reason I'm overlooking but I suspect that's your biggest problem.....allowing the chlorine to repeatedly get too low to be effective.

Hi Dave
I cannot test for CYA, and the pool shop is closed Sunday.There maybe some CYA but I suspect it would be very low. What should my CYA be? SWCG manual suggests 40-80 and up to 100 in hotter climates.

 

[duraleigh]

Hi, Mark,

I overlooked the fact that you have an SWG...sorry. However, that gives me a new question....How did your water get green and swampy? Was the SWG off? As for level of CYA, do what the manufacturere recommends but you need to get your water tested to find out if you have any CYA at all.

Give us a little more history on your situation....I still suspect low chlorine residual but a little info as to how the pool got swampy will probably help a lot.

 

[Little Aussie Battler]

Hi, Mark,

I overlooked the fact that you have an SWG...sorry. However, that gives me a new question....How did your water get green and swampy? Was the SWG off? As for level of CYA, do what the manufacturere recommends but you need to get your water tested to find out if you have any CYA at all.

Give us a little more history on your situation....I still suspect low chlorine residual but a little info as to how the pool got swampy will probably help a lot.

I switched everything off over winter. A big mistake!!!!

 

[JasonLion]

It is very important to know your CYA level. With a SWG I recommend CYA between 60 and 80. That will extend the life of your SWG cell and still be low enought to keep algae under control.

Another thing to look at is the filter. Perhaps you have killed all the algae but the filter isn't filtering effectively. Have you backwashed the filter in the last two weeks? If not you should do so now.

 

[Little Aussie Battler]

It is very important to know your CYA level. With a SWG I recommend CYA between 60 and 80. That will extend the life of your SWG cell and still be low enought to keep algae under control.

Another thing to look at is the filter. Perhaps you have killed all the algae but the filter isn't filtering effectively. Have you backwashed the filter in the last two weeks? If not you should do so now.

Hi Jason
I backwash daily. After dealing with the swamp a daily backwash is an easy chore. I have been filtering through the pool cleaner as the water level is below the skimmer box. The skimmer box is currently under repair so I guess I don't have the usual volume of water being filtered :idea: I think I need to increase the filters running time. What do you think?

Mark

 

[JasonLion]

Yes, a longer pump/filter run time will help. But I think there must be something beyond that going on.

A sand filter should be able to clear the water in seven to ten days at most as long as nothing is growing in the water. That suggests that either you haven't killed everything or there is some issue with the filter. Have you checked to see if your FC level holds overnight with the SWG off? That is a very reliable test for something growing in the water.

 

[Little Aussie Battler]

Yes, a longer pump/filter run time will help. But I think there must be something beyond that going on.

A sand filter should be able to clear the water in seven to ten days at most as long as nothing is growing in the water. That suggests that either you haven't killed everything or there is some issue with the filter. Have you checked to see if your FC level holds overnight with the SWG off? That is a very reliable test for something growing in the water.

Hi Jason
Pool Shop water analysis TC.5 FC 0 PH 7.8 TA 150 CYA 0 SALT 4570

 

[The Mermaid Queen]

Not Jason, but I can see two major things, and a minor one.
First thing is chlorine. Get some in there either with your SWG or preferably some bleach. If you have some dichlor or trichlor lying around, you can use that, because...

the second thing is your CYA. Especially with an SWG you need to get that up to what is recommend in the instructions for your SWG. Usually around 80.

The minor thing is your pH. If you get that down to 7.2-ish, your chlorine will work better.

Ok, now for Jason's answer...

 

[JasonLion]

The crucial issue is the CYA. With CYA of zero there is no way the SWG can keep up with loss from sunlight, so FC is going to go to zero every day. That means there is sure to be something growing in the water and no way for the filter to keep up even if it is working perfectly.

You need to get your CYA level up ino the 60-80 range. Once you do that it will be possible to kill off all the algae once and for all.

 

[Little Aussie Battler]

So first I get my CYA up then I shock with bleach again?
Thankyou Guys

 

[AnnaK]

I just recently cleared up my jade green swamp by keeping the chlorine level at somewhere between 28 and 35 ppm. I can't be more specific because I didn't have a proper test kit at the time. I ran the pump 24/7 for five days straight. The colour went from deep green to turquoise to blue within four days. It stayed blue but there was a definite cloudy haze - the dead algae.

