Mysterious Re-Appearing Green Film

H2O_Keeper

0
LifeTime Supporter
Nov 8, 2008
140
SW Indiana
I have had a very difficult time clearing my pool all the way back to last Fall. IT started out as a bad Algae bloom which I cleared before winter. When spring came I fought for numerous weeks and even posted on this forum about having a difficult time clearing the haze in my pool. After numerous shocks, clarifiers, flocc treatments etc the haze is gone.

I got to a point now where the water is clear but the bottom has this green film to it. Almost two weeks ago I had everything settle to the bottom, I vaccumed to waste and minus a little floating around from the vaccum it was all clear.

Two weeks later I have the same film back again all over the bottom of pool. I did use a Clarifier (HTH) to help try and grab any of the stuff floating around. It goes in blue and dont think it could be that on the bottom but I am unsure.

Normally I would think if I had Algae It would be all through the pool and my CC would be high. I can clearly see the main drain on the 8' deep end but the pool looks green from a distance (bottom coming through). I can easily push my broom over it and you can get a lot of detail with the blue pool liner.

I am pretty sure I have something not quite filtering correctly and probably some bypass with my filter (Well I am "assuming"). When I try to vacuum this stuff and its not going to waste you can see it come right back in through the returns.

My reason for posting is I really wanted to know what this mystery green film is. I have shocked numerous times and to no avail. Chlorine holds fine overnight. Current test numbers:

FC 3.5
CC <0.5 (barely turned pink)
ALK 100
CH 260
CYA 55

Any clues on what this is, and what to do would be greatly appreciated (am I on track with the filter?). I took it to a 18FC shock last weekend, so any cooties should be gone and held no lower than 3.0 FC the last week.
 
My concern is I wasted a lot of money shocking keeping my FC high during the haze battle. I never loose more than 1FC overnight and never peak to .5 CC.....

Should this hazing over the bottom Algae (even if I am right on the edge and somehow I am not clearing whats on the bottom) be filtering out with a sand filter? Should my filter be catching this stuff during a vacuum instead of going back through the returns?

I have a peristaltic pump and check my pool nightly, since this green stuff was noticed after getting the water clear I have monitored and it has never dropped below a two before the nightly does and have never needed more than one drop for the CC to go from a light pink to clear with the TF100.

Based on being green I do think it probaby is algae but am confused on why the testing doesnt point towards algae and why my filter cant grab it. Can this be typical right on the edge?

.
 
I have read that even though there may be algae, the CC test doesn't always pick it up as CC's. <from duraleigh but can't remember which thread I read it in>

I have to agree with reebok though. You are letting your FC slip below the reccommended FC level with a CYA of 55. Are you dosing your pool every day or are you waiting every couple days? Also, are you brushing your pool regularly? ChemGeek reccomends a good brushing every day just like the dentist reccommends you brush your teeth. :-D
 
Every day at 11pm....I have been averaging adding between 2-3FC per day trying to keep things level (I just put the system in this spring so I dont have it fully dialed in). When I check daily the worst I have ever seen it drop is to 1.5FC before an immediate response getting it back up so I get a 5 reading in the morning. I always check the CC when it gets at or below 2 to make sure I havent dipped to low and CC above 0.5 existis.

Even though I might be teetering on the edge trying to have a 3 at night and 5 in the morning (after dose) as the goal I had assumed since it never went very long below the 3 I would be okay. Perhaps I am just on the edge....

I am guilty about the not brushing though...It usually just sits and only gets stirred up upon use or a sweep/vacc.My question about Algae going through a sand filter, has anyone else experienced this?
 
With a CYA of 55ppm, I'd personally round it up to 60ppm. For a CYA of 60ppm, your target FC should be 7ppm <in the am> and 5ppm on the low side <in the pm>.

I think your issue is clearly a low FC level. I'd shock it if it were my pool.

I don't know what to say about algae coming out of a sand filter. If that were the case, you'd still need to shock it til it's dead and perhaps add DE to the filter to catch smaller microns when the dead algae sank to the bottom and have it swept up and then you could back wash it.

I'm sorry if I'm not getting it... I have a DE filter but the only thing that kills green algae is chlorine, even if it is a film.
 
Thanks Casey.....I just went up to a 7FC and the nightly two more a little later (all the bleach I have in-house). Will take to shock tommorow afternoon and hold for 24 hours and brush it several times.

I have heard sometimes sand filters are right on the edge for bypassing like I am seeing but dont know if its the norm, thus I posed the question. Your 5 micron opposed to my 30-50 could be the difference.
 
H2O_Keeper said:
Will take to shock tommorow afternoon and hold for 24 hours and brush it several times.
.

If you have slime, you have a problem, regardless of if you have <0.5 CC and minimal FC loss. THose are good indicators that all is well, but not necessarily the 'final exam' so to speak.

Shocking is a process, not an event. You need to keep your pool at shock levels longer. You say you have <1ppm FC loss overnight, and <0.5 CC, but you really need to keep shocking until all the stuff is dead. Brush and backwash as needed. I would shock until I had ZERO loss overnight and sparkly non-slimy water!!
 
