Getting Fustrated....

[marianegs]

This is my first year with a pool, and I started with the TFP method, and have done nothing else. Beginning of the summer through half way through July, its been easy, my test have been good, no problems at all. Water was crystal clear, everything was great. Then I got algae, don't know how I got it b/c I am pretty on top of it, but who knows, I slammed it, (it was an easy slam) was done in 2 days, and water was beautiful again.

Now I have algae again and I don't know how I am getting it. I consistently keep the chlorine higher that I am supposed to, (Supposed to be max 5 and I keep it a max at 6). It does not gets down to below 4. Anyway long story short, I have algae again.. I am in the process of slamming it again.

Last week I was away for 4 days and I brought the water up to shock level and added two pucks. When I came back, my Chlorine was at 10, so it didn't go below that. SO my question is..

Can it be I don't run my pump long enough. I run it 5 hours a day (in the evening from 5-10 pm) I do that because that is when I add the bleach. SO if I am not running the pump long enough can that be the issue? OR the return is right where the ladder is and the return goes in between the two ladder treads, can that be it? I am just at a lost... Ughh... Thanks for listening this far! Here are my numbers right before I began my slam:

Fc:6
Cc:0
Ph: 7.5
Ta: 100
Ch: 275
Cya: 35-40

 

[DaninFLA]

When you are finishing your SLAM, what is the result of your OCLT? have you removed your ladder to make sure there is no algae under the rails etc?

pump run time does not have an effect on algae growth, the key is your FC levels. you run your pump in the evening/night I see. I guess its possible you could get areas of very low FC near the surface that could allow algae to start growing? can you modify your run time to run during the day? if you add bleach at say 6pm, then have the run time from 1:30p to 6:30p. a half hour is plenty to run the pump after adding bleach.

I suspect you have a source of algae that you are not eliminating 100% when you do the SLAM. it could be a small amount, the key is the OCLT and what your starting FC levels are when you do that. do another SLAM and report the findings at the end for the OCLT, which should be done at shock levels. remove your ladder from the pool when you shock and give it a good scrubbing/inspection and leave it out until the SLAM is over.

 

[cowboycasey]

I would bet you are getting algae in the ladder or somewhere, somehow... once it starts as you know it can get out of hand in a hurry.. wherever it is starting from the chlorine is below recommended levels...

You could try to find the low spot by using the OTO comparator and taking samples of water from around your ladder or anywhere you suspect the chlorine may be low..

 

[DaninFLA]

also maria, the CYA/FC chart is based on having no algae present. the FC levels are designed to keep algae from starting, the FC amount of chlorine in the chart is to oxidize algae trying to form. the problem with algae is it multiplies exponentially...I.e. 1 become 2, 2 becomes 4, 4 becomes 8, etc and it can multiply very quickly.

as an example, with your FC amount set to within range for your CYA for a pool properly SLAM'd - your pool is constantly being bombarded by algae spores from the environment. the FC levels are able to kill off those low numbers of algae spores.

but on the flip side, if you leave some algae in your pool from a SLAM, you already have thousands and thousands of spores in the pool. the FC amount is enough to slowly hold them with minimal growth, however they are still gaining, and once they hit the tipping point...boom...full blown algae explosion like you are seeing. the FC amounts are just not enough to overcome the exponential growth at a certain point and the growth rate explodes.

that's why its critical that you start with zero and then your FC will prevent new algae from forming. if you already have algae in your pool, raising your FC to the recommended levels will NOT overcome the algae growth and kill them...that's where the FC SLAM levels come from. that's the amount to overcome the growth rate and then start killing them off.

hope that makes sense.

 

[borjis]

2 day slam? that sounds unusually short.

 

[pabeader]

Would be the shortest one I've read about.

 

[otter86753]

I have completed a two day SLAM and could have completed a one day SLAM, but extended another night to make sure. I watch my pool like a hawk!

 

[pabeader]

Wow. Must have been almost there to start with. Or else did the test every hour thing. No way to go from Green to Clean in that time I would think.

 

[otter86753]

I never said it was green; it was just cloudy!

 

[pabeader]

Ah, that's make more sense. I get so used to fighting the green meany I forget about just cloudy. So, "almost there" was the correct comment. Got it!!

 

[DaninFLA]

correct, when my cell went bad and I didn't catch it for a couple of days, my FC went to zero and the pool looked cloudy. I bumped FC to shock level, lost about 10ppm overnight and re-added the next morning and then passed the OCLT that night. when you get it early it can sometimes just be a day or two of elevated FC to get you back

 

[singingpond]

This is my first year with a pool, and I started with the TFP method, and have done nothing else. Beginning of the summer through half way through July, its been easy, my test have been good, no problems at all. Water was crystal clear, everything was great. Then I got algae, don't know how I got it b/c I am pretty on top of it, but who knows, I slammed it, (it was an easy slam) was done in 2 days, and water was beautiful again.

