Algae or sediment? Now I think it is the stairs

[Opus4]

I've been following the advice from the Pool School since shortly after we had our AG pool installed last summer and the pool care instructions from the store where we got it consisted of: "Here, put this in it." Instead, I joined this forum, learned how to take care of the pool here, bought the TF100 kit, use Clorox bleach from Costco, and only go to the pool store when I need something from them. So, before I ask my question, I would like to say thanks for all the information contained in the store and on this forum.

I think I've been handling my pool properly, but I am trying to determine whether there could be something growing in it or if I am just getting lots of pollen & other sediment that my cartridge filter isn't catching. First, the latest test results (TF100 kit):

pH - 7.6
TA - 80
FC - 5.5
TC - 5.5
CYA - ~30

There is a fair amount of sediment on the pool bottom that is not picked up by the Pool Rover Jr cleaner nor by vacuuming -- the bottom is cleaned, but the water just becomes cloudy afterwards & settles back to the bottom over the next few days.

When I test (almost daily), CC is almost always 0; once in a while it is 0.5. FC has never been below 2. An overnight test a few days ago showed an FC drop of 0.5.

Based on those numbers & a few comments I've found on the forum regarding dust/pollen on the pool bottom, I'm leaning towards just having sediment that is too fine for the cartridge filter, but since this is my first full summer with a pool, could anything be growing despite hardly ever having any CC and not much FC drop overnight?

If it is only sediment, I'm looking into getting a Slime Bag as a supplemental filter & going back to enjoying my pool.

Thanks for any comments.

 

[duraleigh]

Re: Algae or sediment? I think it is sediment

Hey, Andy,

Welcome to the forum. :lol: Those are very nice numbers! :lol:

Like you, I would lean towards sediment but algae is a very insidious thang and can lurk sometimes when you are not expecting it.

The first thing I would suggest is to try to get some of the suspicious stuff in between your thumb and finger and "roll" it. If it's at all gritty, it's sediment. If it's slimy it's probably some dead algae. Let us know.

 

[Opus4]

Re: Algae or sediment? I think it is sediment

Thanks for the quick reply -- now I know what it is like when people on a different forum used to accuse me of never sleeping after replying quickly!

I'll check out the feel of the stuff tomorrow. For now, all I can say is that it doesn't stick to the liner & creates a cloud when disturbed (wave hand near it, pass brush over the area, etc).

If it turns out to be algae, I wonder if leaving the solar cover off too long can cause algae growth on it, which then gets transferred to the pool when the cover is put back on. That's the only low Cl area I can think of at the moment.

 

[duraleigh]

Re: Algae or sediment? I think it is sediment

If it turns out to be algae, I wonder if leaving the solar cover off too long can cause algae growth on it, which then gets transferred to the pool when the cover is put back on. That's the only low Cl area I can think of at the moment.

That's not a bad thought. I hope we can clearly decide if it's dead algae tomorrow and, if so, I think we can get that cured pretty simply.

 

[Opus4]

Re: Algae or sediment? I think it is sediment

Well, after almost an inch of rain, some cool air, and a cloudy day that prevents the solar system from adding any heat, the pool is cooler than I care to go into.

FC is now 4.5 & CC is 0.5. But, the water now has a very slight green cast to it. I think I'll err on the side of caution and assume that something is growing slowly & just doesn't register much CC nor overnight FC loss and try shocking before it has a chance to get worse. If it really is just a LOT of pollen, then all I've done is wasted some Cl & testing reagent. I think I'll get a Slime Bag anyway because there always seems to be some stuff the cartridge filter doesn't catch.

 

[duraleigh]

Re: Algae or sediment? I think it is sediment

That's a good plan Opus. Shock it thoroughly (green almost always equals algae.....all other factors become sort of irrelevant) and the pool will be crystal clear.

 

[Opus4]

Re: Algae or sediment? I think it is sediment

I don't expect to see results after just a few hours, but I do have one question since this is the first time I've tried shocking: if there was something growing, wouldn't CC go up while shocking? I've been trying to keep FC around 12-13 every hour or 2. The sun has come out from time to time, so that would kill off some FC. When I check it, it goes down to about 10.5 and only 1 time did I barely see CC of 0.5 (very little pink that would have gone away with less than 1 drop of reagent).