H2O_Keeper said:
Thanks Casey.....I just went up to a 7FC and the nightly two more a little later (all the bleach I have in-house). Will take to shock tommorow afternoon and hold for 24 hours and brush it several times.

I have heard sometimes sand filters are right on the edge for bypassing like I am seeing but dont know if its the norm, thus I posed the question. Your 5 micron opposed to my 30-50 could be the difference.

I think you will see a BIG difference once you give the boot to the algae with the shocking and start your days at 7ppm. I too would hold the shock level for a few days myself if it's really bad or doesn't look like it's completely cleared after the 24 hours.

As for the sand filters, yeah, there are more gadgets on them and you can re-circulate, filter, backwash :blah: but nothing filters like a DE filter. :cool: Some feel it's a PITA but I wouldn't want anything else!

Try the cup of DE and see how that works.

Keep us posted too! Any pics? :mrgreen:
 
Quick update:

Well you guys are right....Somehow I must of had Algae most of the summer hovering over the bottom of my pool. Early on it appeared to be just kinda like light dirt (appeared more brown/yellow then green), then it started to have a greenish color to it, and then it started to be obviously green at the layer of Algae reaches up only like 1" from the bottom. After several good brushings and the entire pool now green it had to of been algae. I have had the pool at 16+ shock level since Saturday evening (checking several times a day and adding as needed) and as of this morning there was a small tint of green still to it but clear on the shallow end.

I left the robot running all last night so things couldnt settle to the bottom again. This stuff I have just seems to cling more to the bottom, and per the thread apparently I am right on the edge wading off most algae but due to circulation at the bottom not getting FC everywhere. I also have a steep incline from 3.5' to 8' so that probably doesnt help any.

I have a pic of the before (with a brush stroke so we could see what I was talking about) and will post both before and after once I am green clear and get the dead algae out as well.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Another question about the stuff in my pool. Any hint of green appears to be gone (still at shock level tonight, based on what I can see a little hazy on the deep in). I noticed when I came home tonight I had a brown/yellow light coating on my steps. The pool cleaner never gets up there so this explains why it was able to settle there. My concern is that I dont know much about the mustard algae I have read about on this site. Can it haze on the bottom as well?

It is going to take A LOT more chlorine to take it up to mustard algae shock level. How can I tell if I have it? Also if I continue to just hold the normal algae shock level will it eventually burn off but at a slower rate? I have been at 16+ for 72 hours.....

Edit [ I found this link researching Mustard Algae http://www.troublefreepool.com/figh...e-right-track-t12123.html?hilit=mustard algae , I will tough it out at least another 24 hours but I had clusters of what appeared to be dirt and it looked a lot like the pics in that thread. I hope I am wrong. Is it typical to get the Mustard Algae in all parts of the US? Most of the threads I have read about it are in the south. Does anyone know the source of MA]
 
Well I went through the shock process for green algae and everything appeared to be okay the pool was very clear. I noticed at that time there was some areas that just looked like dirt that had accumulated and I hinted of this on my steps.

Over last week I kept my FC at 7 and noticed across the week what appeared to be just dirt areas accumulating various places. We did not swim last week and thought it was odd with no activity. I was gone over the weekend and my Peristaltic kept things at 7 as well over the weekend.

On Sunday the areas were much larger and it was a yellow color. 1/4 of the pool was covered with this dirt/yellow covered stuff. Looks like the mustard algae pics I have seen on this forum. On Sunday night I took it up to 34FC it held okay overnight. I ran the pool cleaner and it stirred things up really bad (which it needed) and then it was very obvious it was ALgae, not just some dirt (greenish yellow color). I did not add anything during the day and it was 16 when I got home in the evening and I took it up to 25 with what chlorine I had onsite.

Currently the pool is a sparkling blue but hazy. My sand filter takes a long time to clear up a breakout even with DE added.

I was studying the bottom and it looks like some dirt sections again (of what I can make out). I am concerned I will go through the same cycle again and perhaps I messed up and did not hold the Mustard algae shock for long enough.

Considering I have to buy enough chlorine to go all the way up to 32 and keep it there for probably several days I am seriously considering one of the yellow-out type alternatives. I have read that they work; however, beware of great chlorine demands after the treatement.

Anyone have any advice on brand and what kind of demand i will go through trying to hold the FC after a yellow-out type kill. Trying to figure out if I'm better off buying a ton of bleach or some yellow out and some extra sodium hypochlorite.

At this stage I will wait and see if it comes back but it is certainly starting to look like before when I thought I was home free....
 
yes, pump on 24/7..... i sincerely thought it was dead algae last time but things kept expanding on the bottom and turned yellow.

I gave it a sweep tonight (cant see bottom on the deep end yet to vacuum). i will keep monitoring.

fc use after yellow-out???
 
If you haven't already, I'd recommend backwashing your filter. I also have a sand filter and when fighting an algae bloom, it helps to backwash more frequently than normal. You'll be surprised at the color of the water that comes out. Getting rid of that dirty water makes the filter more efficient IMO.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.