Small amount of Algae and slightly cloudy - Plan of Attack

[Tallcane]

Hey everyone,

I am having some recent trouble with my pool and want to verify I have the right approach to resolving any issues.

I am in North Florida and have a 36,000 gallon SWG pool. About ten days ago I happened to be home when the "pool guy" was there. I asked him what his recent chlorine readings have been and he admitted to me he had not been testing (he thought he could rely upon the green lights on the salt cell). He took a reading that day and came back with zero FC. I had the salt cell set at a relatively low setting and it clearly was not keeping up. I immediately dropped a floater in with some trichlor tabs. He must have come back the very next day and poured some chlorine in because the next afternoon I did a test and got a FC reading of 10+.

Well, this past weekend I noticed some little black dots on the bottom of the pool in some areas that have some pitting (I need to refinish the pool). I swam down and discovered they were small "piles" of dark green algae. I took a brush to all of the spots I could see and they came up relatively well, usually just leaving a faint green residue. Also, the pool is showing slight cloudiness.

The pool guy was back yesterday and I asked him to again tell me his numbers and he told me get got a FC of 10, PH of 7.4 and a CYA of 0. His CYA number seems off to me since the pool has managed to hold that 10ppm FC reading for about a week.

I jumped back on this site yesterday and realize that I need to shock my pool to kill off any organic material in the pool. In preperation for doing so, I pulled out my trouble free test kit and ran my own test. My numbers are as follows:

FC - 10.5
CC - 0
PH - 7.5
CYA - 40
TA - 140
CH - I had trouble getting any reading on this.

In an attempt to verify my number I went to the local pool store and here are their numbers:

FC - 5
CC - no result provided
PH - 7.8
CYA - 50
TA - 185
CH - 240

They verbally told me that my phosphate readings were "very high" and then asked what kind of filter I had. I responded that I had a cartridge filter and he made a face like I was in trouble. I then told him that I was under the impression that the first thing I needed to worry about was shocking the pool to kill off any organics and then would worry about everything else (I should add that I have had this pool for ten years and never (a) had algae issues or (b) had phosphate issues.) His response befuddled me. He told me I did not need to worry about shocking the pool, that I had enough FC and all I needed to do was to get the phosphate issues under control. They advocated 18 ounces of something called "pool perfect + Phophate remover".

Even thought I only found a little bit of algae, this seems like a big warning that I should jump on. I think shocking is still justified and wont hurt anything.

My plan is to run a second test today to confirm my numbers. If I confirm them I intend to go forward with shocking the pool at shock levels indicated using the pool calculator (at current CYA readings I will be around 15 PPM). Once I complete the shock process I will raise my CYA and account for any calcium harness issues I have. A couple of questions:

1 Any issues with my approach?
2. Do I need to turn off my SWG while shocking the pool?
3. Once done, do I need to worry about phosphate levels?
4. Anyting else I am missing?


Thanks for everyones help.

 

[duraleigh]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

1 Any issues with my approach? Not now. But trusting someone else with your testing ineveitably leads to problems. Trust your own testing!
2. Do I need to turn off my SWG while shocking the pool? I suggest yes. It is easier to manage your FC throught the process....especially at the end
3. Once done, do I need to worry about phosphate levels? Bogus Bogus Bogus
4. Anyting else I am missing? read "How to Shock Your Pool" up in Pool School and follow that article to a T

PS - Stay out of that Pool Store....He/She is ignorant or untruthful.

 

[Articfox918]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

1 Any issues with my approach? Not now. But trusting someone else with your testing ineveitably leads to problems. Trust your own testing!
2. Do I need to turn off my SWG while shocking the pool? I suggest yes. It is easier to manage your FC throught the process....especially at the end
3. Once done, do I need to worry about phosphate levels? Bogus Bogus Bogus
4. Anyting else I am missing? read "How to Shock Your Pool" up in Pool School and follow that article to a T

PS - Stay out of that Pool Store....He/She is ignorant or untruthful.

Beat me to it by seconds.....my exact thoughts. follow these suggestions = no problems

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Thanks Duraleigh.

How long are your test kits good for? I think the last one I purchased from you may be close to a year old. I have kept it in my air conditioned home. I want to make sure the test materials I am using are still valid.

CYA testing is a pain and I have a hard time trusting myself with those results.

 

[Articfox918]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

CYA testing is a pain and I have a hard time trusting myself with those results.

If you are having trouble reading CYA test you can pour water from view tube back into bottle and redo it several times and get an average result. I did this at first until I got the hang of it. The key is to slowly pour and stop just as the black dot disappears.

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Update. Tested twice today and FC was at 10 both times. Cya was consistently between 30 and 40. Finally added liquid chlorine to raise FC to 16 to start shock process.

Interestingly, I spoke with pool guy today who was really taken aback by my intended course of action. He felt that my intended course of action was against what his "Florida license training" taught him and was not a recommended course. He specifically said that there was no reason to raise the chlorine that high because once it reached a threshold level it did not need to go higher to kill organic material.