Of course, that leads back to my algae vs. sediment confusion. I just keep expecting to see some sort of test result if something is actively growing.


And, am I the only strange person who gets that Sade "Smooth Operator" song stuck in my head every time I use the Pool Calculator?? There must be some sort of lyrics that could be written for that...

 

[mkenyon2]

Re: Algae or sediment? I think it is sediment

And, am I the only strange person who gets that Sade "Smooth Operator" song stuck in my head every time I use the Pool Calculator?? There must be some sort of lyrics that could be written for that...

Doh... I will now!

I'm looking into the Slime Bag, interesting...

While I was shocking, but almost done at the start of the season, I did lay out the solar cover for a while with the pool at shock levels. I figured, that way, anything on the cover would get a cleaning. I didn't leave it in the shock level water for more than 24 hours, but haven't seemed to have any trouble since, even tho the cover comes on and off frequently. Guess what I'm saying is, it can't hurt. Might just have a slight little bit lingering.

 

[Opus4]

Re: Algae or sediment? I think it is sediment

At 6:50 last night, FC was 12.5, CC was 0.5. The sun wasn't shining on the pool after that. At 4:50 this morning, FC was 12.0, CC was 0.5. Unless someone can tell me there could still be something there, I'll just bounce back to the sediment theory & try the Slime Bag I ordered yesterday.

I've seen a few other recent posts that concluded they had lots of pollen. If the Slime Bag clears it all out, I'll just chalk it up to getting some experience.

 

[Opus4]

Re: Algae or sediment? I think it is sediment

To follow up: I'm not sure whether that one afternoon's worth of shocking killed whatever small amount of algae was growing (stopped because of small FC loss overnight & CCs were low) or whether the constant filtering did it, but the pool is much clearer now.

I used the Slime Bag after being away for the weekend. The floor sediment was already mostly gone from the previous week's constant filtering and/or shocking, but the water went from not being able to see underwater from one end of the 30' pool to the other, to being fairly clear all the way across. (Maybe I'm being too picky about how clear I want the water!) The only issue with the Slime Bag is that a cloud of dust goes back into the pool while pulling the bag out of the water. It was suggested that I pull the bag out & clean it more frequently than just letting it go for a day or so. And, I can't leave the bag on all the time since that restricts the return flow & the water isn't stirred up much. I'll probably only use it as supplemental filtering once a week or so.

Oh, and I forgot to mention that I have plastic steps in the pool instead of a ladder. I noticed a lot of stuff settled inside the steps the other day, so for all I know, that is a source of low level algae growth & they sure seem hard to clean out.

 

[Opus4]

Steps are probably the issue

Oh, and I forgot to mention that I have plastic steps in the pool instead of a ladder. I noticed a lot of stuff settled inside the steps the other day, so for all I know, that is a source of low level algae growth & they sure seem hard to clean out.

This must be the problem.

After several days, the sediment was back. Pool was clear. FC levels have tested fine; CC was 0 - 0.5 (barely turned pink when doing the CC test; practically had to put it against white paper to see that it was a little pink). I decided to try a drastic test & just remove the steps. I had tried to clean them out a week ago, but they still dumped green water when I removed them & the weight dumped even greener water. They must be producing a constant low level of algae that doesn't register much with the overnight FC test nor much CC.

I've seen posts about using sealed PVC pipe weights & cutting more holes in the steps. If the pool stays clean after this round of shocking & leaving the steps out for a while, I'll look into modifying the stairs.

 

[RobertScalchi]

Re: Algae or sediment? I think it is sediment

Having the same exact issue/confusion if sediment and or algae on bottom floor. And dont even get me started on that Sade/Smooth Operator song. My wife her family and her friends will never let me live that song down. When I was young and up until recently I always thought the lyrics was scooo- bop- a whaaayllaaa. It's a weekly discussion around my house... lol