Today is actually Day 10 and the water's appearance is back to normal with a nice clean sparkle to it. Now I'm letting the chlorine level drop and am running the pump on its night time cycle again.

It takes a while to clean up really green water. Killing the algae is easy. Getting their remains out is what takes time and patience.

Anna

 

[The Mermaid Queen]

So first I get my CYA up then I shock with bleach again?
Thankyou Guys

You can do these simultaneously. CYA takes up to a week to dissolve, and if you leave the pool with 0 FC you will be fighting a swamp again. Use Jason's calculator (in my signature) to help you figure out how much CYA and bleach you will need. Add less than the recommended amount of CYA. Put it in a sock and hang it in front of a return, if possible. Or a sock in the skimmer. Retest in a week, and add more if needed.

Meanwhile, keep your FC up by adding bleach daily.

 

[Little Aussie Battler]

[quote="Little Aussie Battler":ynb67wi8]So first I get my CYA up then I shock with bleach again?
Thankyou Guys

You can do these simultaneously. CYA takes up to a week to dissolve, and if you leave the pool with 0 FC you will be fighting a swamp again. Use Jason's calculator (in my signature) to help you figure out how much CYA and bleach you will need. Add less than the recommended amount of CYA. Put it in a sock and hang it in front of a return, if possible. Or a sock in the skimmer. Retest in a week, and add more if needed.

Meanwhile, keep your FC up by adding bleach daily.[/quote:ynb67wi8]
Thanks Guys
I have gone to FC 12 with no addition of CYA. I have found that putting higher numbers of CYA into the pool calculator requires higher FC levels. Am I correct in doing this?

 

[The Mermaid Queen]

[
Thanks Guys
I have gone to FC 12 with no addition of CYA. I have found that putting higher numbers of CYA into the pool calculator requires higher FC levels. Am I correct in doing this?

Yes, the higher the CYA, the higher the FC you need to be effective. While the CYA keeps the FC in the pool, and not burned off by the sun, it also hinders the effectiveness of the FC, so that you need more FC to be effective.

You need to check your SWG manual for the amount of CYA it recommends, get that amount in your pool, and keep your FC at the proper level using the pool calculator.

For now you probably still need to be shocking with bleach, unless your water has cleared...

Is your water clearing? Are you keeping your FC at about 10 to ensure the buggers are dead? Is this the start of your swimming season?

so many questions, so little time!!

 

[Little Aussie Battler]

[


Yes, the higher the CYA, the higher the FC you need to be effective. While the CYA keeps the FC in the pool, and not burned off by the sun, it also hinders the effectiveness of the FC, so that you need more FC to be effective.

You need to check your SWG manual for the amount of CYA it recommends, get that amount in your pool, and keep your FC at the proper level using the pool calculator.

For now you probably still need to be shocking with bleach, unless your water has cleared...

Is your water clearing? Are you keeping your FC at about 10 to ensure the buggers are dead? Is this the start of your swimming season?

so many questions, so little time!!

Do I run the SWG as per normal while I am shocking with bleach?



The water looks clearer than it was yesterday but I will keep the FC up around 10 Is this our swimming season? Well we had 35 degrees yesterday and there were a couple of human bodies splashing around in the pool. I hope you are not jealous Mermaid?


Mark
ps thanks for the info

 

[The Mermaid Queen]

Regarding running your SWG, I really do not know. I do not think it would hurt it.
not too jealous, just trying to get a handle on this 'other side of the world' thing!
If I convert correctly, your pool is like a bathtub!! (95F) or a hot tub!

 

[Little Aussie Battler]

Regarding running your SWG, I really do not know. I do not think it would hurt it.
not too jealous, just trying to get a handle on this 'other side of the world' thing!
If I convert correctly, your pool is like a bathtub!! (95F) or a hot tub!

It was a tad warm but that was the air temp. Today we are around (20C) and 19C in the pool. Mid 20's is
normal for this time of year. It starts getting warmer from now on. Late Dec through Jan and Feb are
normally the hottest months:- high 20's to mid 30's. I agree this global community thing is hard to get
your head around but it's all a bit of fun. :-D

The pool is definitely looking clearer today. I better go and dose it up.
cheers