He was very polite but has made it clear that he thinks I am totally off. Why is he so surprised by this?

Side question. Am I correct that I should not allow swimming while chlorine levels are so high?

 

[jblizzle]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

He was very polite but has made it clear that he thinks I am totally off. Why is he so surprised by this?

Side question. Am I correct that I should not allow swimming while chlorine levels are so high?

Probably because he was not taught the relationship between CYA and FC.

Only safe to swim when FC is below shock level (and above the minimum FC level, and CC not more than 0.5, and water is clear).

 

[Smykowski]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Update. Tested twice today and FC was at 10 both times. Cya was consistently between 30 and 40. Finally added liquid chlorine to raise FC to 16 to start shock process.

Interestingly, I spoke with pool guy today who was really taken aback by my intended course of action. He felt that my intended course of action was against what his "Florida license training" taught him and was not a recommended course. He specifically said that there was no reason to raise the chlorine that high because once it reached a threshold level it did not need to go higher to kill organic material. The moment you put chlorine of any type in a pool that has living algae in it, that chlorine immediately starts to get consumed, which drops the level. This is why you need to keep adding chlorine to maintain a shock level over an extended period of time to wipe out ALL of the algae

He was very polite but has made it clear that he thinks I am totally off. Why is he so surprised by this? There seems to be a general lack of understanding about both the CYA/Chlorine relationship and how chlorine does its job by both the general public and professionals as well.

Side question. Am I correct that I should not allow swimming while chlorine levels are so high?If your FC level is above shock level given your CYA, you are correct, don't swim. It is safe to swim up to shock level but not above.

Blizzle beat me to it, but I'll post anyway.

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Is there any reason at all for chlorine levels to drop during nightime other than being consumed by algae? I ask becuase the proverbial pool guy seemed to think there was. He acted like I should expect it to fall no matter what.

I am running the pump all night. Would that make a difference?

I saw about a 5ppm drop in FC overnight so I clearly have something eating up the chlorine. Is there any typical time period for how long shocking takes? My pool was not green or anything. I had simply found some small spots or "blobs" of algae on the bottom of the pool and had some haziness.

 

[Bama Rambler]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

There will be no FC loss at night unless something is consuming it and if it is then you need to perform the shock process. Thousands of us have ran the OCLT without any loss overnight so your pool guy is wrong if he believes you normally lose FC at night.

Running your pump wil not make any difference. A lot of people run there pumps 24/7 and don't have a loss overnight.

5 ppm loss overnight is a lot and if it was tested after the sun went down and before it came up. You definitely need to shock. The fact that you saw "blobs" of algae verifies that fact!

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Update: second night during shocking and I saw a 2ppm loss of FC. Definitely better but not there yet.

 

[duraleigh]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

Is there any reason at all for chlorine levels to drop during nightime other than being consumed by algae? I ask becuase the proverbial pool guy seemed to think there was.

Two things consume chlorine...sunlight and organics in your pool...period.

If you have no sunlight and no organics in your pool, there will be no chlorine loss. (that's not perfectly, totally, absolutely true, but it is for pool discussions)

You still seem to want to get the pool store or the pool guy involved in your process when they clearly don't agree with what you are doing. You end up in the middle....confused and often making bad, compromising decisions.

You should choose one set of advice or the other but blending two opposing ideas will result in trouble for you and your pool.

(Didn't see your other post 'til now but your kit should be fine since you have stored it indoors)

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

After spending a lot more time reading in here, I believe that I have black algae. The good news is that I have been brushing all the spots I can find with a wire brush. Man, this stuff is hard to get off. I dont have much of it but when you find it, it is tough to break that outer layer.

I have been holding the FC at shock levels for a few days now. I understand that a black algae battle is a long term battle involving lots of scrubbing. Do I have to hold my pool at shock level the entire time or can I return the water to swimmable (but high) levels of chlorine?

When this started, I was hoping for a quick fix of shocking the pool and moving on. It does not seem like black algae is a quck fix type of algae. Taking the pool off line for an extended period of time is a huge inconvience this time of year as I have three young kids who spend their summer in the pool. Our sanity is at stake...

If at all possible, I would really like to find a way to treat this while using the pool. Is that possible?

 

[duraleigh]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

return the water to swimmable (but high) levels of chlorine?

That'll work just fine. I would suggest maybe 30% or so over normal max suggested. That way it is plenty safe to swim and will help you get rid of the algae. Steady, vigorous brushing will be your friend.

 

[Tallcane]

Re: Small amount of Algae and slightly cloudy - Plan of Atta

return the water to swimmable (but high) levels of chlorine?

That'll work just fine. I would suggest maybe 30% or so over normal max suggested. That way it is plenty safe to swim and will help you get rid of the algae. Steady, vigorous brushing will be your friend.

Thanks.

I am going to start raising my CYA to 70 (I have a swg). Once there I will maintain a FC level around 5 ppm. Does that make sense?