Now I have algae again and I don't know how I am getting it. I consistently keep the chlorine higher that I am supposed to, (Supposed to be max 5 and I keep it a max at 6). It does not gets down to below 4. Anyway long story short, I have algae again.. I am in the process of slamming it again.

Last week I was away for 4 days and I brought the water up to shock level and added two pucks. When I came back, my Chlorine was at 10, so it didn't go below that. SO my question is..

Can it be I don't run my pump long enough. I run it 5 hours a day (in the evening from 5-10 pm) I do that because that is when I add the bleach. SO if I am not running the pump long enough can that be the issue? OR the return is right where the ladder is and the return goes in between the two ladder treads, can that be it? I am just at a lost... Ughh... Thanks for listening this far! Here are my numbers right before I began my slam:

Fc:6
Cc:0
Ph: 7.5
Ta: 100
Ch: 275
Cya: 35-40

Are you brushing regularly during SLAM? Given the size of your pool, I assume you probably have the fairly anemic pump and marginal circulation that such pools come with (intake and return just a few feet apart on the wall of the pool). In this situation it is even more important to brush thoroughly.

I had to SLAM twice last year... Actually, I think the first SLAM wasn't really quite done, and algae returned fairly soon. The second time I did regular brushing, and the algae did not come back afterwards.

 

[marianegs]

This is what is confusing me, my pool is still clear, but you can see on the bottom of the pool streaks of green. They come in long lines of green, and you can see it in the clear water... I thought it might be pollen, but the Overnight test confirmed it, but it went down 1.5 over night, so I know it says if its more than 1 you have algae..

 

[singingpond]

What happens to the green stuff when you brush? See my previous post about importance of brushing during SLAM. Also, you may have already mentioned it, but are you running the pump 24/7?

 

[chem geek]

If you have a blue liner then the green that you see could be yellow/mustard algae which against a blue background looks green. Is the algae mostly on the shadier side of the pool? Does it poof up dust-like when you try to move it? If you have yellow/mustard algae then you have to completely eradicate it and not have it reintroduced because the regular FC/CYA levels are only sufficient for preventing green and black algae, not yellow/mustard (a 15% FC/CYA ratio is needed to prevent yellow/mustard algae at high nutrient levels).

It's also possible you have regular green algae but have terrible bottom circulation in the pool. Remember that sunlight depletes chlorine during the day throughout the pool since UV penetrates deeply through water, so if your circulation is poor you can have no chlorine at the bottom of your pool and allow algae to grow. If you have only one return, see if you can point it diagonally downwards to create more of a swirling motion in the pool and try and get chlorine more to the bottom of the pool.

If you are unable to either eradicate the algae (especially if it's yellow/mustard) or improve the circulation in the pool, then you can use last-resort methods to prevent algae growth that do not break down in sunlight and are not dependent on good circulation.

 

[marianegs]

If you have a blue liner then the green that you see could be yellow/mustard algae which against a blue background looks green. Is the algae mostly on the shadier side of the pool? Does it poof up dust-like when you try to move it? If you have yellow/mustard algae then you have to completely eradicate it and not have it reintroduced because the regular FC/CYA levels are only sufficient for preventing green and black algae, not yellow/mustard (a 15% FC/CYA ratio is needed to prevent yellow/mustard algae at high nutrient levels).

It's also possible you have regular green algae but have terrible bottom circulation in the pool. Remember that sunlight depletes chlorine during the day throughout the pool since UV penetrates deeply through water, so if your circulation is poor you can have no chlorine at the bottom of your pool and allow algae to grow. If you have only one return, see if you can point it diagonally downwards to create more of a swirling motion in the pool and try and get chlorine more to the bottom of the pool.

If you are unable to either eradicate the algae (especially if it's yellow/mustard) or improve the circulation in the pool, then you can use last-resort methods to prevent algae growth that do not break down in sunlight and are not dependent on good circulation.

Maybe its mustard algae then.. Yes I have kept my pump on 24/7, we have been brushing, vacuuming & cleaning the cartridge ever day. It does poof up, when you brush it and the pool will get a little cloudy for about 10 min, then it will be clear again. I have tried moving my return around, but I will try to point it in a diagonally direction. What would be my last resort to get rid of the algae. Attached is a picture of the algae. As you can see, my pool is pretty clear to be standing outside the pool and took this picture. Thank you for any help you can provide.

 

[chem geek]

You might also try using a skimmer sock and see if anything collects in it just in case this is pollen and not algae.

Did you ever try to get rid of this with a yellow/mustard algae SLAM or at least see if an elevated 15% FC/CYA level keeps it from growing?

For yellow/mustard algae, the last resort with the least side effects would be use of a phosphate remover. Sodium bromide products would kill the algae but would turn the pool into a bromine pool for a short while and the algae could return. Just keep in mind that if this turns out to be pollen, then none of these solutions will fix that -- you'd need to capture and filter out pollen as it gets into the pool.