How can I still have Algae???

SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#1
Happy Easter all!!

I have posted about this problem before, but I guess I'm just too thick to get it.

After a successful SLAM...... ( including OCLT )

For the last several weeks, I have been keeping my FC at 6-8 with a CYA of 55-60 continuously via approx. every other day additions of liquid CL (approx. 80ml every 2 days ) a ph of 7.6-7.8 and alkal of approx. 90. My pool is in the full florida sun all day and I do get a fair amount of leaves daily. ( enough so that there are almost always some oak leaves on the wall at the slower moving portions of the waterline every day....).
I can keep the bottom mostly clean via Navigator, but keeping the surface totally leave-free is next to impossible.
I have had virtually no CC over the last 3 weeks. My water is crystal clear.
The other day I noticed what I thought was a greenish tint on the wall at a corner where the water moves a little slower. I shrugged it off, as I believed with my test #'s, there was no way I could be getting algae. :confused:
Well, lo and behold, went out this morning and BAM, green algae on that corner.....
The only thing I have not been doing is brushing, because it's a giant pool, and well, I'm kinda lazy. I thought with my numbers as good as they were, no need, right?
Duraleigh had told my once that it's possible to have 0 CC and still have algae. I didn't understand that at the time, and obviously, still don't.
Now I believe him.
My understanding is that FC combines with organics and nasties and forms chloramines/cc, and when the level of cc gets high enuf, its time to SLAM.
But what I don't get, is, if I have adequate daily FC which is supposed to be consuming any emerging algae, why don't I show any CC? Is'nt algae a form of organic?
I guess I've been depending too heavily on my numbers alone, and I'm pretty sure I'm gonna get admonished for not pushin that brush, but can someone please explain why my understanding/misunderstanding of this FC/CC/Algae thing is flawed?
BTW: I brushed the pool this morning with my Easter bunny ears on, and started SLAM. I will continue the SLAM until I can pass an OCLT as you have advised.

Thanks all,

Dave.
 

Swampwoman

TFP Expert
LifeTime Supporter
Apr 27, 2012
3,845
Grand Rapids, MI
#2
Is the area you found the algae subject to poor circulation? How many hours a day do you filter?

Before I went swg, I dosed daily and suspect your alternate-day-dosing might contribute to your outcome.

Our recommended levels work virtually all the time but my best guess is that you may experience more success a) testing and dosing to max [fc/cya][/FC/cya] daily instead of every second day, possibly going 1 ppm above your rec level to account for your "dead" zone, or alternately, increasing your circulation/filter time a bit. Also, cya readings should always be rounded up. So 55 should be treated as 60 to account for test variance, which puts your target at 7-9 ppm.

If your not sure if you have a dead zone circulation wise, thew a ping png ball in the pool and watch it travel ;)
 

woodyp

Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
10,216
East Texas
#3
That Florida sun may be burning off any CC generated by killing algae. It sure does in Texas. Brushing required......pic of Easter Bunny ears required!
 

SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#4
SwampWoman-

Thanx for your reply. Yes, the area the algae was in is in what I suspect to be a slow moving corner. I will try the ping pong ball test to confirm. I am currently filtering 24x7 for the last two weeks or so. ( Just had a new timer installed, and haven't set it yet...) I normally filter 8A to 5P. Testing and dosing every day seems like a lot of work, although I understand the concept you propose. Actually, I originally was dosing at 7-9ppm but decided to lower my CYA to around 50 in order to not use so much bleach, which I now realize probably doesn't make any difference in CL use. I think I'll increase my current SLAM levels to 24ppm to concur with the 7-9ppm level you suggested.
 

pooldv

Mod Squad
TFP Expert
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Aug 10, 2012
24,993
DFW, TX
#5
Agree with Woody, a little extra brushing in that area will circulate the water and get the algae off the plaster. I ended up completely reversing my return eyeballs from clockwise to counterclockwise to get rid of a dead spot that collected some debris on the bottom.
 

ff702

Bronze Supporter
May 11, 2016
95
Las Vegas, NV
#8
If you're wanting to add Cl only every other day, my suggestion would be to take your target higher to compensate for the usage until the next dosing.


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SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#10
Swampwoman and Pooldv-

Thanx for your replies. Tried the ping pong ball. It moved very well over the entire surface at a good rate without any stops. Thought the wind might be helping just a little too much, so I dropped in a piece of light string with a light rubber washer on the end to help it sink, but not drag on the bottom. Man, that thing moved right along, at all depth levels and at all wall locations, so I am assuming I have no dead spots. If you saw my recent threads, I recently lowered my CYA from a level of over 100, to approx. 60 via several water replacements. At a level of 60 using the 25ml samples with the Taylor Kit, I was going thru a lot of reagents with FAS-DPD tests keeping my FC @ 7-9. But I had no algae. In order to lower my reagent use, I tried to lower my CYA to 50 or so. I thought I had it at approx. 50, so I lowered my FC level to 6-8 and that is when I got the algae. I think what happened is I am reading my CYA test wrong ( i.e. it actually is closer to 60) but I am chlorinating at a level for a 50 CYA level. Does that make sense?
This CYA test is frustrating to read. Anyway, I am currently SLAMming at a 60 CYA level, i.e. 24ppm FC, and will keep it up for a few days until I can get a clean OCLT. I will then run this pool at a 7-9 FC level and brush weekly per Pooldv. Do ya'll test FAS-DPD every day? or how often? I use a lot of reagent. Is the 10ml FC test accurate enuf?
 

Swampwoman

TFP Expert
LifeTime Supporter
Apr 27, 2012
3,845
Grand Rapids, MI
#11
. Do ya'll test FAS-DPD every day? or how often?
I used to do ph and FC daily when I was a "chlorine carrier" (eg before I switched to SWG.) Now its more like every second day. I check the rest of the parameters much less frequently as they rarely change much.

The way I look at it is reagents are cheap compared to the trouble I fend off ;)

I think your theory on the cya is likely correct and that just giving yourself a bit of headroom going forward will find you troube free.
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#12
Do the OTO every other day for sure and the FAS/PDP the alternate days. You'll see it get a paler yellow on the OTO if your falling too low.

Right now you're doing a hopefully quick Shock L&M so you need to do the FAS/PDP every day until you don't have excessive FC loss overnight and pass the OCLT.

There's never any substitute for chlorine. Trying to run it on the edge to save money will cost more in the long run in terms of time, headache and money spent on more chlorine than if you just maintain it at a higher level to begon with.. Pay me now or pay me later.

Remember also that the recommended FC/CyA ratio put the sanitizer level just above that needed to kill bacteria so if you have algae the risk of issues with bacteria are there and although they're quite easy to kill off you don't want to go there with your FC levels.

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SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#13
OK. An update on my current SLAM and a couple a questions............

here are my numbers since I initially noticed green algae on one of my walls and initiated SLAM:

sun 4/16 0900 Add 320 oz 12.5% chlorine
sun 4/16 1330 FC 22 Add 64 oz 12.5% chlorine
sun 4/16 1430 Add 160 oz 12.5% chlorine
sun 4/16 1830 FC 20.8 Add 160 oz 12.5% chlorine for overnite
mon 4/17 0800 FC 25.4 Add 80 oz 12.5% chlorine
mon 4/17 1200 FC 25
mon 4/17 1600 FC 22 Add 160 oz 12.5% chlorine
mon 4/17 2030 FC 24.8
tues 4/18 0900 FC 22 Add 160 oz 12.5% chlorine
tues 4/18 1430 FC 21.4 Add 240 oz 12.5% chlorine
tues 4/18 2000 FC 24.4 Add 80 oz 12.5% chlorine
wed 4/19 0630 FC 22 Add 160 oz 12.5% chlorine
 

Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
14,999
Midland TX
#14
You will learn your pool, and need to test FAS/DPD as little as once a week once you have kept it clean, clear, and Algae free for a good while. I strongly suggest that until you do have that long term cleanliness in place, use the DPD test at least a few times a week until you really learn your pool. Same with pH. Do both of them as often as you like, but at least that much while you're learning it.

Once you get to a point you can predict about what your tests will show, and what the pool needs in response, you can spread out the testing further, and further. Until then, follow that, and you will master your pool. :whip:
 

SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#15
Oops............. didn't mean to hit reply yet........ anyhoo, After that last entry, I have 5 more entries on Thurs, none of which fell below 24, which is my target for my cya. actually, the last 5-6 entries over the last coupla days are in the 25-28 range. During this SLAM, I've never had CC more than .5, and on some tests, none. Anyway, the reason I posted is that during the initial few days of this slam, I dipped down into the low 20's a few times. My water was always clear. However, early this morning, after almost 3 days of 24+ FC and before this vaporizing, hot Florida sun came out, I found a lot of white detritus on the bottom which I quickly vacuumed up, brushed the sides, and BW my filter. I assume this represents breakpoint chlorination? Finally.... Which brings me to ask... Would the temporary swings between my FC22, FC20 and FC24 during specific days be enuf to prevent me from completing SLAM? I think I already know the answer and it is SLAMaintain. But since I didn't get what I assume to be breakpoint until after a couple a days of 25-28 FC is there a possibility my CYA figures are off, and I actually need to raise my SLAM FC levels?
 

duraleigh

Admin
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In The Industry
Apr 1, 2007
31,333
Sebring, Florida
#16
Breakpoint chlorination is a myth. The notion that there is some magic "point" where FC suddenly clears your pool is simply not correct and has been dispelled for several years.

Following the SLAM procedure we teach to the letter will clear your pool.
 

SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#17
Duraleigh-

I guess I used the term "breakpoint" incorrectly. What I meant was during my initial days of the SLAM, my FC repeatedly dipped below my SLAM target of 24 FC for my CYA level of 60. It wasn't until I kept FC constantly above 24 for a day or two that I finally saw the results of the SLAM on the pool bottom, i.e. the FC was finally high enuf, long enuf to oxidize ( break down ) some nasties. Since then, I have constantly kept my FC above 24, have yet to pass an OCLT, and noticed some more detritus on the floor this am. I will continue with my SLAM until I can pass an OCLT. BTW... I am currently running my pump 24/7, I assume it's OK for the pump to be running overnite during my OCLT?
 

SupaDave

Bronze Supporter
Nov 25, 2016
28
Tampa, Florida
#20
:kim:Passed my OCLT last nite!!!! NO FC loss overnite. Lotsa brushin and CL, but thanks all for your suggestions and thoughts. I'm gonna continue my SLAM levels just one more day, followed by another OCLT in the AM. Probably overkill, but just to satisfy my OCD. ;)
Thanx again,
Dave